user ns: Introduction
Subsystems (5)
cover user ns: Introduction
This patchset adds a user namespace, which allows a process to unshare its user_struct table, allowing for separate accounting per user namespace. It appends a user namespace to vfsmounts and fown_structs, so that uid1==uid2 checks can be extended to be false if uid1 and uid2 are in different namespaces.
A vfsmount generally cannot be accessed by another user namespace than that in which it was mounted. A vfsmount can be mounted "shared-ns", in which case it can be accessed by any user namespace. This is needed at least to bootstrap a container so it can get far enough to create it's own private file system tree, and can be used in conjunction with read-only bind mounts to provide shared /usr trees, for instance. However, for more useful, more fine-grained sharing accross user namespaces, it has been suggested that a new filesystem specifying global userid's be used.
Patches are as follows:
1. make exit_task_namespaces extern to prevent future compile failure.
2. add userns framework.
3. add userns pointer to vfsmount
4. hook permission to check current against vfsmount userns
5. prepare for copy_mnt and copy_tree to return -EPERM
6. implement shared mounts which can cross user namespaces
7. implement user ns checks for file sigio
8. implement user namespace unshare
Following is a test program to verify that the cross-user-namespace mount permissions are working correctly. The attached patches pass both this test and LTP.
thanks,
-serge
#include <unistd.h>
#include <linux/unistd.h>
#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>
#include <sys/mount.h>
#include <sys/syscall.h>
#include <errno.h>
#include <signal.h>
#ifndef MNT_DETACH
#define MNT_DETACH 2
#endif
#ifndef MS_SHARE_NS
#define MS_SHARE_NS 1<<22
#endif
#ifndef CLONE_NEWUSER
#define CLONE_NEWUSER 0x10000000
#endif
#define PIPEREAD 0
#define PIPEWRITE 1
static inline _syscall2(int, clone, int, flags, int, foo) int to1[2], from1[1], to2[2], from2[2];
void do_test1(void)
{
int ret;
int fd;
char buf[100];
rmdir("/mnt1");
ret = mkdir("/mnt1", 0666);
if (ret == -1) {
perror("mkdir mnt1");
_exit(1);
}
ret = mount("/", "/mnt1", "none", MS_BIND, "");
if (ret == -1) {
perror("mount mnt1");
_exit(1);
}
fd = open("/mnt1/testme", O_RDWR|O_CREAT);
if (fd == -1) {
printf("thread 1: unable to write /testme: ERROR\n");
} else {
write(fd, "a", 1);
printf("thread 1: able to write /testme: GOOD\n");
close(fd);
}
write(from1[PIPEWRITE], "mount", 6);
read(to1[PIPEREAD], buf, 2);
umount("/mnt1");
printf("thread 1: exiting.\n");
write(from1[PIPEWRITE], "done", 5);
rmdir("/mnt1");
}void do_test2(void)
{
int ret;
char buf[100];
int fd;
rmdir("/mnt2");
ret = mkdir("/mnt2", 0666);
if (ret == -1) {
perror("mkdir mnt2");
_exit(1);
}
ret = read(to2[PIPEREAD], buf, 10);
fd = open("/testme", O_RDWR|O_CREAT);
if (fd == -1) {
printf("thread 2: unable to write /testme: ERROR\n");
} else {
write(fd, "b", 1);
printf("thread 2: able to write /testme: GOOD\n");
close(fd);
}
fd = open("/mnt1/testme", O_RDWR|O_CREAT);
if (fd == -1) {
printf("thread 2: unable to open /mnt1/testme: GOOD\n");
} else {
write(fd, "c", 1);
printf("thread 2: able to open /mnt1/testme: ERROR\n");
close(fd);
}
/* now try remounting /mnt1 to /mnt2 */
ret = mount("/mnt1", "/mnt2", "none", MS_BIND, "");
if (ret == -1) {
printf("thread2: unable to remount /mnt1 to /mnt2: GOOD\n");
} else {
perror("thread2: able to remount /mnt1 to /mnt2: BAD\n");
fd = open("/mnt2/testme", O_RDWR|O_CREAT);
if (fd == -1) {
printf("thread 2: unable to open /mnt2/testme: GOOD\n");
} else {
write(fd, "d", 1);
printf("thread 2: able to open /mnt2/testme: ERROR\n");
close(fd);
}
umount ("/mnt2");
}
write(from2[PIPEWRITE], "done", 5);
printf("thread 2: exiting\n");
rmdir("/mnt2");
}int main(int argc, char *argv[])
{
int childpid1, childpid2;
int ret;
char buf[100];
ret = mount("/", "/mnt", "none", MS_SHARE_NS | MS_BIND, "");
if (ret == -1) {
perror("failed to mount /mnt shared_ns.\n");
_exit(1);
}
chdir("/mnt");
chroot("/mnt");
ret = pipe(to1);
if (ret == -1) {
perror("failed to create child pipe 1\n");
_exit(1);
}
ret = pipe(to2);
if (ret == -1) {
perror("failed to create child pipe 2\n");
_exit(1);
}
ret = pipe(from1);
if (ret == -1) {
perror("failed to create child pipe 1\n");
_exit(1);
}
ret = pipe(from2);
if (ret == -1) {
perror("failed to create child pipe 2\n");
_exit(1);
}
childpid1 = clone(CLONE_NEWUSER | SIGCHLD, 0);
if (childpid1 != 0) {
do_test1();
_exit(0);
}
childpid2 = clone(CLONE_NEWUSER | SIGCHLD, 0);
if (childpid2 != 0) {
do_test2();
_exit(0);
}
read(from1[PIPEREAD], buf, 5);
write(to2[PIPEWRITE], "go", 3);
read(from2[PIPEREAD], buf, 4);
write(to1[PIPEWRITE], "go", 3);
read(from1[PIPEREAD], buf, 4);
return 0;
}PATCH 1/8 nsproxy: externalizes exit_task_namespaces
From: Cedric Le Goater <[email protected]>
Subject: [PATCH -mm 1/8] nsproxy: externalizes exit_task_namespaces
this is required to remove a header dependency in sched.h which breaks next patches.
--- include/linux/nsproxy.h | 15 ++++----------- kernel/nsproxy.c | 11 +++++++++++ 2 files changed, 15 insertions(+), 11 deletions(-)
include/linux/nsproxy.h +4 -11
@@ -2,7 +2,8 @@ #ifndef _LINUX_NSPROXY_H#define _LINUX_NSPROXY_H#include <linux/spinlock.h> -#include <linux/sched.h> + +struct task_struct ;struct mnt_namespace ;struct uts_namespace ;
@@ -43,14 +44,6 @@ static inline void put_nsproxy(struct ns } } -static inline void exit_task_namespaces (struct task_struct *p) -{ -struct nsproxy *ns = p->nsproxy; -if (ns) { -task_lock (p); - p->nsproxy =NULL ; -task_unlock (p); -put_nsproxy (ns); - } -} +extern void exit_task_namespaces (struct task_struct *p); +#endif
kernel/nsproxy.c +11 -0
@@ -36,6 +36,17 @@ void get_task_namespaces(struct task_str } } +void exit_task_namespaces (struct task_struct *p) +{ +struct nsproxy *ns = p->nsproxy; +if (ns) { +task_lock (p); + p->nsproxy =NULL ; +task_unlock (p); +put_nsproxy (ns); + } +} +/* * creates a copy of "orig" with refcount 1. * This does not grab references to the contained namespaces,
Signature · 1 line
1.4.1
PATCH 2/8 user namespace: add the framework
In reply to Serge E. HallynFrom: Cedric Le Goater <[email protected]>
Subject: [PATCH -mm 2/8] user namespace: add the framework
This patch adds the user namespace struct and framework
Basically, it will allow a process to unshare its user_struct table, resetting at the same time its own user_struct and all the associated accounting.
A new root user (uid == 0) is added to the user namespace upon creation. Such root users have full privileges and it seems that theses privileges should be controlled through some means (process capabilities ?)
The unshare is not included in this patch.
Changes since [try #4]:
- Updated get_user_ns and put_user_ns to accept NULL, and get_user_ns to return the namespace.
Changes since [try #3]:
- moved struct user_namespace to files user_namespace.{c,h}
Changes since [try #2]:
- removed struct user_namespace* argument from find_user()
Changes since [try #1]:
- removed struct user_namespace* argument from find_user()
- added a root_user per user namespace
--- include/linux/init_task.h | 2 ++ include/linux/nsproxy.h | 1 + include/linux/sched.h | 3 ++ include/linux/user_namespace.h | 53 ++++++++++++++++++++++++++++++++++++++++ init/Kconfig | 8 ++++++ kernel/Makefile | 2 +- kernel/fork.c | 2 +- kernel/nsproxy.c | 12 +++++++++ kernel/sys.c | 5 ++-- kernel/user.c | 18 +++++++------- kernel/user_namespace.c | 44 +++++++++++++++++++++++++++++++++ 11 files changed, 136 insertions(+), 14 deletions(-)
include/linux/init_task.h +2 -0
@@ -8,6 +8,7 @@ #include <linux/utsname.h>#include <linux/lockdep.h> #include <linux/ipc.h> #include <linux/pid_namespace.h> +#include <linux/user_namespace.h> #define INIT_FDTABLE \ { \
@@ -78,6 +79,7 @@ #define INIT_NSPROXY(nsproxy) { \ .uts_ns = &init_uts_ns, \ .mnt_ns = NULL, \ INIT_IPC_NS(ipc_ns) \ + .user_ns = &init_user_ns, \ }#define INIT_SIGHAND (sighand) { \
include/linux/nsproxy.h +1 -0
@@ -29,6 +29,7 @@ struct nsproxy {struct ipc_namespace *ipc_ns;struct mnt_namespace *mnt_ns;struct pid_namespace *pid_ns; +struct user_namespace *user_ns; };extern struct nsproxy init_nsproxy;
include/linux/sched.h +2 -1
@@ -252,6 +252,7 @@ extern signed long schedule_timeout_unin asmlinkage void schedule(void);struct nsproxy ; +struct user_namespace ;/* Maximum number of active map areas.. This is a random (large) number */ #define DEFAULT_MAX_MAP_COUNT 65536
@@ -1285,7 +1286,7 @@ extern struct task_struct *find_task_by_extern void __set_special_pids (pid_t session,pid_t pgrp);/* per-UID process charging. */ -extern struct user_struct *alloc_uid (uid_t ); +extern struct user_struct *alloc_uid (struct user_namespace *,uid_t );static inline struct user_struct *get_uid (struct user_struct *u) {atomic_inc (&u->__count);
include/linux/user_namespace.h new file +53 -0
53 lines not on this page · raw message
init/Kconfig +8 -0
