audit: implement container identifier

Implement the proc fs write to set the audit container identifier of a process, emitting an AUDIT_CONTAINER_ID record to document the event.

This is a write from the container orchestrator task to a proc entry of the form /proc/PID/audit_containerid where PID is the process ID of the newly created task that is to become the first task in a container, or an additional task added to a container.

The write expects up to a u64 value (unset: 18446744073709551615).

The writer must have capability CAP_AUDIT_CONTROL.

This will produce a record such as this:
type=CONTAINER_ID msg=audit(2018-06-06 12:39:29.636:26949) : op=set
opid=2209 old-contid=18446744073709551615 contid=123456 pid=628 auid=root uid=root tty=ttyS0 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 comm=bash exe=/usr/bin/bash res=yes

The "op" field indicates an initial set. The "pid" to "ses" fields are the orchestrator while the "opid" field is the object's PID, the process being "contained". Old and new audit container identifier values are given in the "contid" fields, while res indicates its success.

It is not permitted to unset or re-set the audit container identifier. A child inherits its parent's audit container identifier, but then can be set only once after.

See: https://github.com/linux-audit/audit-kernel/issues/90
See: https://github.com/linux-audit/audit-userspace/issues/51
See: https://github.com/linux-audit/audit-testsuite/issues/64
See:
https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Container-ID

Signed-off-by Richard Guy Briggs <[email protected]>

---
 fs/proc/base.c             | 37 ++++++++++++++++++++++++
 include/linux/audit.h      | 25 ++++++++++++++++
 include/uapi/linux/audit.h |  2 ++
 kernel/auditsc.c           | 71

++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 135 insertions(+)

fs/proc/base.c +34 -0

index eafa39a..318dff4 100644
@@ -1302,6 +1302,41 @@ static ssize_t proc_sessionid_read(struct file *
 file, char __user * buf, .read		= proc_sessionid_read,
 	.llseek		= generic_file_llseek,
 };
+
+static ssize_t proc_contid_write(struct file *file, const char __user
 *buf, +				   size_t count, loff_t *ppos)
+{
+	struct inode *inode = file_inode(file);
+	u64 contid;
+	int rv;
+	struct task_struct *task = get_proc_task(inode);
+
+	if (!task)
+		return -ESRCH;
+	if (*ppos != 0) {
+		/* No partial writes. */
+		put_task_struct(task);
+		return -EINVAL;
+	}
+
+	rv = kstrtou64_from_user(buf, count, 10, &contid);
+	if (rv < 0) {
+		put_task_struct(task);
+		return rv;
+	}
+
+	rv = audit_set_contid(task, contid);
+	put_task_struct(task);
+	if (rv < 0)
+		return rv;
+	return count;
+}
+
+static const struct file_operations proc_contid_operations = {
+	.write		= proc_contid_write,
+	.llseek		= generic_file_llseek,
+};
+
 #endif
 
 #ifdef CONFIG_FAULT_INJECTION

@@ -2995,6 +3030,7 @@ static int proc_pid_patch_state(struct seq_file *m,

struct pid_namespace *ns, #ifdef CONFIG_AUDITSYSCALL

fs/proc/base.c +2 -0

 	REG("loginuid",   S_IWUSR|S_IRUGO, proc_loginuid_operations),
 	REG("sessionid",  S_IRUGO, proc_sessionid_operations),
+	REG("audit_containerid", S_IWUSR, proc_contid_operations),
 #endif
 #ifdef CONFIG_FAULT_INJECTION
 	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),

@@ -3386,6 +3422,7 @@ static int proc_tid_comm_permission(struct inode
 *inode, int mask) #ifdef CONFIG_AUDITSYSCALL
 	REG("loginuid",  S_IWUSR|S_IRUGO, proc_loginuid_operations),
 	REG("sessionid",  S_IRUGO, proc_sessionid_operations),
+	REG("audit_containerid", S_IWUSR, proc_contid_operations),
 #endif
 #ifdef CONFIG_FAULT_INJECTION
 	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),

include/linux/audit.h +25 -0

index 4f824c4..497cd81 100644
@@ -219,6 +219,8 @@ static inline void audit_log_task_info(struct
 audit_buffer *ab, struct audit_task_info {
 	kuid_t			loginuid;
 	unsigned int		sessionid;
+	u64			contid;
+	bool			inherited; /* containerid inheritance */
 	struct audit_context	*ctx;
 };
 extern struct audit_task_info init_struct_audit;

@@ -331,6 +333,7 @@ static inline void audit_ptrace(struct task_struct *t)
 extern int auditsc_get_stamp(struct audit_context *ctx,
 			      struct timespec64 *t, unsigned int *serial);
 extern int audit_set_loginuid(kuid_t loginuid);
+extern int audit_set_contid(struct task_struct *tsk, u64 contid);
 
 static inline kuid_t audit_get_loginuid(struct task_struct *tsk)
 {

@@ -348,6 +351,14 @@ static inline unsigned int audit_get_sessionid(struct
 task_struct *tsk) return AUDIT_SID_UNSET;
 }
 