@@ -222,6 +222,14 @@ config UTS_NS vservers, to use uts namespaces to provide different uts info for different servers. If unsure, say N. +config USER_NS + bool "User Namespaces" + default n + help + Support user namespaces. This allows containers, i.e. + vservers, to use user namespaces to provide different + user info for different servers. If unsure, say N. + config AUDIT bool "Auditing support" depends on NET
kernel/Makefile +1 -1
@@ -4,7 +4,7 @@ # obj-y = sched.o fork.o exec_domain.o panic.o printk.o profile.o \ exit.o itimer.o time.o softirq.o resource.o \ - sysctl.o capability.o ptrace.o timer.o user.o \ + sysctl.o capability.o ptrace.o timer.o user.o user_namespace.o \ signal.o sys.o kmod.o workqueue.o pid.o \ rcupdate.o extable.o params.o posix-timers.o \ kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \
kernel/fork.c +1 -1
@@ -996,7 +996,7 @@ #endifif (atomic_read (&p->user->processes) >= p->signal->rlim[RLIMIT_NPROC ].rlim_cur) {if (!capable (CAP_SYS_ADMIN ) && !capable (CAP_SYS_RESOURCE ) && - p->user != &root_user) + p->user != current->nsproxy->user_ns->root_user) goto bad_fork_free; }
kernel/nsproxy.c +12 -0
@@ -80,6 +80,8 @@ struct nsproxy *dup_namespaces(struct nsget_ipc_ns (ns->ipc_ns);if (ns->pid_ns)get_pid_ns (ns->pid_ns); +if (ns->user_ns) +get_user_ns (ns->user_ns); }return ns;
@@ -127,10 +129,18 @@ int copy_namespaces(int flags, struct taif (err) goto out_pid; + err =copy_user_ns (flags, tsk); +if (err) + goto out_user; + out:put_nsproxy (old_ns);return err; +out_user: +if (new_ns->pid_ns) +put_pid_ns (new_ns->pid_ns); + out_pid:if (new_ns->ipc_ns)put_ipc_ns (new_ns->ipc_ns);
@@ -156,5 +166,7 @@ void free_nsproxy(struct nsproxy *ns)put_ipc_ns (ns->ipc_ns);if (ns->pid_ns)put_pid_ns (ns->pid_ns); +if (ns->user_ns) +put_user_ns (ns->user_ns);kfree (ns); }
kernel/sys.c +3 -2
@@ -33,6 +33,7 @@ #include <linux/getcpu.h>#include <linux/compat.h> #include <linux/syscalls.h> #include <linux/kprobes.h> +#include <linux/user_namespace.h> #include <asm/uaccess.h> #include <asm/io.h>
@@ -1070,13 +1071,13 @@ static int set_user(uid_t new_ruid, int {struct user_struct *new_user; - new_user =alloc_uid (new_ruid); + new_user =alloc_uid (current->nsproxy->user_ns, new_ruid);if (!new_user)return -EAGAIN ;if (atomic_read (&new_user->processes) >= current->signal->rlim[RLIMIT_NPROC ].rlim_cur && - new_user != &root_user) { + new_user != current->nsproxy->user_ns->root_user) {free_uid (new_user);return -EAGAIN ; }
kernel/user.c +9 -9
@@ -14,20 +14,19 @@ #include <linux/slab.h>#include <linux/bitops.h> #include <linux/key.h> #include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/user_namespace.h> /* * UID task count cache, to get fast user lookup in "alloc_uid" * when changing user ID's (ie setuid() and friends). */ -#define UIDHASH_BITS (CONFIG_BASE_SMALL ? 3 : 8) -#define UIDHASH_SZ (1 << UIDHASH_BITS)#define UIDHASH_MASK (UIDHASH_SZ - 1)#define __uidhashfn (uid) (((uid >> UIDHASH_BITS) + uid) & UIDHASH_MASK) -#define uidhashentry (uid) (uidhash_table + __uidhashfn((uid))) +#define uidhashentry (ns, uid) ((ns)->uidhash_table + __uidhashfn((uid)))static struct kmem_cache *uid_cachep; -static struct list_head uidhash_table[UIDHASH_SZ ];/* * The uidhash_lock is mostly taken from process context, but it is
@@ -94,9 +93,10 @@ struct user_struct *find_user(uid_t uid) {struct user_struct *ret;unsigned long flags; +struct user_namespace *ns = current->nsproxy->user_ns;spin_lock_irqsave (&uidhash_lock, flags); - ret =uid_hash_find (uid,uidhashentry (uid)); + ret =uid_hash_find (uid,uidhashentry (ns, uid));spin_unlock_irqrestore (&uidhash_lock, flags);return ret; }
@@ -120,9 +120,9 @@ void free_uid(struct user_struct *up) } } -struct user_struct *alloc_uid (uid_t uid) +struct user_struct *alloc_uid (struct user_namespace *ns,uid_t uid) { -struct list_head *hashent =uidhashentry (uid); +struct list_head *hashent =uidhashentry (ns, uid);struct user_struct *up;spin_lock_irq (&uidhash_lock);
@@ -211,11 +211,11 @@ static int __init uid_cache_init(void) 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL, NULL);for (n =0 ; n <UIDHASH_SZ ; ++n) -INIT_LIST_HEAD (uidhash_table + n); +INIT_LIST_HEAD (init_user_ns.uidhash_table + n);/* Insert the root user immediately (init already runs as root) */ spin_lock_irq (&uidhash_lock); -uid_hash_insert (&root_user,uidhashentry (0 )); +uid_hash_insert (&root_user,uidhashentry (&init_user_ns,0 ));spin_unlock_irq (&uidhash_lock);return 0 ;
kernel/user_namespace.c new file +44 -0
44 lines not on this page · raw message
Signature · 1 line
1.4.1
Re: [PATCH -mm 2/8] user namespace: add the framework
From: Serge E. Hallyn <[email protected]>
Subject: [PATCH 1/1] user ns: fix compilation failures for some arches
for i386, an include of utsname.h by asm/elf.h hides the fact that user_namespace needs sched.h. To fix compilation for x86_64, just include sched.h explicitly.
--- include/linux/user_namespace.h | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)
include/linux/user_namespace.h +1 -0
@@ -3,6 +3,7 @@ #define _LINUX_USER_NAMESPACE_H#include <linux/kref.h> #include <linux/nsproxy.h> +#include <linux/sched.h> #define UIDHASH_BITS (CONFIG_BASE_SMALL ? 3 : 8)#define UIDHASH_SZ (1 << UIDHASH_BITS)
Signature · 1 line
1.4.1
PATCH 3/8 user ns: add user_namespace ptr to vfsmount
In reply to Serge E. HallynFrom: Serge E. Hallyn <[email protected]>
Subject: [PATCH -mm 3/8] user ns: add user_namespace ptr to vfsmount
Add user_namespace ptr to vfsmount, and define a helper to compare it to the task's user_ns.
--- fs/namespace.c | 3 +++ include/linux/mount.h | 2 ++ include/linux/sched.h | 20 ++++++++++++++++++++ 3 files changed, 25 insertions(+), 0 deletions(-)
fs/namespace.c +3 -0
@@ -25,6 +25,7 @@ #include <linux/namei.h>#include <linux/security.h> #include <linux/mount.h> #include <linux/ramfs.h> +#include <linux/user_namespace.h> #include <asm/uaccess.h> #include <asm/unistd.h> #include "pnode.h"
@@ -55,6 +56,7 @@ struct vfsmount *alloc_vfsmnt(const char {struct vfsmount *mnt =kmem_cache_zalloc (mnt_cache,GFP_KERNEL );if (mnt) { + mnt->mnt_user_ns =get_user_ns (current->nsproxy->user_ns);atomic_set (&mnt->mnt_count,1 );INIT_LIST_HEAD (&mnt->mnt_hash);INIT_LIST_HEAD (&mnt->mnt_child);
@@ -87,6 +89,7 @@ EXPORT_SYMBOL(simple_set_mnt);void free_vfsmnt (struct vfsmount *mnt) { +put_user_ns (mnt->mnt_user_ns);kfree (mnt->mnt_devname);kmem_cache_free (mnt_cache, mnt); }
include/linux/mount.h +2 -0
@@ -21,6 +21,7 @@ struct super_block;struct vfsmount ;struct dentry ;struct mnt_namespace ; +struct user_namespace ;#define MNT_NOSUID 0x01#define MNT_NODEV 0x02
@@ -53,6 +54,7 @@ struct vfsmount {struct list_head mnt_slave;/* slave list entry */ struct vfsmount *mnt_master;/* slave is on master->mnt_slave_list */ struct mnt_namespace *mnt_ns;/* containing namespace */ +struct user_namespace *mnt_user_ns;/* namespace for uid interpretation */ /* * We put mnt_count & mnt_expiry_mark at the end of struct vfsmount * to let these frequently modified fields in a separate cache line
include/linux/sched.h +20 -0
@@ -83,6 +83,8 @@ #include <linux/resource.h>#include <linux/timer.h> #include <linux/hrtimer.h> #include <linux/task_io_accounting.h> +#include <linux/nsproxy.h> +#include <linux/mount.h> #include <asm/processor.h>
@@ -1586,6 +1588,24 @@ extern int cond_resched_lock(spinlock_textern int cond_resched_softirq (void );/* +* Check whether a task and a vfsmnt belong to the same uidns. +* Since the initial namespace is exempt from these checks, +* return 1 if so. Also return 1 if the vfsmnt is exempt from +* such checking. Otherwise, if the uid namespaces are different, +* return 0. +*/ +static inline int task_mnt_same_uidns (struct task_struct *tsk, +struct vfsmount *mnt) +{ +if (tsk->nsproxy == init_task.nsproxy) +return 1 ; +if (mnt->mnt_user_ns == tsk->nsproxy->user_ns) +return 1 ; +return 0 ; +} + + +/* * Does a critical section need to be broken due to another * task waiting?: */
Signature · 1 line
1.4.1
PATCH 4/8 user ns: hook permission
In reply to Serge E. HallynFrom: Serge E. Hallyn <[email protected]>
Subject: [PATCH -mm 4/8] user ns: hook permission
Hook permission to check vfsmnt->user_ns against current.
--- fs/namei.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-)
fs/namei.c +4 -0
@@ -246,6 +246,8 @@ int permission(struct inode *inode, intreturn -EACCES ; } +if (nd && !task_mnt_same_uidns (current, nd->mnt)) +return -EACCES ;/* * MAY_EXEC on regular files requires special handling: We override
@@ -433,6 +435,8 @@ static int exec_permission_lite(struct i {umode_t mode = inode->i_mode; +if (!task_mnt_same_uidns (current, nd->mnt)) +return -EACCES ;if (inode->i_op && inode->i_op->permission)return -EAGAIN ;
Signature · 1 line
1.4.1
PATCH 5/8 user ns: prepare copy_tree, copy_mnt, and their callers to handle errs
In reply to Serge E. HallynFrom: Serge E. Hallyn <[email protected]>
Subject: [PATCH -mm 5/8] user ns: prepare copy_tree, copy_mnt, and their callers to handle errs
With shareduserns and non-shareduserns mounts, it will be possible for clone_mnt to return -EPERM if a namespace tries to bind mount a non-shareduserns vfsmnt from another user namespace. But currently they only return NULL, which is interpreted as -ENOMEM. Update the callers to handle other errors.