+static inline u64 audit_get_contid(struct task_struct *tsk)
+{
+	if (!tsk->audit)
+		return AUDIT_CID_UNSET;
+	else
+		return tsk->audit->contid;
+}
+
 extern void __audit_ipc_obj(struct kern_ipc_perm *ipcp);
 extern void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t
 gid, umode_t mode); extern void __audit_bprm(struct linux_binprm *bprm);

@@ -542,6 +553,10 @@ static inline unsigned int audit_get_sessionid(struct
 task_struct *tsk) {
 	return AUDIT_SID_UNSET;
 }
+static inline kuid_t audit_get_contid(struct task_struct *tsk)
+{
+	return AUDIT_CID_UNSET;
+}
 static inline void audit_ipc_obj(struct kern_ipc_perm *ipcp)
 { }
 static inline void audit_ipc_set_perm(unsigned long qbytes, uid_t uid,

@@ -606,6 +621,16 @@ static inline bool audit_loginuid_set(struct
 task_struct *tsk) return uid_valid(audit_get_loginuid(tsk));
 }
 
+static inline bool cid_valid(u64 contid)
+{
+	return contid != AUDIT_CID_UNSET;
+}
+
+static inline bool audit_contid_set(struct task_struct *tsk)
+{
+	return cid_valid(audit_get_contid(tsk));
+}
+
 static inline void audit_log_string(struct audit_buffer *ab, const char
 *buf) {
 	audit_log_n_string(ab, buf, strlen(buf));

include/uapi/linux/audit.h +0 -0

index 04f9bd2..c3b1aca 100644

include/uapi/linux/audit.h +0 -0

 */
 
 #define AUDIT_FIRST_USER_MSG	1100	/* Userspace messages mostly

uninteresting to kernel */ #define AUDIT_USER_AVC 1107 /* We filter this
differently */

include/uapi/linux/audit.h +1 -0

@@ -466,6 +467,7 @@ struct audit_tty_status {
 
 #define AUDIT_UID_UNSET (unsigned int)-1
 #define AUDIT_SID_UNSET ((unsigned int)-1)
+#define AUDIT_CID_UNSET ((u64)-1)
 
 /* audit_rule_data supports filter rules with both integer and string
  * fields.  It corresponds with AUDIT_ADD_RULE, AUDIT_DEL_RULE and

kernel/auditsc.c +46 -0

index 59ef7a81..611e926 100644
@@ -956,6 +956,8 @@ int audit_alloc(struct task_struct *tsk)
 		return -ENOMEM;
 	info->loginuid = audit_get_loginuid(current);
 	info->sessionid = audit_get_sessionid(current);
+	info->contid = audit_get_contid(current);
+	info->inherited = true;
 	tsk->audit = info;
 
 	if (likely(!audit_ever_enabled))

@@ -985,6 +987,8 @@ int audit_alloc(struct task_struct *tsk)
 struct audit_task_info init_struct_audit = {
 	.loginuid = INVALID_UID,
 	.sessionid = AUDIT_SID_UNSET,
+	.contid = AUDIT_CID_UNSET,
+	.inherited = true,
 	.ctx = NULL,
 };
 

@@ -2112,6 +2116,73 @@ int audit_set_loginuid(kuid_t loginuid)
 }
 
 /**
+ * audit_set_contid - set current task's audit_context contid
+ * @contid: contid value
+ *
+ * Returns 0 on success, -EPERM on permission failure.
+ *
+ * Called (set) from fs/proc/base.c::proc_contid_write().
+ */
+int audit_set_contid(struct task_struct *task, u64 contid)
+{
+	u64 oldcontid;
+	int rc = 0;
+	struct audit_buffer *ab;
+	uid_t uid;
+	struct tty_struct *tty;
+	char comm[sizeof(current->comm)];
+
+	/* Can't set if audit disabled */
+	if (!task->audit)
+		return -ENOPROTOOPT;
+	oldcontid = audit_get_contid(task);
+	/* Don't allow the audit containerid to be unset */
+	if (!cid_valid(contid))
+		rc = -EINVAL;
+	/* if we don't have caps, reject */
+	else if (!capable(CAP_AUDIT_CONTROL))
+		rc = -EPERM;
+	/* if task has children or is not single-threaded, deny */
+	else if (!list_empty(&task->children))
+		rc = -EBUSY;
+	else if (!(thread_group_leader(task) && thread_group_empty(task)))
+		rc = -EALREADY;
+	/* it is already set, and not inherited from the parent, reject */
+	else if (cid_valid(oldcontid) && !task->audit->inherited)
+		rc = -EEXIST;
+	if (!rc) {
+		task_lock(task);
+		task->audit->contid = contid;
+		task->audit->inherited = false;
+		task_unlock(task);
+	}
+
+	if (!audit_enabled)

kernel/auditsc.c +11 -0

+	audit_put_tty(tty);
+	audit_log_task_context(ab);
+	audit_log_format(ab, " comm=");
+	audit_log_untrustedstring(ab, get_task_comm(comm, current));
+	audit_log_d_path_exe(ab, current->mm);
+	audit_log_format(ab, " res=%d", !rc);
+	audit_log_end(ab);
+	return rc;
+}
+
+/**
  * __audit_mq_open - record audit data for a POSIX MQ open
  * @oflag: open flag
  * @mode: mode bits

Create a new audit record AUDIT_CONTAINER to document the audit container identifier of a process if it is present.

Called from audit_log_exit(), syscalls are covered.

A sample raw event:
type=SYSCALL msg=audit(1519924845.499:257): arch=c000003e syscall=257 success=yes exit=3 a0=ffffff9c a1=56374e1cef30 a2=241 a3=1b6 items=2 ppid=606 pid=635 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=3 comm="bash" exe="/usr/bin/bash" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key="tmpcontainerid" type=CWD msg=audit(1519924845.499:257): cwd="/root" type=PATH msg=audit(1519924845.499:257): item=0 name="/tmp/" inode=13863 dev=00:27 mode=041777 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:tmp_t:s0 nametype= PARENT cap_fp=0000000000000000 cap_fi=0000000000000000 cap_fe=0 cap_fver=0 type=PATH

msg=audit(1519924845.499:257): item=1 name="/tmp/tmpcontainerid" inode=17729 dev=00:27 mode=0100644 ouid=0 ogid=0 rdev=00:00 obj=unconfined_u:object_r:user_tmp_t:s0 nametype=CREATE cap_fp=0000000000000000 cap_fi=0000000000000000 cap_fe=0 cap_fver=0 type=PROCTITLE msg=audit(1519924845.499:257):
proctitle=62617368002D6300736C65657020313B206563686F2074657374203E202F746D 702F746D70636F6E7461696E65726964 type=CONTAINER msg=audit(1519924845.499:257): op=task contid=123458

include/linux/audit.h +3 -0

 extern int audit_log_task_context(struct audit_buffer *ab);
 extern void audit_log_task_info(struct audit_buffer *ab,
 				struct task_struct *tsk);
+extern int audit_log_contid(struct task_struct *tsk,
+				    struct audit_context *context,
+				    char *op);
 
 extern int		    audit_update_lsm_rules(void);
 

@@ -202,6 +205,10 @@ static inline int audit_log_task_context(struct

audit_buffer *ab) static inline void audit_log_task_info(struct audit_buffer *ab,

include/linux/audit.h +4 -0

 				       struct task_struct *tsk)
 { }
+static inline int audit_log_contid(struct task_struct *tsk,
+					   struct audit_context *context,
+					   char *op)
+{ }
 #define audit_enabled 0
 #endif /* CONFIG_AUDIT */

include/uapi/linux/audit.h +0 -0

index c3b1aca..469ab25 100644

include/uapi/linux/audit.h +1 -0

 #define AUDIT_KERN_MODULE	1330	/* Kernel Module events */
 #define AUDIT_FANOTIFY		1331	/* Fanotify access decision */
+#define AUDIT_CONTAINER		1332	/* Container ID */
 
 #define AUDIT_AVC		1400	/* SE Linux avc denial or grant */
 #define AUDIT_SELINUX_ERR	1401	/* Internal SE Linux Errors */

kernel/audit.c +23 -0

index e7478cb..5e150c6 100644
@@ -2048,6 +2048,29 @@ void audit_log_session_info(struct audit_buffer *ab)
 audit_log_format(ab, " auid=%u ses=%u", auid, sessionid);
 }
 
+/*
+ * audit_log_contid - report container info
+ * @tsk: task to be recorded
+ * @context: task or local context for record
+ * @op: contid string description
+ */
+int audit_log_contid(struct task_struct *tsk,
+			     struct audit_context *context, char *op)
+{
+	struct audit_buffer *ab;
+
+	if (!audit_contid_set(tsk))
+		return 0;
+	/* Generate AUDIT_CONTAINER record with container ID */
+	ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONTAINER);
+	if (!ab)
+		return -ENOMEM;
+	audit_log_format(ab, "op=%s contid=%llu",
+			 op, audit_get_contid(tsk));
+	audit_log_end(ab);
+	return 0;
+}
+
 void audit_log_key(struct audit_buffer *ab, char *key)
 {
 	audit_log_format(ab, " key=");

kernel/auditsc.c +3 -0

index 611e926..a3c946c 100644
@@ -1490,10 +1490,13 @@ static void audit_log_exit(struct audit_context
 *context, struct task_struct *ts
 
 	audit_log_proctitle(tsk, context);
 
+	audit_log_contid(tsk, context, "task");
+
 	/* Send end of event record to help user space know we are finished */
 	ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE);
 	if (ab)
 		audit_log_end(ab);
+
 	if (call_panic)
 		audit_panic("error converting sid to string");

}

Quoted 174 lines · EDT Richard Guy Briggs

Implement the proc fs write to set the audit container identifier of a process, emitting an AUDIT_CONTAINER_ID record to document the event.

This is a write from the container orchestrator task to a proc entry of the form /proc/PID/audit_containerid where PID is the process ID of the newly created task that is to become the first task in a container, or an additional task added to a container.

The write expects up to a u64 value (unset: 18446744073709551615).

The writer must have capability CAP_AUDIT_CONTROL.