--- fs/namespace.c | 20 ++++++++++++-------- fs/pnode.c | 5 +++-- 2 files changed, 15 insertions(+), 10 deletions(-)
fs/namespace.c +12 -8
@@ -708,8 +708,9 @@ struct vfsmount *copy_tree(struct vfsmoureturn NULL ; res = q =clone_mnt (mnt, dentry, flag); -if (!q) - goto Enomem; +if (!q ||IS_ERR (q)) { +return q; + } q->mnt_mountpoint = mnt->mnt_mountpoint; p = mnt;
@@ -730,8 +731,9 @@ struct vfsmount *copy_tree(struct vfsmou nd.mnt = q; nd.dentry = p->mnt_mountpoint; q =clone_mnt (p, p->mnt_root, flag); -if (!q) - goto Enomem; +if (!q ||IS_ERR (q)) { + goto Error; + }spin_lock (&vfsmount_lock);list_add_tail (&q->mnt_list, &res->mnt_list);attach_mnt (q, &nd);
@@ -739,7 +741,7 @@ struct vfsmount *copy_tree(struct vfsmou } }return res; -Enomem: +Error:if (res) {LIST_HEAD (umount_list);spin_lock (&vfsmount_lock);
@@ -747,7 +749,7 @@ Enomem:spin_unlock (&vfsmount_lock);release_mounts (&umount_list); } -return NULL ; +return q; }/*
@@ -927,8 +929,10 @@ static int do_loopback(struct nameidataelse mnt =clone_mnt (old_nd.mnt, old_nd.dentry,0 ); -if (!mnt) +if (!mnt ||IS_ERR (mnt)) { + err = mnt ?PTR_ERR (mnt) : -ENOMEM ; goto out; + } err =graft_tree (mnt, nd);if (err) {
@@ -1465,7 +1469,7 @@ struct mnt_namespace *dup_mnt_ns(struct/* First pass: copy the tree topology */ new_ns->root =copy_tree (mnt_ns->root, mnt_ns->root->mnt_root,CL_COPY_ALL |CL_EXPIRE ); -if (!new_ns->root) { +if (!new_ns->root ||IS_ERR (new_ns->root)) {up_write (&namespace_sem);kfree (new_ns);return NULL ;
fs/pnode.c +3 -2
@@ -187,8 +187,9 @@ int propagate_mnt(struct vfsmount *dest_ source =get_source (m, prev_dest_mnt, prev_src_mnt, &type); -if (!(child =copy_tree (source, source->mnt_root, type))) { - ret = -ENOMEM ; + child =copy_tree (source, source->mnt_root, type); +if (!child ||IS_ERR (child)) { + ret = child ?PTR_ERR (child) : -ENOMEM ;list_splice (tree_list, tmp_list.prev); goto out; }
Signature · 1 line
1.4.1
Re: [PATCH -mm 5/8] user ns: prepare copy_tree, copy_mnt, and their callers to handle errs
Quoted 29 lines · Serge E. Hallyn
fs/namespace.c +6
-4@@ -708,8 +708,9 @@ struct vfsmount *copy_tree(struct vfsmoureturn NULL ; res = q =clone_mnt (mnt, dentry, flag); -if (!q) - goto Enomem; +if (!q ||IS_ERR (q)) { +return q; + } q->mnt_mountpoint = mnt->mnt_mountpoint; p = mnt;@@ -730,8 +731,9 @@ struct vfsmount *copy_tree(struct vfsmou nd.mnt = q; nd.dentry = p->mnt_mountpoint; q =clone_mnt (p, p->mnt_root, flag); -if (!q) - goto Enomem; +if (!q ||IS_ERR (q)) { + goto Error; + }spin_lock (&vfsmount_lock);list_add_tail (&q->mnt_list, &res->mnt_list);attach_mnt (q, &nd);
fs/namespace.c struct vfsmount *copy_tree(struct vfsmou · line 745
Quoted 6 lines
fs/namespace.c +1
-1@@ -739,7 +741,7 @@ struct vfsmount *copy_tree(struct vfsmou } }return res; -Enomem: +Error:if (res) {
^^^^^^^^^^
I think that this check can be safely skiped, as res is always non-NULL when Error: is now reached, isn't it?
Regards,
Frederik
Re: [PATCH -mm 5/8] user ns: prepare copy_tree, copy_mnt, and their callers to handle errs
Quoted 37 lines · Frederik Deweerdt
Quoted 29 lines · Serge E. Hallyn
fs/namespace.c +6
-4@@ -708,8 +708,9 @@ struct vfsmount *copy_tree(struct vfsmoureturn NULL ; res = q =clone_mnt (mnt, dentry, flag); -if (!q) - goto Enomem; +if (!q ||IS_ERR (q)) { +return q; + } q->mnt_mountpoint = mnt->mnt_mountpoint; p = mnt;@@ -730,8 +731,9 @@ struct vfsmount *copy_tree(struct vfsmou nd.mnt = q; nd.dentry = p->mnt_mountpoint; q =clone_mnt (p, p->mnt_root, flag); -if (!q) - goto Enomem; +if (!q ||IS_ERR (q)) { + goto Error; + }spin_lock (&vfsmount_lock);list_add_tail (&q->mnt_list, &res->mnt_list);attach_mnt (q, &nd);fs/namespace.c struct vfsmount *copy_tree(struct vfsmou · line 745
Quoted 6 lines
fs/namespace.c +1
-1@@ -739,7 +741,7 @@ struct vfsmount *copy_tree(struct vfsmou } }return res; -Enomem: +Error:if (res) {^^^^^^^^^^
Quoted 2 lines
I think that this check can be safely skiped, as res is always non-NULL when Error: is now reached, isn't it?
Good point. In addition, we can clean the code up a little by not letting clone_mnt return NULL. Compile-tested patch follows. Though really it starts to look like clone_mnt should be split into two parts, with the original clone_mnt static inline, and the new clone_mnt doing the permission check and return value conversion...
From: Serge E. Hallyn <[email protected]>
Subject: [PATCH 1/1] userns: cleanups with clone_mnt
As Frederik Deweerdt points out, the Error: case in copy_tree() can no longer have res==NULL, so remove that check.
Also make clone_mnt always return -ENOMEM in place of NULL.
--- fs/namespace.c | 90 ++++++++++++++++++++++++++++---------------------------- 1 files changed, 45 insertions(+), 45 deletions(-)
fs/namespace.c +45 -45
@@ -243,41 +243,43 @@ static struct vfsmount *clone_mnt(struct mnt =alloc_vfsmnt (old->mnt_devname); -if (mnt) { - mnt->mnt_flags = old->mnt_flags; -atomic_inc (&sb->s_active); - mnt->mnt_sb = sb; - mnt->mnt_root =dget (root); - mnt->mnt_mountpoint = mnt->mnt_root; - mnt->mnt_parent = mnt; - -if (flag &CL_SLAVE ) { -list_add (&mnt->mnt_slave, &old->mnt_slave_list); - mnt->mnt_master = old; -CLEAR_MNT_SHARED (mnt); - }else { -if ((flag &CL_PROPAGATION ) ||IS_MNT_SHARED (old)) -list_add (&mnt->mnt_share, &old->mnt_share); -if (IS_MNT_SLAVE (old)) -list_add (&mnt->mnt_slave, &old->mnt_slave); - mnt->mnt_master = old->mnt_master; - } -if (flag &CL_MAKE_SHARED ) -set_mnt_shared (mnt); -if (flag &CL_SHARE_NS ) - mnt->mnt_flags |=MNT_SHARE_NS ; -else - mnt->mnt_flags &= ~MNT_SHARE_NS ; - -/* stick the duplicate mount on the same expiry list -* as the original if that was on one */ -if (flag &CL_EXPIRE ) { -spin_lock (&vfsmount_lock); -if (!list_empty (&old->mnt_expire)) -list_add (&mnt->mnt_expire, &old->mnt_expire); -spin_unlock (&vfsmount_lock); - } +if (!mnt) +return ERR_PTR (-ENOMEM ); + + mnt->mnt_flags = old->mnt_flags; +atomic_inc (&sb->s_active); + mnt->mnt_sb = sb; + mnt->mnt_root =dget (root); + mnt->mnt_mountpoint = mnt->mnt_root; + mnt->mnt_parent = mnt; + +if (flag &CL_SLAVE ) { +list_add (&mnt->mnt_slave, &old->mnt_slave_list); + mnt->mnt_master = old; +CLEAR_MNT_SHARED (mnt); + }else { +if ((flag &CL_PROPAGATION ) ||IS_MNT_SHARED (old)) +list_add (&mnt->mnt_share, &old->mnt_share); +if (IS_MNT_SLAVE (old)) +list_add (&mnt->mnt_slave, &old->mnt_slave); + mnt->mnt_master = old->mnt_master; } +if (flag &CL_MAKE_SHARED ) +set_mnt_shared (mnt); +if (flag &CL_SHARE_NS ) + mnt->mnt_flags |=MNT_SHARE_NS ; +else + mnt->mnt_flags &= ~MNT_SHARE_NS ; + +/* stick the duplicate mount on the same expiry list +* as the original if that was on one */ +if (flag &CL_EXPIRE ) { +spin_lock (&vfsmount_lock); +if (!list_empty (&old->mnt_expire)) +list_add (&mnt->mnt_expire, &old->mnt_expire); +spin_unlock (&vfsmount_lock); + } +return mnt; }
@@ -715,14 +717,15 @@ struct vfsmount *copy_tree(struct vfsmou {struct vfsmount *res, *p, *q, *r, *s;struct nameidata nd; +LIST_HEAD (umount_list);if (!(flag &CL_COPY_ALL ) &&IS_MNT_UNBINDABLE (mnt))return NULL ; res = q =clone_mnt (mnt, dentry, flag); -if (!q ||IS_ERR (q)) { +if (IS_ERR (q))return q; - } + q->mnt_mountpoint = mnt->mnt_mountpoint; p = mnt;
@@ -743,9 +746,8 @@ struct vfsmount *copy_tree(struct vfsmou nd.mnt = q; nd.dentry = p->mnt_mountpoint; q =clone_mnt (p, p->mnt_root, flag); -if (!q ||IS_ERR (q)) { +if (IS_ERR (q)) goto Error; - }spin_lock (&vfsmount_lock);list_add_tail (&q->mnt_list, &res->mnt_list);attach_mnt (q, &nd);
@@ -754,13 +756,11 @@ struct vfsmount *copy_tree(struct vfsmou }return res; Error: -if (res) { -LIST_HEAD (umount_list); -spin_lock (&vfsmount_lock); -umount_tree (res,0 , &umount_list); -spin_unlock (&vfsmount_lock); -release_mounts (&umount_list); - } +spin_lock (&vfsmount_lock); +umount_tree (res,0 , &umount_list); +spin_unlock (&vfsmount_lock); +release_mounts (&umount_list); +return q; }
Signature · 1 line
1.4.1
PATCH 6/8 user ns: implement shared mounts
In reply to Serge E. HallynFrom: Serge E. Hallyn <[email protected]>
Subject: [PATCH -mm 6/8] user ns: implement shared mounts
Implement shared-ns mounts, which allow containers in different user namespaces to share mounts. Without this, containers can obviously never even be started.
Here is a sample smount.c (based on Miklos' version) which only does a bind mount of arg1 onto arg2, but making the destination a shared-ns mount.