This will produce a record such as this:
type=CONTAINER_ID msg=audit(2018-06-06 12:39:29.636:26949) : op=set
opid=2209 old-contid=18446744073709551615 contid=123456 pid=628 auid=root uid=root tty=ttyS0 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 comm=bash exe=/usr/bin/bash res=yes

The "op" field indicates an initial set. The "pid" to "ses" fields are the orchestrator while the "opid" field is the object's PID, the process being "contained". Old and new audit container identifier values are given in the "contid" fields, while res indicates its success.

It is not permitted to unset or re-set the audit container identifier. A child inherits its parent's audit container identifier, but then can be set only once after.

See: https://github.com/linux-audit/audit-kernel/issues/90
See: https://github.com/linux-audit/audit-userspace/issues/51
See: https://github.com/linux-audit/audit-testsuite/issues/64
See:
https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Container-ID

Signed-off-by Richard Guy Briggs <[email protected]>

---
 fs/proc/base.c             | 37 ++++++++++++++++++++++++
 include/linux/audit.h      | 25 ++++++++++++++++
 include/uapi/linux/audit.h |  2 ++
 kernel/auditsc.c           | 71

++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 135 insertions(+)

fs/proc/base.c +34 -0

index eafa39a..318dff4 100644
@@ -1302,6 +1302,41 @@ static ssize_t proc_sessionid_read(struct file *
 file, char __user * buf, .read		= proc_sessionid_read,
 	.llseek		= generic_file_llseek,
 };
+
+static ssize_t proc_contid_write(struct file *file, const char __user
 *buf, +				   size_t count, loff_t *ppos)
+{
+	struct inode *inode = file_inode(file);
+	u64 contid;
+	int rv;
+	struct task_struct *task = get_proc_task(inode);
+
+	if (!task)
+		return -ESRCH;
+	if (*ppos != 0) {
+		/* No partial writes. */
+		put_task_struct(task);
+		return -EINVAL;
+	}
+
+	rv = kstrtou64_from_user(buf, count, 10, &contid);
+	if (rv < 0) {
+		put_task_struct(task);
+		return rv;
+	}
+
+	rv = audit_set_contid(task, contid);
+	put_task_struct(task);
+	if (rv < 0)
+		return rv;
+	return count;
+}
+
+static const struct file_operations proc_contid_operations = {
+	.write		= proc_contid_write,
+	.llseek		= generic_file_llseek,
+};
+
 #endif
 
 #ifdef CONFIG_FAULT_INJECTION

@@ -2995,6 +3030,7 @@ static int proc_pid_patch_state(struct seq_file *m,

struct pid_namespace *ns, #ifdef CONFIG_AUDITSYSCALL

fs/proc/base.c +2 -0

 	REG("loginuid",   S_IWUSR|S_IRUGO, proc_loginuid_operations),
 	REG("sessionid",  S_IRUGO, proc_sessionid_operations),
+	REG("audit_containerid", S_IWUSR, proc_contid_operations),
 #endif
 #ifdef CONFIG_FAULT_INJECTION
 	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),

@@ -3386,6 +3422,7 @@ static int proc_tid_comm_permission(struct inode
 *inode, int mask) #ifdef CONFIG_AUDITSYSCALL
 	REG("loginuid",  S_IWUSR|S_IRUGO, proc_loginuid_operations),
 	REG("sessionid",  S_IRUGO, proc_sessionid_operations),
+	REG("audit_containerid", S_IWUSR, proc_contid_operations),
 #endif
 #ifdef CONFIG_FAULT_INJECTION
 	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),

include/linux/audit.h +25 -0

index 4f824c4..497cd81 100644
@@ -219,6 +219,8 @@ static inline void audit_log_task_info(struct
 audit_buffer *ab, struct audit_task_info {
 	kuid_t			loginuid;
 	unsigned int		sessionid;
+	u64			contid;
+	bool			inherited; /* containerid inheritance */
 	struct audit_context	*ctx;
 };
 extern struct audit_task_info init_struct_audit;

@@ -331,6 +333,7 @@ static inline void audit_ptrace(struct task_struct *t)
 extern int auditsc_get_stamp(struct audit_context *ctx,
 			      struct timespec64 *t, unsigned int *serial);
 extern int audit_set_loginuid(kuid_t loginuid);
+extern int audit_set_contid(struct task_struct *tsk, u64 contid);
 
 static inline kuid_t audit_get_loginuid(struct task_struct *tsk)
 {

@@ -348,6 +351,14 @@ static inline unsigned int audit_get_sessionid(struct
 task_struct *tsk) return AUDIT_SID_UNSET;
 }
 
+static inline u64 audit_get_contid(struct task_struct *tsk)
+{
+	if (!tsk->audit)
+		return AUDIT_CID_UNSET;
+	else
+		return tsk->audit->contid;
+}
+
 extern void __audit_ipc_obj(struct kern_ipc_perm *ipcp);
 extern void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t
 gid, umode_t mode); extern void __audit_bprm(struct linux_binprm *bprm);

@@ -542,6 +553,10 @@ static inline unsigned int audit_get_sessionid(struct
 task_struct *tsk) {
 	return AUDIT_SID_UNSET;
 }
+static inline kuid_t audit_get_contid(struct task_struct *tsk)
+{
+	return AUDIT_CID_UNSET;
+}
 static inline void audit_ipc_obj(struct kern_ipc_perm *ipcp)
 { }
 static inline void audit_ipc_set_perm(unsigned long qbytes, uid_t uid,

@@ -606,6 +621,16 @@ static inline bool audit_loginuid_set(struct
 task_struct *tsk) return uid_valid(audit_get_loginuid(tsk));
 }
 
+static inline bool cid_valid(u64 contid)
+{
+	return contid != AUDIT_CID_UNSET;
+}
+
+static inline bool audit_contid_set(struct task_struct *tsk)
+{
+	return cid_valid(audit_get_contid(tsk));
+}
+
 static inline void audit_log_string(struct audit_buffer *ab, const char
 *buf) {
 	audit_log_n_string(ab, buf, strlen(buf));

include/uapi/linux/audit.h +0 -0

index 04f9bd2..c3b1aca 100644

include/uapi/linux/audit.h line 74

Quoted 4 lines

include/uapi/linux/audit.h +1 -0

@@ -71,6 +71,7 @@
 #define AUDIT_TTY_SET		1017	/* Set TTY auditing status */
 #define AUDIT_SET_FEATURE	1018	/* Turn an audit feature on or off */
 #define AUDIT_GET_FEATURE	1019	/* Get which features are enabled */
+#define AUDIT_CONTAINER_ID	1020	/* Define the container id and 

information

Quoted 81 lines

include/uapi/linux/audit.h +0 -0

 */
 
 #define AUDIT_FIRST_USER_MSG	1100	/* Userspace messages mostly

uninteresting to kernel */ #define AUDIT_USER_AVC 1107 /* We filter this
differently */

include/uapi/linux/audit.h +1 -0

@@ -466,6 +467,7 @@ struct audit_tty_status {
 
 #define AUDIT_UID_UNSET (unsigned int)-1
 #define AUDIT_SID_UNSET ((unsigned int)-1)
+#define AUDIT_CID_UNSET ((u64)-1)
 
 /* audit_rule_data supports filter rules with both integer and string
  * fields.  It corresponds with AUDIT_ADD_RULE, AUDIT_DEL_RULE and

kernel/auditsc.c +46 -0

index 59ef7a81..611e926 100644
@@ -956,6 +956,8 @@ int audit_alloc(struct task_struct *tsk)
 		return -ENOMEM;
 	info->loginuid = audit_get_loginuid(current);
 	info->sessionid = audit_get_sessionid(current);
+	info->contid = audit_get_contid(current);
+	info->inherited = true;
 	tsk->audit = info;
 
 	if (likely(!audit_ever_enabled))

@@ -985,6 +987,8 @@ int audit_alloc(struct task_struct *tsk)
 struct audit_task_info init_struct_audit = {
 	.loginuid = INVALID_UID,
 	.sessionid = AUDIT_SID_UNSET,
+	.contid = AUDIT_CID_UNSET,
+	.inherited = true,
 	.ctx = NULL,
 };
 

@@ -2112,6 +2116,73 @@ int audit_set_loginuid(kuid_t loginuid)
 }
 
 /**
+ * audit_set_contid - set current task's audit_context contid
+ * @contid: contid value
+ *
+ * Returns 0 on success, -EPERM on permission failure.
+ *
+ * Called (set) from fs/proc/base.c::proc_contid_write().
+ */
+int audit_set_contid(struct task_struct *task, u64 contid)
+{
+	u64 oldcontid;
+	int rc = 0;
+	struct audit_buffer *ab;
+	uid_t uid;
+	struct tty_struct *tty;
+	char comm[sizeof(current->comm)];
+
+	/* Can't set if audit disabled */
+	if (!task->audit)
+		return -ENOPROTOOPT;
+	oldcontid = audit_get_contid(task);
+	/* Don't allow the audit containerid to be unset */
+	if (!cid_valid(contid))
+		rc = -EINVAL;
+	/* if we don't have caps, reject */
+	else if (!capable(CAP_AUDIT_CONTROL))
+		rc = -EPERM;
+	/* if task has children or is not single-threaded, deny */
+	else if (!list_empty(&task->children))
+		rc = -EBUSY;
+	else if (!(thread_group_leader(task) && thread_group_empty(task)))
+		rc = -EALREADY;
+	/* it is already set, and not inherited from the parent, reject */
+	else if (cid_valid(oldcontid) && !task->audit->inherited)
+		rc = -EEXIST;
+	if (!rc) {
+		task_lock(task);
+		task->audit->contid = contid;
+		task->audit->inherited = false;
+		task_unlock(task);
+	}
+
+	if (!audit_enabled)

kernel/auditsc.c int audit_set_loginuid(kuid_t loginuid) · line 2170

Quoted 10 lines

kernel/auditsc.c +9 -0

+		return rc;
+
+	ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONTAINER_ID);
+	if (!ab)
+		return rc;
+
+	uid = from_kuid(&init_user_ns, task_uid(current));
+	tty = audit_get_tty(current);
+	audit_log_format(ab, "op=set opid=%d old-contid=%llu contid=%llu pid=%d
 uid=%u auid=%u tty=%s ses=%u", +			 task_tgid_nr(task), oldcontid, 

contid,

kernel/auditsc.c int audit_set_loginuid(kuid_t loginuid) · line 2174

Quoted 4 lines

kernel/auditsc.c +4 -0

+			 task_tgid_nr(current), uid
+			 from_kuid(&init_user_ns, audit_get_loginuid(current)),
+			 tty ? tty_name(tty) : "(none)",
+			 audit_get_sessionid(current));

The event code doesn't match the example event at the top. (uid and auid are transposed.) But the code looks right.