int main(int argc, char *argv[])
{
int type;
if(argc != 3) {
fprintf(stderr, "usage: %s src dest", argv[0]);
return 1;
}
fprintf(stdout, "%s %s %s\n", argv[0], argv[1], argv[2]);
type = MS_SHARE_NS | MS_BIND;
setfsuid(getuid());
if(mount(argv[1], argv[2], "none", type, "") == -1) {
perror("mount");
return 1;
}
return 0;
}--- fs/namespace.c | 30 ++++++++++++++++++++++++------ fs/pnode.h | 1 + include/linux/fs.h | 1 + include/linux/mount.h | 1 + include/linux/sched.h | 2 ++ 5 files changed, 29 insertions(+), 6 deletions(-)
fs/namespace.c +24 -6
@@ -234,7 +234,14 @@ static struct vfsmount *clone_mnt(struct int flag) {struct super_block *sb = old->mnt_sb; -struct vfsmount *mnt =alloc_vfsmnt (old->mnt_devname); +struct vfsmount *mnt; + +if (!(old->mnt_flags &MNT_SHARE_NS )) { +if (old->mnt_user_ns != current->nsproxy->user_ns) +return ERR_PTR (-EPERM ); + } + + mnt =alloc_vfsmnt (old->mnt_devname);if (mnt) { mnt->mnt_flags = old->mnt_flags;
@@ -257,6 +264,10 @@ static struct vfsmount *clone_mnt(struct }if (flag &CL_MAKE_SHARED )set_mnt_shared (mnt); +if (flag &CL_SHARE_NS ) + mnt->mnt_flags |=MNT_SHARE_NS ; +else + mnt->mnt_flags &= ~MNT_SHARE_NS ;/* stick the duplicate mount on the same expiry list * as the original if that was on one */
@@ -368,6 +379,7 @@ static int show_vfsmnt(struct seq_file * { MNT_NOSUID, ",nosuid" }, { MNT_NODEV, ",nodev" }, { MNT_NOEXEC, ",noexec" }, + { MNT_SHARE_NS, ",share_userns" }, { MNT_NOATIME, ",noatime" }, { MNT_NODIRATIME, ",nodiratime" }, { MNT_RELATIME, ",relatime" },
@@ -902,11 +914,14 @@ static int do_change_type(struct nameida/* * do loopback mount. */ -static int do_loopback (struct nameidata *nd,char *old_name,int recurse) +static int do_loopback (struct nameidata *nd,char *old_name,int recurse, +int uidns_share) {struct nameidata old_nd;struct vfsmount *mnt =NULL ;int err =mount_is_safe (nd); +int flag = (uidns_share ?CL_SHARE_NS :0 ); +if (err)return err;if (!old_name || !*old_name)
@@ -925,9 +940,9 @@ static int do_loopback(struct nameidata err = -ENOMEM ;if (recurse) - mnt =copy_tree (old_nd.mnt, old_nd.dentry,0 ); + mnt =copy_tree (old_nd.mnt, old_nd.dentry, flag);else - mnt =clone_mnt (old_nd.mnt, old_nd.dentry,0 ); + mnt =clone_mnt (old_nd.mnt, old_nd.dentry, flag);if (!mnt ||IS_ERR (mnt)) { err = mnt ?PTR_ERR (mnt) : -ENOMEM ;
@@ -1414,9 +1429,11 @@ long do_mount(char *dev_name, char *dir_ mnt_flags |=MNT_NODIRATIME ;if (flags &MS_RELATIME ) mnt_flags |=MNT_RELATIME ; +if (flags &MS_SHARE_NS ) + mnt_flags |=MNT_SHARE_NS ; flags &= ~(MS_NOSUID |MS_NOEXEC |MS_NODEV |MS_ACTIVE | -MS_NOATIME |MS_NODIRATIME |MS_RELATIME ); +MS_NOATIME |MS_NODIRATIME |MS_RELATIME |MS_SHARE_NS );/* ... and get the mountpoint */ retval =path_lookup (dir_name,LOOKUP_FOLLOW , &nd);
@@ -1431,7 +1448,8 @@ long do_mount(char *dev_name, char *dir_ retval =do_remount (&nd, flags & ~MS_REMOUNT , mnt_flags, data_page); else if (flags & MS_BIND) - retval =do_loopback (&nd, dev_name, flags &MS_REC ); + retval =do_loopback (&nd, dev_name, flags &MS_REC , + mnt_flags &MNT_SHARE_NS ); else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE)) retval =do_change_type (&nd, flags); else if (flags & MS_MOVE)
fs/pnode.h +1 -0
@@ -22,6 +22,7 @@ #define CL_SLAVE 0x02#define CL_COPY_ALL 0x04#define CL_MAKE_SHARED 0x08#define CL_PROPAGATION 0x10 +#define CL_SHARE_NS 0x20static inline void set_mnt_shared (struct vfsmount *mnt) {
include/linux/fs.h +1 -0
@@ -121,6 +121,7 @@ #define MS_PRIVATE (1<<18) /* change to#define MS_SLAVE (1<<19)/* change to slave */ #define MS_SHARED (1<<20)/* change to shared */ #define MS_RELATIME (1<<21)/* Update atime relative to mtime/ctime. */ +#define MS_SHARE_NS (1<<22)/* ignore user namespaces for permission */ #define MS_ACTIVE (1<<30)#define MS_NOUSER (1<<31)
include/linux/mount.h +1 -0
@@ -35,6 +35,7 @@ #define MNT_SHRINKABLE 0x100#define MNT_SHARED 0x1000/* if the vfsmount is a shared mount */ #define MNT_UNBINDABLE 0x2000/* if the vfsmount is a unbindable mount */ #define MNT_PNODE_MASK 0x3000/* propogation flag mask */ +#define MNT_SHARE_NS 0x4000/* ignore user namespaces for permission */ struct vfsmount {struct list_head mnt_hash;
include/linux/sched.h +2 -0
@@ -1599,6 +1599,8 @@ static inline int task_mnt_same_uidns(st {if (tsk->nsproxy == init_task.nsproxy)return 1 ; +if (mnt->mnt_flags &MNT_SHARE_NS ) +return 1 ;if (mnt->mnt_user_ns == tsk->nsproxy->user_ns)return 1 ;return 0 ;
Signature · 1 line
1.4.1
PATCH 7/8 user_ns: handle file sigio
In reply to Serge E. HallynFrom: Serge E. Hallyn <[email protected]>
Subject: [PATCH -mm 7/8] user_ns: handle file sigio
A process in one user namespace could set a fowner and sigio on a file in a shared vfsmount, ending up killing a task in another user namespace.
Prevent this by adding a user namespace pointer to the fown_struct, and enforcing that a process causing a signal to be sent be in the same user namespace as the file owner.
--- fs/fcntl.c | 14 +++++++++++--- fs/file_table.c | 2 ++ include/linux/fs.h | 1 + 3 files changed, 14 insertions(+), 3 deletions(-)
fs/fcntl.c +11 -3
@@ -18,6 +18,7 @@ #include <linux/security.h>#include <linux/ptrace.h> #include <linux/signal.h> #include <linux/rcupdate.h> +#include <linux/user_namespace.h> #include <asm/poll.h> #include <asm/siginfo.h>
@@ -250,15 +251,18 @@ static int setfl(int fd, struct file * f }static void f_modown (struct file *filp,struct pid *pid,enum pid_type type, -uid_t uid,uid_t euid,int force) +uid_t uid,uid_t euid,struct user_namespace *user_ns, +int force) {write_lock_irq (&filp->f_owner.lock);if (force || !filp->f_owner.pid) {put_pid (filp->f_owner.pid); +put_user_ns (filp->f_owner.user_ns); filp->f_owner.pid =get_pid (pid); filp->f_owner.pid_type = type; filp->f_owner.uid = uid; filp->f_owner.euid = euid; + filp->f_owner.user_ns =get_user_ns (user_ns); }write_unlock_irq (&filp->f_owner.lock); }
@@ -272,7 +276,8 @@ int __f_setown(struct file *filp, structif (err)return err; -f_modown (filp, pid, type, current->uid, current->euid, force); +f_modown (filp, pid, type, current->uid, current->euid, + current->nsproxy->user_ns, force);return 0 ; }EXPORT_SYMBOL (__f_setown);
@@ -298,7 +303,7 @@ EXPORT_SYMBOL(f_setown);void f_delown (struct file *filp) { -f_modown (filp,NULL ,PIDTYPE_PID ,0 ,0 ,1 ); +f_modown (filp,NULL ,PIDTYPE_PID ,0 ,0 ,NULL ,1 ); }pid_t f_getown (struct file *filp)
@@ -455,6 +460,9 @@ static const long band_table[NSIGPOLL] =static inline int sigio_perm (struct task_struct *p,struct fown_struct *fown,int sig) { +if (fown->user_ns != init_task.nsproxy->user_ns && + fown->user_ns != p->nsproxy->user_ns) +return 0 ; return (((fown->euid == 0) || (fown->euid == p->suid) || (fown->euid == p->uid) || (fown->uid == p->suid) || (fown->uid == p->uid)) &&
fs/file_table.c +2 -0
@@ -21,6 +21,7 @@ #include <linux/cdev.h>#include <linux/fsnotify.h> #include <linux/sysctl.h> #include <linux/percpu_counter.h> +#include <linux/user_namespace.h> #include <asm/atomic.h>
@@ -175,6 +176,7 @@ void fastcall __fput(struct file *file)if (file->f_mode &FMODE_WRITE )put_write_access (inode);put_pid (file->f_owner.pid); +put_user_ns (file->f_owner.user_ns);file_kill (file); file->f_path.dentry =NULL ; file->f_path.mnt =NULL ;
include/linux/fs.h +1 -0
@@ -685,6 +685,7 @@ struct fown_struct {struct pid *pid;/* pid or -pgrp where SIGIO should be sent */ enum pid_type pid_type;/* Kind of process group SIGIO should be sent to */ uid_t uid, euid;/* uid/euid of process setting the owner */ +struct user_namespace *user_ns;/* namespace to which uid belongs */ int signum;/* posix.1b rt signal to be delivered on IO */ };
Signature · 1 line
1.4.1
Re: [PATCH -mm 7/8] user_ns: handle file sigio
Quoted 6 lines · On Thu, 4 Jan 2007 12:12:57 -0600 "Serge E. Hallyn" <[email protected]> wrote:
A process in one user namespace could set a fowner and sigio on a file in a shared vfsmount, ending up killing a task in another user namespace.
Prevent this by adding a user namespace pointer to the
fown_struct, and enforcing that a process causing a signal to be sent be in the same user namespace as the file owner.
This patch breaks the X server (stock FC5 install) with CONFIG_USER_NS=n. Neither the USB mouse nor the trackpad work. They work OK under GPM.
Setting CONFIG_USER_NS=y "fixes" this. This bug was not observed in 2.6.20-rc3-mm1 because that kernel had user-ns-always-on.patch for other reasons. (I'll restore that patch).
There's nothing very interesting here:
sony:/home/akpm> diff -u Xorg.0.log.good Xorg.0.log.bad
Xorg.0.log.bad 2007-01-11 21:17:31.000000000 -0800 renamed from Xorg.0.log.good 2007-01-11 21:11:11.000000000 -0800 +7 -7
@@ -6,7 +6,7 @@ Release Date: 21 December 2005 X Protocol Version 11, Revision 0, Release 7.0 Build Operating System:Linux 2.6.9-22.18.bz155725.ELsmp i686Red Hat, Inc. -Current Operating System: Linux sony 2.6.20-rc4-mm1 #15 Thu Jan 11 21:07:58 PST 2007 i686 +Current Operating System: Linux sony 2.6.20-rc4-mm1 #16 Thu Jan 11 21:14:03 PST 2007 i686 Build Date: 22 March 2006 Before reporting problems, check http://wiki.x.org to make sure that you have the latest version.
@@ -14,7 +14,7 @@ Markers: (--) probed, (**) from config file, (==) default setting, (++) from command line, (!!) notice, (II) informational, (WW) warning, (EE) error, (NI) not implemented, (??) unknown. -(==) Log file: "/var/log/Xorg.0.log", Time: Thu Jan 11 21:10:16 2007 +(==) Log file: "/var/log/Xorg.0.log", Time: Thu Jan 11 21:16:39 2007 (==) Using config file: "/etc/X11/xorg.conf" (==) ServerLayout "single head configuration" (**) |-->Screen "Screen0" (0)
@@ -2117,9 +2117,9 @@ (II) I810(0): Allocated 128 kB for the ring buffer at 0x0 (II) I810(0): Allocating at least 256 scanlines for pixmap cache (II) I810(0): Initial framebuffer allocation size: 12288 kByte -(II) I810(0): Allocated 4 kB for HW cursor at 0xffff000 (0x35dd3000) -(II) I810(0): Allocated 16 kB for HW (ARGB) cursor at 0xfffb000 (0x35e78000) -(II) I810(0): Allocated 4 kB for Overlay registers at 0xfffa000 (0x35e39000). +(II) I810(0): Allocated 4 kB for HW cursor at 0xffff000 (0x358d5000) +(II) I810(0): Allocated 16 kB for HW (ARGB) cursor at 0xfffb000 (0x35888000) +(II) I810(0): Allocated 4 kB for Overlay registers at 0xfffa000 (0x358d7000). (II) I810(0): Allocated 64 kB for the scratch buffer at 0xffea000 drmOpenDevice: node name is /dev/dri/card0 drmOpenDevice: open result is -1, (No such device or address)
@@ -2137,8 +2137,8 @@ (II) I810(0): [drm] loaded kernel module for "i915" driver (II) I810(0): [drm] DRM interface version 1.3 (II) I810(0): [drm] created "i915" driver at busid "pci:0000:00:02.0" -(II) I810(0): [drm] added 8192 byte SAREA at 0xf8e46000 -(II) I810(0): [drm] mapped SAREA 0xf8e46000 to 0xb7eec000 +(II) I810(0): [drm] added 8192 byte SAREA at 0xf8d4a000 +(II) I810(0): [drm] mapped SAREA 0xf8d4a000 to 0xb7f23000 (II) I810(0): [drm] framebuffer handle = 0xc0020000 (II) I810(0): [drm] added 1 reserved context for kernel (II) I810(0): Allocated 32 kB for the logical context at 0xffe2000.