Ack for the event format.

-Steve

Quoted 4 lines

kernel/auditsc.c +4 -0

+	audit_put_tty(tty);
+	audit_log_task_context(ab);
+	audit_log_format(ab, " comm=");
+	audit_log_untrustedstring(ab, get_task_comm(comm, current));

kernel/auditsc.c int audit_set_loginuid(kuid_t loginuid) · line 2188

Quoted 10 lines

kernel/auditsc.c +7 -0

+	audit_log_d_path_exe(ab, current->mm);
+	audit_log_format(ab, " res=%d", !rc);
+	audit_log_end(ab);
+	return rc;
+}
+
+/**
  * __audit_mq_open - record audit data for a POSIX MQ open
  * @oflag: open flag
  * @mode: mode bits

Implement kernel audit container identifier.

Quoted 1 line · Richard Guy Briggs

Implement kernel audit container identifier.

What tree does this series build upon as a base? I don't seem to find one with the necessary base patches applied.

    Stefan

Signed-off-by Richard Guy Briggs <[email protected]>

---
 net/rfkill/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

net/rfkill/core.c +1 -2

index 59d0eb9..e89a009 100644
@@ -494,7 +494,7 @@ void rfkill_remove_epo_lock(void)
 /**
  * rfkill_is_epo_lock_active - returns true EPO is active
  *
- * Returns 0 (false) if there is NOT an active EPO contidion,
+ * Returns 0 (false) if there is NOT an active EPO condition,
  * and 1 (true) if there is an active EPO contition, which
  * locks all radios in one of the BLOCKED states.
  *
--

1.8.3.1

Quoted 5 lines · Stefan Berger

Quoted 1 line · Richard Guy Briggs

Implement kernel audit container identifier.

What tree does this series build upon as a base? I don't seem to find one with the necessary base patches applied.

It is Paul Moore's audit next tree, with patch ("collect audit task parameters") of ghak81:

        git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit.git
        https://www.redhat.com/archives/linux-audit/2018-May/msg00091.html
        https://www.redhat.com/archives/linux-audit/2018-May/msg00100.html

Implement the proc fs write to set the audit container identifier of a process, emitting an AUDIT_CONTAINER_ID record to document the event.

This is a write from the container orchestrator task to a proc entry of the form /proc/PID/audit_containerid where PID is the process ID of the newly created task that is to become the first task in a container, or an additional task added to a container.

The write expects up to a u64 value (unset: 18446744073709551615).

The writer must have capability CAP_AUDIT_CONTROL.

This will produce a record such as this:
type=CONTAINER_ID msg=audit(2018-06-06 12:39:29.636:26949) : op=set opid=2209 old-contid=18446744073709551615 contid=123456 pid=628 auid=root uid=root tty=ttyS0 ses=1 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 comm=bash exe=/usr/bin/bash res=yes

The "op" field indicates an initial set. The "pid" to "ses" fields are the orchestrator while the "opid" field is the object's PID, the process being "contained". Old and new audit container identifier values are given in the "contid" fields, while res indicates its success.

It is not permitted to unset or re-set the audit container identifier. A child inherits its parent's audit container identifier, but then can be set only once after.

See: https://github.com/linux-audit/audit-kernel/issues/90
See: https://github.com/linux-audit/audit-userspace/issues/51
See: https://github.com/linux-audit/audit-testsuite/issues/64
See: https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Container-ID

Signed-off-by Richard Guy Briggs <[email protected]>

---
 fs/proc/base.c             | 37 ++++++++++++++++++++++++
 include/linux/audit.h      | 25 ++++++++++++++++
 include/uapi/linux/audit.h |  2 ++
 kernel/auditsc.c           | 71 ++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 135 insertions(+)

include/linux/audit.h +0 -0

@@ -606,6 +621,16 @@ static inline bool audit_loginuid_set(struct task_struct *tsk)
       return uid_valid(audit_get_loginuid(tsk));
 }

kernel/auditsc.c +21 -0

        tsk->audit = info;
 
        if (likely(!audit_ever_enabled))

@@ -985,6 +987,8 @@ int audit_alloc(struct task_struct *tsk)
 struct audit_task_info init_struct_audit = {
        .loginuid = INVALID_UID,
        .sessionid = AUDIT_SID_UNSET,
+       .contid = AUDIT_CID_UNSET,
+       .inherited = true,
        .ctx = NULL,
 };
 