Re: [PATCH -mm 7/8] user_ns: handle file sigio
Quoted 55 lines · Andrew Morton
Quoted 6 lines · On Thu, 4 Jan 2007 12:12:57 -0600 "Serge E. Hallyn" <[email protected]> wrote:
A process in one user namespace could set a fowner and sigio on a file in a shared vfsmount, ending up killing a task in another user namespace.
Prevent this by adding a user namespace pointer to the
fown_struct, and enforcing that a process causing a signal to be sent be in the same user namespace as the file owner.This patch breaks the X server (stock FC5 install) with
CONFIG_USER_NS=n. Neither the USB mouse nor the trackpad work. They work OK under GPM.Setting
CONFIG_USER_NS=y"fixes" this. This bug was not observed in 2.6.20-rc3-mm1 because that kernel had user-ns-always-on.patch for other reasons. (I'll restore that patch).There's nothing very interesting here:
sony:/home/akpm> diff -u Xorg.0.log.good Xorg.0.log.bad
Xorg.0.log.bad 2007-01-11 21:17:31.000000000 -0800 renamed from Xorg.0.log.good 2007-01-11 21:11:11.000000000 -0800 +5
-5@@ -6,7 +6,7 @@ Release Date: 21 December 2005 X Protocol Version 11, Revision 0, Release 7.0 Build Operating System:Linux 2.6.9-22.18.bz155725.ELsmp i686Red Hat, Inc. -Current Operating System: Linux sony 2.6.20-rc4-mm1 #15 Thu Jan 11 21:07:58 PST 2007 i686 +Current Operating System: Linux sony 2.6.20-rc4-mm1 #16 Thu Jan 11 21:14:03 PST 2007 i686 Build Date: 22 March 2006 Before reporting problems, check http://wiki.x.org to make sure that you have the latest version.@@ -14,7 +14,7 @@ Markers: (--) probed, (**) from config file, (==) default setting, (++) from command line, (!!) notice, (II) informational, (WW) warning, (EE) error, (NI) not implemented, (??) unknown. -(==) Log file: "/var/log/Xorg.0.log", Time: Thu Jan 11 21:10:16 2007 +(==) Log file: "/var/log/Xorg.0.log", Time: Thu Jan 11 21:16:39 2007 (==) Using config file: "/etc/X11/xorg.conf" (==) ServerLayout "single head configuration" (**) |-->Screen "Screen0" (0)@@ -2117,9 +2117,9 @@ (II) I810(0): Allocated 128 kB for the ring buffer at 0x0 (II) I810(0): Allocating at least 256 scanlines for pixmap cache (II) I810(0): Initial framebuffer allocation size: 12288 kByte -(II) I810(0): Allocated 4 kB for HW cursor at 0xffff000 (0x35dd3000) -(II) I810(0): Allocated 16 kB for HW (ARGB) cursor at 0xfffb000 (0x35e78000) -(II) I810(0): Allocated 4 kB for Overlay registers at 0xfffa000 (0x35e39000). +(II) I810(0): Allocated 4 kB for HW cursor at 0xffff000 (0x358d5000) +(II) I810(0): Allocated 16 kB for HW (ARGB) cursor at 0xfffb000 (0x35888000) +(II) I810(0): Allocated 4 kB for Overlay registers at 0xfffa000 (0x358d7000). (II) I810(0): Allocated 64 kB for the scratch buffer at 0xffea000 drmOpenDevice: node name is /dev/dri/card0 drmOpenDevice: open result is -1, (No such device or address)
Xorg.0.log.bad 2007-01-11 21:17:31.000000000 -0800 line 2144
Quoted 10 lines
Xorg.0.log.bad 2007-01-11 21:17:31.000000000 -0800 renamed from Xorg.0.log.good 2007-01-11 21:11:11.000000000 -0800 +2
-2@@ -2137,8 +2137,8 @@ (II) I810(0): [drm] loaded kernel module for "i915" driver (II) I810(0): [drm] DRM interface version 1.3 (II) I810(0): [drm] created "i915" driver at busid "pci:0000:00:02.0" -(II) I810(0): [drm] added 8192 byte SAREA at 0xf8e46000 -(II) I810(0): [drm] mapped SAREA 0xf8e46000 to 0xb7eec000 +(II) I810(0): [drm] added 8192 byte SAREA at 0xf8d4a000 +(II) I810(0): [drm] mapped SAREA 0xf8d4a000 to 0xb7f23000 (II) I810(0): [drm] framebuffer handle = 0xc0020000 (II) I810(0): [drm] added 1 reserved context for kernel (II) I810(0): Allocated 32 kB for the logical context at 0xffe2000.
I can't see any reason for this in the code or comparative ltp runs. Cedric is testing on a fc6 laptop, hopefully he can reproduce it.
thanks,
-serge
Re: [PATCH -mm 7/8] user_ns: handle file sigio
Quoted 19 lines · Serge E. Hallyn
Quoted 17 lines · Andrew Morton
Quoted 6 lines · On Thu, 4 Jan 2007 12:12:57 -0600 "Serge E. Hallyn" <[email protected]> wrote:
A process in one user namespace could set a fowner and sigio on a file in a shared vfsmount, ending up killing a task in another user namespace.
Prevent this by adding a user namespace pointer to the
fown_struct, and enforcing that a process causing a signal to be sent be in the same user namespace as the file owner.This patch breaks the X server (stock FC5 install) with
CONFIG_USER_NS=n. Neither the USB mouse nor the trackpad work. They work OK under GPM.Setting
CONFIG_USER_NS=y"fixes" this. This bug was not observed in 2.6.20-rc3-mm1 because that kernel had user-ns-always-on.patch for other reasons. (I'll restore that patch).There's nothing very interesting here:
[ ... ]
Quoted 3 lines
I can't see any reason for this in the code or comparative ltp runs. Cedric is testing on a fc6 laptop, hopefully he can reproduce it.
I did reproduce it on a FC5 desktop finally.
get_user_ns() returns NULL when CONFIG_USER_NS=n and this breaks sigio_perm() which does not expect NULL values for ->user_ns.
I would fix this with the following patch.
C.
--- include/linux/user_namespace.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
include/linux/user_namespace.h +1 -1
@@ -49,7 +49,7 @@static inline struct user_namespace *get_user_ns (struct user_namespace *ns) { -return NULL ; +return &init_user_ns; } static inline int unshare_user_ns(unsigned long flags,
Re: [PATCH -mm 7/8] user_ns: handle file sigio
Quoted 22 lines · Cedric Le Goater
Quoted 19 lines · Serge E. Hallyn
Quoted 17 lines · Andrew Morton
Quoted 6 lines · On Thu, 4 Jan 2007 12:12:57 -0600 "Serge E. Hallyn" <[email protected]> wrote:
A process in one user namespace could set a fowner and sigio on a file in a shared vfsmount, ending up killing a task in another user namespace.
Prevent this by adding a user namespace pointer to the
fown_struct, and enforcing that a process causing a signal to be sent be in the same user namespace as the file owner.This patch breaks the X server (stock FC5 install) with
CONFIG_USER_NS=n. Neither the USB mouse nor the trackpad work. They work OK under GPM.Setting
CONFIG_USER_NS=y"fixes" this. This bug was not observed in 2.6.20-rc3-mm1 because that kernel had user-ns-always-on.patch for other reasons. (I'll restore that patch).There's nothing very interesting here:
[ ... ]
Quoted 1 line
Quoted 7 lines
Quoted 2 lines
I can't see any reason for this in the code or comparative ltp runs. Cedric is testing on a fc6 laptop, hopefully he can reproduce it.
I did reproduce it on a FC5 desktop finally.
get_user_ns()returns NULL whenCONFIG_USER_NS=nand this breakssigio_perm()which does not expect NULL values for ->user_ns.
Argh.
Thanks, Cedric.
Rewriting the userns testcases right now. Clearly, in addition to separately testing clone and unshare, I need to add a sigioperm check, and have a separate set of testcases for CONFIG_USER_NS=n.
thanks,
-serge
Quoted 6 lines
I would fix this with the following patch.
C.
Signed-off-by Cedric Le Goater <[email protected]>
Quoted 17 lines
--- include/linux/user_namespace.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)Index:
2.6.20-rc4-mm1/include/linux/user_namespace.h
===================================================================include/linux/user_namespace.h +1
-1@@ -49,7 +49,7 @@static inline struct user_namespace *get_user_ns (struct user_namespace *ns) { -return NULL ; +return &init_user_ns; } static inline int unshare_user_ns(unsigned long flags,
Re: [PATCH -mm 7/8] user_ns: handle file sigio
[ ... ]
Quoted 3 lines
Rewriting the userns testcases right now. Clearly, in addition to separately testing clone and unshare, I need to add a sigioperm check, and have a separate set of testcases for
CONFIG_USER_NS=n.
Could we get rid of CONFIG_USER_NS ?
It doesn't look that useful anyway, it just deactivates the unshare capability for the user namespace.
Same question for the other mainline namespaces, IPC and utsname.
C.
PATCH 1/1 user_ns: remove CONFIG_USER_NS
It doesn't look that useful anyway, it just deactivates the unshare capability for the user namespace.
--- include/linux/sched.h | 9 --------- include/linux/user_namespace.h | 33 --------------------------------- init/Kconfig | 4 ---- kernel/user_namespace.c | 3 --- 4 files changed, 49 deletions(-)
include/linux/sched.h +0 -9
@@ -1603,7 +1603,6 @@ extern int cond_resched(void);extern int cond_resched_lock (spinlock_t * lock);extern int cond_resched_softirq (void ); -#ifdef CONFIG_USER_NS /* * Check whether a task and a vfsmnt belong to the same uidns. * Since the initial namespace is exempt from these checks,
@@ -1622,14 +1621,6 @@ static inline int task_mnt_same_uidns(streturn 1 ;return 0 ; } -#else -static inline int task_mnt_same_uidns (struct task_struct *tsk, -struct vfsmount *mnt) -{ -return 1 ; -} -#endif -/* * Does a critical section need to be broken due to another
include/linux/user_namespace.h +0 -33
@@ -16,8 +16,6 @@ struct user_namespace {extern struct user_namespace init_user_ns; -#ifdef CONFIG_USER_NS -static inline struct user_namespace *get_user_ns (struct user_namespace *ns) {if (ns)
@@ -45,35 +43,4 @@ static inline int clone_mnt_userns_permi return 1; } -#else - -static inline struct user_namespace *get_user_ns (struct user_namespace *ns) -{ -return NULL ; -} - -static inline int unshare_user_ns (unsigned long flags, -struct user_namespace **new_user) -{ -if (flags &CLONE_NEWUSER ) -return -EINVAL ; - -return 0 ; -} - -static inline int copy_user_ns (int flags,struct task_struct *tsk) -{ -return 0 ; -} - -static inline void put_user_ns (struct user_namespace *ns) -{ -} - -static inline int clone_mnt_userns_permission (struct vfsmount *old) -{ -return 1 ; -} -#endif -#endif /* _LINUX_USER_H */
init/Kconfig +0 -4
@@ -222,10 +222,6 @@ config UTS_NS vservers, to use uts namespaces to provide different uts info for different servers. If unsure, say N. -config USER_NS - bool - default y - config AUDIT bool "Auditing support" depends on NET
kernel/user_namespace.c +0 -3
@@ -19,7 +19,6 @@ struct user_namespace init_user_ns = {EXPORT_SYMBOL_GPL (init_user_ns); -#ifdef CONFIG_USER_NS /* * Clone a new ns copying an original user ns, setting refcount to 1 * @old_ns: namespace to clone
@@ -110,5 +109,3 @@ void free_user_ns(struct kref *kref) ns = container_of(kref, struct user_namespace, kref);kfree (ns); } - -#endif /* CONFIG_USER_NS */
Re: [PATCH -mm] user_ns: remove CONFIG_USER_NS
Quoted 4 lines · Cedric Le Goater
It doesn't look that useful anyway, it just deactivates the unshare capability for the user namespace.
Signed-off-by Cedric Le Goater <[email protected]>
Agreed on both this and CONFIG_UTS_NS. (I haven't looked closely enough at the CONFIG_IPC_NS case yet)
thanks,
-serge
Quoted 116 lines
--- include/linux/sched.h | 9 --------- include/linux/user_namespace.h | 33 --------------------------------- init/Kconfig | 4 ---- kernel/user_namespace.c | 3 --- 4 files changed, 49 deletions(-)Index:
2.6.20-rc4-mm1/include/linux/sched.h
===================================================================include/linux/sched.h +0
-9@@ -1603,7 +1603,6 @@ extern int cond_resched(void);extern int cond_resched_lock (spinlock_t * lock);extern int cond_resched_softirq (void ); -#ifdef CONFIG_USER_NS /* * Check whether a task and a vfsmnt belong to the same uidns. * Since the initial namespace is exempt from these checks, @@ -1622,14 +1621,6 @@ static inline int task_mnt_same_uidns(streturn 1 ;return 0 ; } -#else -static inline int task_mnt_same_uidns (struct task_struct *tsk, -struct vfsmount *mnt) -{ -return 1 ; -} -#endif -/* * Does a critical section need to be broken due to another Index:
2.6.20-rc4-mm1/include/linux/user_namespace.h
===================================================================include/linux/user_namespace.h +0
-33@@ -16,8 +16,6 @@ struct user_namespace {extern struct user_namespace init_user_ns; -#ifdef CONFIG_USER_NS -static inline struct user_namespace *get_user_ns (struct user_namespace *ns) {if (ns)@@ -45,35 +43,4 @@ static inline int clone_mnt_userns_permi return 1; } -#else - -static inline struct user_namespace *get_user_ns (struct user_namespace *ns) -{ -return NULL ; -} - -static inline int unshare_user_ns (unsigned long flags, -struct user_namespace **new_user) -{ -if (flags &CLONE_NEWUSER ) -return -EINVAL ; - -return 0 ; -} - -static inline int copy_user_ns (int flags,struct task_struct *tsk) -{ -return 0 ; -} - -static inline void put_user_ns (struct user_namespace *ns) -{ -} - -static inline int clone_mnt_userns_permission (struct vfsmount *old) -{ -return 1 ; -} -#endif -#endif /* _LINUX_USER_H */ Index: 2.6.20-rc4-mm1/init/Kconfig
===================================================================init/Kconfig +0
-4@@ -222,10 +222,6 @@ config UTS_NS vservers, to use uts namespaces to provide different uts info for different servers. If unsure, say N. -config USER_NS - bool - default y - config AUDIT bool "Auditing support" depends on NETIndex:
2.6.20-rc4-mm1/kernel/user_namespace.c
===================================================================kernel/user_namespace.c +0
-3@@ -19,7 +19,6 @@ struct user_namespace init_user_ns = {EXPORT_SYMBOL_GPL (init_user_ns); -#ifdef CONFIG_USER_NS /* * Clone a new ns copying an original user ns, setting refcount to 1 * @old_ns: namespace to clone @@ -110,5 +109,3 @@ void free_user_ns(struct kref *kref) ns = container_of(kref, struct user_namespace, kref);kfree (ns); } - -#endif /* CONFIG_USER_NS */
PATCH 8/8 user ns: implement user ns unshare
In reply to Serge E. HallynFrom: Serge E. Hallyn <[email protected]>
Subject: [PATCH -mm 8/8] user ns: implement user ns unshare
Implement CLONE_NEWUSER flag useable at clone/unshare.
--- include/linux/sched.h | 1 + include/linux/user_namespace.h | 10 +++++ kernel/fork.c | 22 ++++++++++-- kernel/nsproxy.c | 2 + kernel/user_namespace.c | 74 +++++++++++++++++++++++++++++++++++++++- 5 files changed, 102 insertions(+), 7 deletions(-)
include/linux/sched.h +1 -0
@@ -26,6 +26,7 @@ #define CLONE_CHILD_SETTID 0x01000000 /*#define CLONE_STOPPED 0x02000000/* Start in stopped state */ #define CLONE_NEWUTS 0x04000000/* New utsname group? */ #define CLONE_NEWIPC 0x08000000/* New ipcs */ +#define CLONE_NEWUSER 0x10000000/* New user namespace */ /* * Scheduling policies
include/linux/user_namespace.h +10 -0
@@ -25,6 +25,7 @@ static inline struct user_namespace *get }extern int copy_user_ns (int flags,struct task_struct *tsk); +extern int unshare_user_ns (unsigned long flags,struct user_namespace **new_user);extern void free_user_ns (struct kref *kref);static inline void put_user_ns (struct user_namespace *ns)
@@ -40,6 +41,15 @@ static inline struct user_namespace *getreturn NULL ; } +static inline int unshare_user_ns (unsigned long flags, +struct user_namespace **new_user) +{ +if (flags &CLONE_NEWUSER ) +return -EINVAL ; + +return 0 ; +} +static inline int copy_user_ns (int flags,struct task_struct *tsk) {return 0 ;
kernel/fork.c +18 -4
@@ -49,6 +49,7 @@ #include <linux/cn_proc.h>#include <linux/delayacct.h> #include <linux/taskstats_kern.h> #include <linux/random.h> +#include <linux/user_namespace.h> #include <asm/pgtable.h> #include <asm/pgalloc.h>
@@ -1620,6 +1621,7 @@ asmlinkage long sys_unshare(unsigned lonstruct nsproxy *new_nsproxy =NULL , *old_nsproxy =NULL ;struct uts_namespace *uts, *new_uts =NULL ;struct ipc_namespace *ipc, *new_ipc =NULL ; +struct user_namespace *user, *new_user =NULL ;check_unshare_flags (&unshare_flags);
@@ -1627,7 +1629,7 @@ asmlinkage long sys_unshare(unsigned lon err = -EINVAL ;if (unshare_flags & ~(CLONE_THREAD |CLONE_FS |CLONE_NEWNS |CLONE_SIGHAND |CLONE_VM |CLONE_FILES |CLONE_SYSVSEM | -CLONE_NEWUTS |CLONE_NEWIPC )) +CLONE_NEWUTS |CLONE_NEWIPC |CLONE_NEWUSER )) goto bad_unshare_out;if ((err =unshare_thread (unshare_flags)))
@@ -1648,18 +1650,20 @@ asmlinkage long sys_unshare(unsigned lon goto bad_unshare_cleanup_semundo;if ((err =unshare_ipcs (unshare_flags, &new_ipc))) goto bad_unshare_cleanup_uts; +if ((err =unshare_user_ns (unshare_flags, &new_user))) + goto bad_unshare_cleanup_ipc; -if (new_ns || new_uts || new_ipc) { +if (new_ns || new_uts || new_ipc || new_user) { old_nsproxy = current->nsproxy; new_nsproxy =dup_namespaces (old_nsproxy);if (!new_nsproxy) { err = -ENOMEM ; - goto bad_unshare_cleanup_ipc; + goto bad_unshare_cleanup_user; } }if (new_fs || new_ns || new_mm || new_fd || new_ulist || - new_uts || new_ipc) { + new_uts || new_ipc || new_user) {task_lock (current);
@@ -1707,12 +1711,22 @@ asmlinkage long sys_unshare(unsigned lon new_ipc = ipc; } +if (new_user) { + user = current->nsproxy->user_ns; + current->nsproxy->user_ns = new_user; + new_user = user; + } +task_unlock (current); }if (new_nsproxy)put_nsproxy (new_nsproxy); +bad_unshare_cleanup_user: +if (new_user) +put_user_ns (new_user); + bad_unshare_cleanup_ipc:if (new_ipc)put_ipc_ns (new_ipc);
kernel/nsproxy.c +1 -1
@@ -102,7 +102,7 @@ int copy_namespaces(int flags, struct taget_nsproxy (old_ns); -if (!(flags & (CLONE_NEWNS |CLONE_NEWUTS |CLONE_NEWIPC ))) +if (!(flags & (CLONE_NEWNS |CLONE_NEWUTS |CLONE_NEWIPC |CLONE_NEWUSER )))return 0 ; new_ns =clone_namespaces (old_ns);
kernel/user_namespace.c +72 -2
89 lines not on this page · raw message
Signature · 1 line
1.4.1
Re: [PATCH -mm 8/8] user ns: implement user ns unshare
kernel/user_namespace.c struct user_namespace init_user_ns = { · line 83
Quoted 13 lines · Serge E. Hallyn
From: Serge E. Hallyn <[email protected]>
Subject: [PATCH -mm 8/8] user ns: implement user ns unshareImplement
CLONE_NEWUSERflag useable at clone/unshare.Signed-off-by Serge E. Hallyn <[email protected]>---
int
copy_user_ns(int flags, struct task_struct *tsk){kernel/user_namespace.c +1
-1-struct user_namespace *old_ns = tsk->nsproxy->user_ns; +struct user_namespace *new_ns, *old_ns = tsk->nsproxy->user_ns;int err =0 ;
^^^^^^^^^^^^
The "= 0" is superfluous here.
Quoted 11 lines
kernel/user_namespace.c +5
-1if (!old_ns)return 0 ;get_user_ns (old_ns); -return err; +if (!(flags &CLONE_NEWUSER )) +return 0 ; + err = -EPERM ; +if (!capable (CAP_SYS_ADMIN )) + goto out;
kernel/user_namespace.c struct user_namespace init_user_ns = { · line 103
Quoted 10 lines
kernel/user_namespace.c +10
-0+ err = -ENOMEM ; + new_ns =clone_user_ns (old_ns); +if (!new_ns) + goto out; + + tsk->nsproxy->user_ns = new_ns; + err =0 ; +out: +put_user_ns (old_ns); +return 0 ;
^^^^^^^^^
Should be "return err;"
Regards,
Frederik
Quoted 12 lines
}
void
free_user_ns(struct kref *kref)Signature · 7 lines
1.4.1 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH -mm 8/8] user ns: implement user ns unshare
Quoted 9 lines · Frederik Deweerdt
Quoted 7 lines · Serge E. Hallyn
From: Serge E. Hallyn <[email protected]>
Subject: [PATCH -mm 8/8] user ns: implement user ns unshareImplement
CLONE_NEWUSERflag useable at clone/unshare.Signed-off-by Serge E. Hallyn <[email protected]>---
Quoted 7 lines
Review
Quoted 5 lines
int
copy_user_ns(int flags, struct task_struct *tsk){(quoted diff) +1
-1- struct user_namespace *old_ns = tsk->nsproxy->user_ns; + struct user_namespace *new_ns, *old_ns = tsk->nsproxy->user_ns; int err = 0;^^^^^^^^^^^^The "= 0" is superfluous here.
Ah, since I set it anyway, good point.
Quoted 22 lines
Quoted 11 lines
(quoted diff) +5
-1if (!old_ns) return 0; get_user_ns(old_ns); - return err; + if (!(flags & CLONE_NEWUSER)) + return 0; + err = -EPERM; + if (!capable(CAP_SYS_ADMIN)) + goto out;Review
Quoted 10 lines
(quoted diff) +10
-0+ err = -ENOMEM; + new_ns = clone_user_ns(old_ns); + if (!new_ns) + goto out; + + tsk->nsproxy->user_ns = new_ns; + err = 0; +out: + put_user_ns(old_ns); + return 0;^^^^^^^^^
Quoted 1 line
Should be "return err;"
Yes it should.
New patch attached.
(I suppose the testcase should check for the CAP_SYS_ADMIN error case...)
Thanks for the close review!
-serge
From: Serge E. Hallyn <[email protected]>
Subject: [PATCH 8/8] user ns: implement user ns unshare
Implement CLONE_NEWUSER flag useable at clone/unshare.
Changes:
Jan 4: return the actual error value in copy_user_ns().