@@ -2112,6 +2116,73 @@ int audit_set_loginuid(kuid_t loginuid)
 }
 
 /**
+ * audit_set_contid - set current task's audit_context contid
+ * @contid: contid value
+ *
+ * Returns 0 on success, -EPERM on permission failure.
+ *
+ * Called (set) from fs/proc/base.c::proc_contid_write().
+ */
+int audit_set_contid(struct task_struct *task, u64 contid)
+{
+       u64 oldcontid;
+       int rc = 0;
+       struct audit_buffer *ab;
+       uid_t uid;
+       struct tty_struct *tty;
+       char comm[sizeof(current->comm)];
+
+       /* Can't set if audit disabled */
+       if (!task->audit)
+               return -ENOPROTOOPT;

kernel/auditsc.c +21 -0

+       }
+
+       if (!audit_enabled)
+               return rc;
+
+       ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONTAINER_ID);
+       if (!ab)
+               return rc;
+
+       uid = from_kuid(&init_user_ns, task_uid(current));
+       tty = audit_get_tty(current);
+       audit_log_format(ab, "op=set opid=%d old-contid=%llu contid=%llu pid=%d uid=%u auid=%u tty=%s ses=%u",
+                        task_tgid_nr(task), oldcontid, contid,
+                        task_tgid_nr(current), uid
+                        from_kuid(&init_user_ns, audit_get_loginuid(current)),
+                        tty ? tty_name(tty) : "(none)",
+                        audit_get_sessionid(current));
+       audit_put_tty(tty);
+       audit_log_task_context(ab);
+       audit_log_format(ab, " comm=");
+       audit_log_untrustedstring(ab, get_task_comm(comm, current));

Create a new audit record AUDIT_CONTAINER to document the audit container identifier of a process if it is present.

Called from audit_log_exit(), syscalls are covered.

A sample raw event:
type=SYSCALL msg=audit(1519924845.499:257): arch=c000003e syscall=257 success=yes exit=3 a0=ffffff9c a1=56374e1cef30 a2=241 a3=1b6 items=2 ppid=606 pid=635 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=3 comm="bash" exe="/usr/bin/bash" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key="tmpcontainerid" type=CWD msg=audit(1519924845.499:257): cwd="/root"
type=PATH msg=audit(1519924845.499:257): item=0 name="/tmp/" inode=13863 dev=00:27 mode=041777 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:tmp_t:s0 nametype= PARENT cap_fp=0000000000000000 cap_fi=0000000000000000 cap_fe=0 cap_fver=0
type=PATH msg=audit(1519924845.499:257): item=1 name="/tmp/tmpcontainerid" inode=17729 dev=00:27 mode=0100644 ouid=0 ogid=0 rdev=00:00 obj=unconfined_u:object_r:user_tmp_t:s0 nametype=CREATE cap_fp=0000000000000000 cap_fi=0000000000000000 cap_fe=0 cap_fver=0
type=PROCTITLE msg=audit(1519924845.499:257): proctitle=62617368002D6300736C65657020313B206563686F2074657374203E202F746D702F746D70636F6E7461696E65726964
type=CONTAINER msg=audit(1519924845.499:257): op=task contid=123458

See: https://github.com/linux-audit/audit-kernel/issues/90
See: https://github.com/linux-audit/audit-userspace/issues/51
See: https://github.com/linux-audit/audit-testsuite/issues/64
See: https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Container-ID

Signed-off-by Richard Guy Briggs <[email protected]>

---
 include/linux/audit.h      |  7 +++++++
 include/uapi/linux/audit.h |  1 +
 kernel/audit.c             | 23 +++++++++++++++++++++++
 kernel/auditsc.c           |  3 +++
 4 files changed, 34 insertions(+)

include/uapi/linux/audit.h +0 -0

 #define AUDIT_AVC              1400    /* SE Linux avc denial or grant */
 #define AUDIT_SELINUX_ERR      1401    /* Internal SE Linux Errors */

kernel/audit.c +9 -0

index e7478cb..5e150c6 100644
@@ -2048,6 +2048,29 @@ void audit_log_session_info(struct audit_buffer *ab)
        audit_log_format(ab, " auid=%u ses=%u", auid, sessionid);
 }
 
+/*
+ * audit_log_contid - report container info
+ * @tsk: task to be recorded
+ * @context: task or local context for record
+ * @op: contid string description
+ */
+int audit_log_contid(struct task_struct *tsk,
+                            struct audit_context *context, char *op)
+{

Add audit container identifier support to ptrace and signals. In particular, the "op" field provides a way to label the auxiliary record to which it is associated.

Signed-off-by Richard Guy Briggs <[email protected]>

---
 include/linux/audit.h | 11 +++++------
 kernel/audit.c        | 13 +++++++------
 kernel/audit.h        |  2 ++
 kernel/auditsc.c      | 21 ++++++++++++++++-----
 4 files changed, 30 insertions(+), 17 deletions(-)

kernel/audit.c +6 -4

index 5e150c6..ba304a8 100644
@@ -142,6 +142,7 @@ struct audit_net {
 kuid_t         audit_sig_uid = INVALID_UID;
 pid_t          audit_sig_pid = -1;
 u32            audit_sig_sid = 0;
+u64            audit_sig_cid = AUDIT_CID_UNSET;
 
 /* Records can be lost in several ways:
    0) [suppressed in audit_alloc]