--- include/linux/sched.h | 1 + include/linux/user_namespace.h | 10 +++++ kernel/fork.c | 22 ++++++++++-- kernel/nsproxy.c | 2 + kernel/user_namespace.c | 74 +++++++++++++++++++++++++++++++++++++++- 5 files changed, 102 insertions(+), 7 deletions(-)
include/linux/sched.h +1 -0
@@ -26,6 +26,7 @@ #define CLONE_CHILD_SETTID 0x01000000 /*#define CLONE_STOPPED 0x02000000/* Start in stopped state */ #define CLONE_NEWUTS 0x04000000/* New utsname group? */ #define CLONE_NEWIPC 0x08000000/* New ipcs */ +#define CLONE_NEWUSER 0x10000000/* New user namespace */ /* * Scheduling policies
include/linux/user_namespace.h +10 -0
@@ -25,6 +25,7 @@ static inline struct user_namespace *get }extern int copy_user_ns (int flags,struct task_struct *tsk); +extern int unshare_user_ns (unsigned long flags,struct user_namespace **new_user);extern void free_user_ns (struct kref *kref);static inline void put_user_ns (struct user_namespace *ns)
@@ -40,6 +41,15 @@ static inline struct user_namespace *getreturn NULL ; } +static inline int unshare_user_ns (unsigned long flags, +struct user_namespace **new_user) +{ +if (flags &CLONE_NEWUSER ) +return -EINVAL ; + +return 0 ; +} +static inline int copy_user_ns (int flags,struct task_struct *tsk) {return 0 ;
kernel/fork.c +18 -4
@@ -49,6 +49,7 @@ #include <linux/cn_proc.h>#include <linux/delayacct.h> #include <linux/taskstats_kern.h> #include <linux/random.h> +#include <linux/user_namespace.h> #include <asm/pgtable.h> #include <asm/pgalloc.h>
@@ -1620,6 +1621,7 @@ asmlinkage long sys_unshare(unsigned lonstruct nsproxy *new_nsproxy =NULL , *old_nsproxy =NULL ;struct uts_namespace *uts, *new_uts =NULL ;struct ipc_namespace *ipc, *new_ipc =NULL ; +struct user_namespace *user, *new_user =NULL ;check_unshare_flags (&unshare_flags);
@@ -1627,7 +1629,7 @@ asmlinkage long sys_unshare(unsigned lon err = -EINVAL ;if (unshare_flags & ~(CLONE_THREAD |CLONE_FS |CLONE_NEWNS |CLONE_SIGHAND |CLONE_VM |CLONE_FILES |CLONE_SYSVSEM | -CLONE_NEWUTS |CLONE_NEWIPC )) +CLONE_NEWUTS |CLONE_NEWIPC |CLONE_NEWUSER )) goto bad_unshare_out;if ((err =unshare_thread (unshare_flags)))
@@ -1648,18 +1650,20 @@ asmlinkage long sys_unshare(unsigned lon goto bad_unshare_cleanup_semundo;if ((err =unshare_ipcs (unshare_flags, &new_ipc))) goto bad_unshare_cleanup_uts; +if ((err =unshare_user_ns (unshare_flags, &new_user))) + goto bad_unshare_cleanup_ipc; -if (new_ns || new_uts || new_ipc) { +if (new_ns || new_uts || new_ipc || new_user) { old_nsproxy = current->nsproxy; new_nsproxy =dup_namespaces (old_nsproxy);if (!new_nsproxy) { err = -ENOMEM ; - goto bad_unshare_cleanup_ipc; + goto bad_unshare_cleanup_user; } }if (new_fs || new_ns || new_mm || new_fd || new_ulist || - new_uts || new_ipc) { + new_uts || new_ipc || new_user) {task_lock (current);
@@ -1707,12 +1711,22 @@ asmlinkage long sys_unshare(unsigned lon new_ipc = ipc; } +if (new_user) { + user = current->nsproxy->user_ns; + current->nsproxy->user_ns = new_user; + new_user = user; + } +task_unlock (current); }if (new_nsproxy)put_nsproxy (new_nsproxy); +bad_unshare_cleanup_user: +if (new_user) +put_user_ns (new_user); + bad_unshare_cleanup_ipc:if (new_ipc)put_ipc_ns (new_ipc);
kernel/nsproxy.c +1 -1
@@ -102,7 +102,7 @@ int copy_namespaces(int flags, struct taget_nsproxy (old_ns); -if (!(flags & (CLONE_NEWNS |CLONE_NEWUTS |CLONE_NEWIPC ))) +if (!(flags & (CLONE_NEWNS |CLONE_NEWUTS |CLONE_NEWIPC |CLONE_NEWUSER )))return 0 ; new_ns =clone_namespaces (old_ns);
kernel/user_namespace.c +72 -2
88 lines not on this page · raw message
Signature · 1 line
1.4.1
Re: [PATCH -mm 8/8] user ns: implement user ns unshare
On Thu, 4 Jan 2007 13:43:51 -0600
"Serge E. Hallyn" <[email protected]> wrote:
I was just about to commit this lot then I discovered vast amounts of eight-spaces-where-there-should-be-tabs. Returned to sender for complete repair, please.
kernel/fork.c asmlinkage long sys_unshare(unsigned lon · line 1728
Quoted 4 lines
kernel/fork.c +3
-0+bad_unshare_cleanup_user: +if (new_user) +put_user_ns (new_user);
put_user_ns(NULL) is legal.
Quoted 1 line
+
for(n = 0; n < UIDHASH_SZ; ++n)
^ space here
Re: [PATCH -mm 8/8] user ns: implement user ns unshare
Quoted 3 lines · On Thu, 4 Jan 2007 14:03:16 -0800 Andrew Morton <[email protected]> wrote:
I was just about to commit this lot then I discovered vast amounts of eight-spaces-where-there-should-be-tabs. Returned to sender for complete repair, please.
actually, it was just the one function, so I fixed it up.
Re: [PATCH -mm 8/8] user ns: implement user ns unshare
In reply to Frederik DeweerdtQuoted 9 lines · Frederik Deweerdt
Quoted 7 lines · Serge E. Hallyn
From: Serge E. Hallyn <[email protected]>
Subject: [PATCH -mm 8/8] user ns: implement user ns unshareImplement
CLONE_NEWUSERflag useable at clone/unshare.Signed-off-by Serge E. Hallyn <[email protected]>---
Quoted 7 lines
kernel/user_namespace.c struct user_namespace init_user_ns = { · line 83
Quoted 5 lines
int
copy_user_ns(int flags, struct task_struct *tsk){kernel/user_namespace.c +1
-1-struct user_namespace *old_ns = tsk->nsproxy->user_ns; +struct user_namespace *new_ns, *old_ns = tsk->nsproxy->user_ns;int err =0 ;^^^^^^^^^^^^The "= 0" is superfluous here.
Umm? bss gets cleared automagically, but when did we start auto-zeroing the stack?
Re: [PATCH -mm 8/8] user ns: implement user ns unshare
Quoted 18 lines · Quoting [email protected] ([email protected]):
Quoted 9 lines · Frederik Deweerdt
Quoted 7 lines · Serge E. Hallyn
From: Serge E. Hallyn <[email protected]>
Subject: [PATCH -mm 8/8] user ns: implement user ns unshareImplement
CLONE_NEWUSERflag useable at clone/unshare.Signed-off-by Serge E. Hallyn <[email protected]>---
Quoted 7 lines
kernel/user_namespace.c struct user_namespace init_user_ns = { · line 83
Quoted 5 lines
int
copy_user_ns(int flags, struct task_struct *tsk){kernel/user_namespace.c +1
-1-struct user_namespace *old_ns = tsk->nsproxy->user_ns; +struct user_namespace *new_ns, *old_ns = tsk->nsproxy->user_ns;int err =0 ;^^^^^^^^^^^^The "= 0" is superfluous here.
Quoted 2 lines
Umm? bss gets cleared automagically, but when did we start auto-zeroing the stack?
No, no, that's what i thought he meant at first too, but I actually manually set err on all paths anyway :)
-serge
Re: [PATCH -mm 8/8] user ns: implement user ns unshare
Quoted 11 lines · Serge E. Hallyn
Quoted 7 lines · Quoting [email protected] ([email protected]):
Quoted 3 lines · Frederik Deweerdt
Quoted 1 line
int err = 0;
^^^^^^^^^^^^The "= 0" is superfluous here.
Umm? bss gets cleared automagically, but when did we start auto-zeroing the stack?
No, no, that's what i thought he meant at first too, but I actually manually set err on all paths anyway :)
Oh. So it's *really* just "superfluous until somebody changes the code"...
Re: [PATCH -mm 8/8] user ns: implement user ns unshare
Quoted 7 lines · Quoting [email protected] ([email protected]):
Quoted 6 lines · Serge E. Hallyn
Quoted 5 lines · Quoting [email protected] ([email protected]):
Quoted 3 lines · Frederik Deweerdt
Quoted 1 line
int err = 0;
^^^^^^^^^^^^The "= 0" is superfluous here.
Quoted 7 lines
Quoted 5 lines
Quoted 2 lines
Umm? bss gets cleared automagically, but when did we start auto-zeroing the stack?
No, no, that's what i thought he meant at first too, but I actually manually set err on all paths anyway :)
Oh. So it's *really* just "superfluous until somebody changes the code"...
True.
-serge
Quoted 3 lines · On Thu, 4 Jan 2007 12:06:35 -0600 "Serge E. Hallyn" <[email protected]> wrote:
This patchset adds a user namespace, which allows a process to unshare its
user_structtable, allowing for separate accounting per user namespace.
With these patches applied and with CONFIG_USER_NS=n, my selinux-enabled standard FC5 machine throws a complete fit:
[ 12.323958] EDAC MC: Ver: 2.0.1 Jan 4 2007
[ 12.357476] TCP cubic registered
[ 12.360784] NET: Registered protocol family 1
[ 12.364125] NET: Registered protocol family 17
[ 12.367761] speedstep-centrino with X86_SPEEDSTEP_CENTRINO_ACPI config is deprecated.
[ 12.367763] Use X86_ACPI_CPUFREQ (acpi-cpufreq) instead.
[ 12.374666] Using IPI Shortcut mode
[ 12.378222] Time: tsc clocksource has been installed.
[ 12.381987] Time: acpi_pm clocksource has been installed.
[ 12.386522] ACPI: (supports S0 S3 S4 S5)
[ 6.344000] Freeing unused kernel memory: 184k freed
[ 6.560000] input: PS/2 Mouse as /class/input/input1
[ 6.580000] input: AlpsPS/2 ALPS GlidePoint as /class/input/input2
[ 6.760000] Uniform Multi-Platform E-IDE driver Revision: 7.00alpha2
[ 6.764000] ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
[ 6.824000] EXT3-fs: INFO: recovery required on readonly filesystem.
[ 6.824000] EXT3-fs: write access will be enabled during recovery.
[ 10.832000] kjournald starting. Commit interval 5 seconds
[ 10.836000] EXT3-fs: recovery complete.
[ 10.840000] EXT3-fs: mounted filesystem with ordered data mode.
[ 11.852000] audit(1167940353.844:2): enforcing=1 old_enforcing=0 auid=4294967295
[ 11.948000] security: 3 users, 6 roles, 1417 types, 151 bools, 1 sens, 256 cats
[ 11.952000] security: 57 classes, 41080 rules
[ 11.956000] security: class key not defined in policy
[ 11.956000] security: class context not defined in policy
[ 11.960000] security: class dccp_socket not defined in policy
[ 11.964000] security: permission dccp_recv in class node not defined in policy
[ 11.964000] security: permission dccp_send in class node not defined in policy
[ 11.968000] security: permission dccp_recv in class netif not defined in policy
[ 11.972000] security: permission dccp_send in class netif not defined in policy
[ 11.972000] security: permission setkeycreate in class process not defined in policy
[ 11.976000] security: permission setsockcreate in class process not defined in policy
[ 11.980000] security: permission polmatch in class association not defined in policy
[ 11.980000] SELinux: Completing initialization.
[ 11.984000] SELinux: Setting up existing superblocks.
[ 12.004000] SELinux: initialized (dev sda6, type ext3), uses xattr
[ 12.204000] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[ 12.208000] SELinux: initialized (dev debugfs, type debugfs), uses genfs_contexts
[ 12.208000] SELinux: initialized (dev selinuxfs, type selinuxfs), uses genfs_contexts
[ 12.212000] SELinux: initialized (dev mqueue, type mqueue), uses transition SIDs
[ 12.216000] SELinux: initialized (dev hugetlbfs, type hugetlbfs), uses genfs_contexts
[ 12.216000] SELinux: initialized (dev devpts, type devpts), uses transition SIDs
[ 12.220000] SELinux: initialized (dev eventpollfs, type eventpollfs), uses genfs_contexts
[ 12.224000] SELinux: initialized (dev inotifyfs, type inotifyfs), uses genfs_contexts
[ 12.224000] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs
[ 12.228000] SELinux: initialized (dev futexfs, type futexfs), uses genfs_contexts
[ 12.232000] SELinux: initialized (dev pipefs, type pipefs), uses task SIDs
[ 12.232000] SELinux: initialized (dev sockfs, type sockfs), uses task SIDs
[ 12.236000] SELinux: initialized (dev proc, type proc), uses genfs_contexts
[ 12.240000] SELinux: initialized (dev bdev, type bdev), uses genfs_contexts
[ 12.240000] SELinux: initialized (dev rootfs, type rootfs), uses genfs_contexts
[ 12.244000] SELinux: initialized (dev sysfs, type sysfs), uses genfs_contexts
[ 12.260000] audit(1167940354.256:3): policy loaded auid=4294967295
[ 12.944000] SELinux: initialized (dev usbfs, type usbfs), uses genfs_contexts
[ 15.376000] audit(1167969158.994:4): avc: denied { audit_write } for pid=386 comm="hwclock" capability=29 scontext=system_u:system_r:hwclock_t:s0 tcontext=system_u:system_r:hwclock_t:s0 tclass=capability
[ 33.936000] audit(1167969177.567:2292): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir
[ 33.940000] audit(1167969177.579:2293): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir
[ 33.952000] audit(1167969177.591:2294): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir
[ 33.956000] audit(1167969177.607:2295): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir
[ 33.960000] audit(1167969177.615:2296): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir
[ 33.964000] audit(1167969177.627:2297): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir
[ 33.968000] audit(1167969177.639:2298): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir
[ 33.972000] audit(1167969177.651:2299): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir
[ 33.976000] audit(1167969177.667:2300): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir
[ 33.980000] audit(1167969177.679:2301): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir
[ 33.984000] audit(1167969177.695:2302): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir<ad infinitum>
Setting CONFIG_USER_NS=y fixes this.
Quoted 76 lines · Andrew Morton
Quoted 3 lines · On Thu, 4 Jan 2007 12:06:35 -0600 "Serge E. Hallyn" <[email protected]> wrote:
This patchset adds a user namespace, which allows a process to unshare its
user_structtable, allowing for separate accounting per user namespace.With these patches applied and with
CONFIG_USER_NS=n, my selinux-enabled standard FC5 machine throws a complete fit:[ 12.323958] EDAC MC: Ver: 2.0.1 Jan 4 2007 [ 12.357476] TCP cubic registered [ 12.360784] NET: Registered protocol family 1 [ 12.364125] NET: Registered protocol family 17 [ 12.367761] speedstep-centrino with X86_SPEEDSTEP_CENTRINO_ACPI config is deprecated. [ 12.367763] Use X86_ACPI_CPUFREQ (acpi-cpufreq) instead. [ 12.374666] Using IPI Shortcut mode [ 12.378222] Time: tsc clocksource has been installed. [ 12.381987] Time: acpi_pm clocksource has been installed. [ 12.386522] ACPI: (supports S0 S3 S4 S5) [ 6.344000] Freeing unused kernel memory: 184k freed [ 6.560000] input: PS/2 Mouse as /class/input/input1 [ 6.580000] input: AlpsPS/2 ALPS GlidePoint as /class/input/input2 [ 6.760000] Uniform Multi-Platform E-IDE driver Revision: 7.00alpha2 [ 6.764000] ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx [ 6.824000] EXT3-fs: INFO: recovery required on readonly filesystem. [ 6.824000] EXT3-fs: write access will be enabled during recovery. [ 10.832000] kjournald starting. Commit interval 5 seconds [ 10.836000] EXT3-fs: recovery complete. [ 10.840000] EXT3-fs: mounted filesystem with ordered data mode. [ 11.852000] audit(1167940353.844:2): enforcing=1 old_enforcing=0 auid=4294967295 [ 11.948000] security: 3 users, 6 roles, 1417 types, 151 bools, 1 sens, 256 cats [ 11.952000] security: 57 classes, 41080 rules [ 11.956000] security: class key not defined in policy [ 11.956000] security: class context not defined in policy [ 11.960000] security: class dccp_socket not defined in policy [ 11.964000] security: permission dccp_recv in class node not defined in policy [ 11.964000] security: permission dccp_send in class node not defined in policy [ 11.968000] security: permission dccp_recv in class netif not defined in policy [ 11.972000] security: permission dccp_send in class netif not defined in policy [ 11.972000] security: permission setkeycreate in class process not defined in policy [ 11.976000] security: permission setsockcreate in class process not defined in policy [ 11.980000] security: permission polmatch in class association not defined in policy [ 11.980000] SELinux: Completing initialization. [ 11.984000] SELinux: Setting up existing superblocks. [ 12.004000] SELinux: initialized (dev sda6, type ext3), uses xattr [ 12.204000] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs [ 12.208000] SELinux: initialized (dev debugfs, type debugfs), uses genfs_contexts [ 12.208000] SELinux: initialized (dev selinuxfs, type selinuxfs), uses genfs_contexts [ 12.212000] SELinux: initialized (dev mqueue, type mqueue), uses transition SIDs [ 12.216000] SELinux: initialized (dev hugetlbfs, type hugetlbfs), uses genfs_contexts [ 12.216000] SELinux: initialized (dev devpts, type devpts), uses transition SIDs [ 12.220000] SELinux: initialized (dev eventpollfs, type eventpollfs), uses genfs_contexts [ 12.224000] SELinux: initialized (dev inotifyfs, type inotifyfs), uses genfs_contexts [ 12.224000] SELinux: initialized (dev tmpfs, type tmpfs), uses transition SIDs [ 12.228000] SELinux: initialized (dev futexfs, type futexfs), uses genfs_contexts [ 12.232000] SELinux: initialized (dev pipefs, type pipefs), uses task SIDs [ 12.232000] SELinux: initialized (dev sockfs, type sockfs), uses task SIDs [ 12.236000] SELinux: initialized (dev proc, type proc), uses genfs_contexts [ 12.240000] SELinux: initialized (dev bdev, type bdev), uses genfs_contexts [ 12.240000] SELinux: initialized (dev rootfs, type rootfs), uses genfs_contexts [ 12.244000] SELinux: initialized (dev sysfs, type sysfs), uses genfs_contexts [ 12.260000] audit(1167940354.256:3): policy loaded auid=4294967295 [ 12.944000] SELinux: initialized (dev usbfs, type usbfs), uses genfs_contexts [ 15.376000] audit(1167969158.994:4): avc: denied { audit_write } for pid=386 comm="hwclock" capability=29 scontext=system_u:system_r:hwclock_t:s0 tcontext=system_u:system_r:hwclock_t:s0 tclass=capability [ 33.936000] audit(1167969177.567:2292): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir [ 33.940000] audit(1167969177.579:2293): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir [ 33.952000] audit(1167969177.591:2294): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir [ 33.956000] audit(1167969177.607:2295): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir [ 33.960000] audit(1167969177.615:2296): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir [ 33.964000] audit(1167969177.627:2297): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir [ 33.968000] audit(1167969177.639:2298): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir [ 33.972000] audit(1167969177.651:2299): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir [ 33.976000] audit(1167969177.667:2300): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir [ 33.980000] audit(1167969177.679:2301): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir [ 33.984000] audit(1167969177.695:2302): avc: denied { search } for pid=2141 comm="klogd" name="/" dev=tmpfs ino=1225 scontext=system_u:system_r:klogd_t:s0 tcontext=system_u:object_r:tmpfs_t:s0 tclass=dir
Quoted 4 lines
<ad infinitum>
Setting
CONFIG_USER_NS=yfixes this.
Ok, I see. The CONFIG_USER_NS split is absolutely horrible. Should really get rid of the user_ns pointers altogether when !CONFIG_USER_NS. I'll try to fix it up without putting ifdefs all over - planning to send a patch tomorrow.
thanks,
-serge
Quoted 10 lines · Serge E. Hallyn
Quoted 9 lines · Andrew Morton
Quoted 3 lines · On Thu, 4 Jan 2007 12:06:35 -0600 "Serge E. Hallyn" <[email protected]> wrote:
This patchset adds a user namespace, which allows a process to unshare its
user_structtable, allowing for separate accounting per user namespace.With these patches applied and with
CONFIG_USER_NS=n, my selinux-enabled standard FC5 machine throws a complete fit:
...
Quoted 7 lines
Quoted 2 lines
Setting
CONFIG_USER_NS=yfixes this.Ok, I see. The
CONFIG_USER_NSsplit is absolutely horrible. Should really get rid of theuser_nspointers altogether when !CONFIG_USER_NS. I'll try to fix it up without putting ifdefs all over - planning to send a patch tomorrow.
Actually it's not that bad. Following patch fixes what I believe is the underlying problem, and in any case was a definite bug.
thanks,
-serge
From: Serge E. Hallyn <[email protected]>
Subject: [PATCH 1/1] user ns: fix !CONFIG_USER_NS mount denial
Don't do user_ns permission checks when !CONFIG_USER_NS.
--- fs/namespace.c | 6 ++---- include/linux/sched.h | 8 ++++++++ include/linux/user_namespace.h | 15 +++++++++++++++ 3 files changed, 25 insertions(+), 4 deletions(-)
fs/namespace.c +2 -4
@@ -236,10 +236,8 @@ static struct vfsmount *clone_mnt(structstruct super_block *sb = old->mnt_sb;struct vfsmount *mnt; -if (!(old->mnt_flags &MNT_SHARE_NS )) { -if (old->mnt_user_ns != current->nsproxy->user_ns) -return ERR_PTR (-EPERM ); - } +if (!clone_mnt_userns_permission (old)) +return ERR_PTR (-EPERM ); mnt =alloc_vfsmnt (old->mnt_devname);
include/linux/sched.h +8 -0
@@ -1588,6 +1588,7 @@ extern int cond_resched(void);extern int cond_resched_lock (spinlock_t * lock);extern int cond_resched_softirq (void ); +#ifdef CONFIG_USER_NS /* * Check whether a task and a vfsmnt belong to the same uidns. * Since the initial namespace is exempt from these checks,
@@ -1606,6 +1607,13 @@ static inline int task_mnt_same_uidns(streturn 1 ; return 0; } +#else +static inline int task_mnt_same_uidns (struct task_struct *tsk, +struct vfsmount *mnt) +{ +return 1 ; +} +#endif /*
include/linux/user_namespace.h +15 -0
@@ -35,6 +35,16 @@ static inline void put_user_ns(struct us kref_put(&ns->kref, free_user_ns); } +static inline int clone_mnt_userns_permission (struct vfsmount *old) +{ +if (!(old->mnt_flags &MNT_SHARE_NS )) { +if (old->mnt_user_ns != current->nsproxy->user_ns) +return 0 ; + } + +return 1 ; +} +#else static inline struct user_namespace *get_user_ns (struct user_namespace *ns)
@@ -59,6 +69,11 @@ static inline int copy_user_ns(int flagsstatic inline void put_user_ns (struct user_namespace *ns) { } + +static inline int clone_mnt_userns_permission (struct vfsmount *old) +{ +return 1 ; +}#endif #endif /* _LINUX_USER_H */
Signature · 1 line
1.4.1