@@ -1437,6 +1438,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                        memcpy(sig_data->ctx, ctx, len);
                        security_release_secctx(ctx, len);
                }
+               sig_data->cid = audit_sig_cid;
                audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
                                 sig_data, sizeof(*sig_data) + len);
                kfree(sig_data);

@@ -2050,23 +2052,22 @@ void audit_log_session_info(struct audit_buffer *ab)
 
 /*
  * audit_log_contid - report container info
- * @tsk: task to be recorded
  * @context: task or local context for record
  * @op: contid string description
+ * @contid: container ID to report
  */
-int audit_log_contid(struct task_struct *tsk,
-                            struct audit_context *context, char *op)
+int audit_log_contid(struct audit_context *context,
+                             char *op, u64 contid)
 {
        struct audit_buffer *ab;
 
-       if (!audit_contid_set(tsk))
+       if (!cid_valid(contid))
                return 0;

Standalone audit records have the timestamp and serial number generated on the fly and as such are unique, making them standalone. This new function audit_alloc_local() generates a local audit context that will be used only for a standalone record and its auxiliary record(s). The context is discarded immediately after the local associated records are produced.

Signed-off-by Richard Guy Briggs <[email protected]>

---
 include/linux/audit.h |  8 ++++++++
 kernel/auditsc.c      | 25 +++++++++++++++++++++++--
 2 files changed, 31 insertions(+), 2 deletions(-)

kernel/auditsc.c +7 -1

+       return context;
+}
+
+void audit_free_context(struct audit_context *context)
+{
+       if (!context)
+               return;
        audit_free_names(context);
        unroll_tree_refs(context, NULL, 0);
        free_tree_refs(context);
--

1.8.3.1

--
Linux-audit mailing list
[email protected]
https://www.redhat.com/mailman/listinfo/linux-audit

Add audit container identifier auxiliary record to tty logging rule event standalone records.

Signed-off-by Richard Guy Briggs <[email protected]>

---
 drivers/tty/tty_audit.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

drivers/tty/tty_audit.c +0 -0

index e30aa6b..66bd850 100644

drivers/tty/tty_audit.c +3 -1

-       ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_TTY);
+       ab = audit_log_start(context, GFP_KERNEL, AUDIT_TTY);
        if (ab) {
                char name[sizeof(tsk->comm)];
 

@@ -80,6 +81,8 @@ static void tty_audit_log(const char *description, dev_t dev,
                audit_log_n_hex(ab, data, size);
                audit_log_end(ab);
        }
+       audit_log_contid(context, "tty", audit_get_contid(tsk));
+       audit_free_context(context);
 }

Implement audit container identifier filtering using the AUDIT_CONTID field name to send an 8-character string representing a u64 since the value field is only u32.

Sending it as two u32 was considered, but gathering and comparing two fields was more complex.

The feature indicator is AUDIT_FEATURE_BITMAP_CONTAINERID_FILTER.

See: https://github.com/linux-audit/audit-kernel/issues/91
See: https://github.com/linux-audit/audit-userspace/issues/40
See: https://github.com/linux-audit/audit-testsuite/issues/64
See: https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Container-ID

Signed-off-by Richard Guy Briggs <[email protected]>

---
 include/linux/audit.h      |  1 +
 include/uapi/linux/audit.h |  5 ++++-
 kernel/audit.h             |  1 +
 kernel/auditfilter.c       | 47 ++++++++++++++++++++++++++++++++++++++++++++++
 kernel/auditsc.c           |  3 +++
 5 files changed, 56 insertions(+), 1 deletion(-)

include/linux/audit.h +1 -0

index f549121..1e37abf 100644
@@ -76,6 +76,7 @@ struct audit_field {
        u32                             type;
        union {
                u32                     val;
+               u64                     val64;
                kuid_t                  uid;
                kgid_t                  gid;
                struct {

include/uapi/linux/audit.h +4 -1

index 469ab25..b440558 100644
@@ -262,6 +262,7 @@
 #define AUDIT_LOGINUID_SET     24
 #define AUDIT_SESSIONID        25      /* Session ID */
 #define AUDIT_FSTYPE   26      /* FileSystem Type */
+#define AUDIT_CONTID   27      /* Container ID */
 
                                /* These are ONLY useful when checking
                                 * at syscall exit time (AUDIT_AT_EXIT). */

@@ -342,6 +343,7 @@ enum {
 #define AUDIT_FEATURE_BITMAP_SESSIONID_FILTER  0x00000010
 #define AUDIT_FEATURE_BITMAP_LOST_RESET                0x00000020
 #define AUDIT_FEATURE_BITMAP_FILTER_FS         0x00000040
+#define AUDIT_FEATURE_BITMAP_CONTAINERID_FILTER        0x00000080
 
 #define AUDIT_FEATURE_BITMAP_ALL (AUDIT_FEATURE_BITMAP_BACKLOG_LIMIT | \
                                  AUDIT_FEATURE_BITMAP_BACKLOG_WAIT_TIME | \

@@ -349,7 +351,8 @@ enum {
                                  AUDIT_FEATURE_BITMAP_EXCLUDE_EXTEND | \
                                  AUDIT_FEATURE_BITMAP_SESSIONID_FILTER | \
                                  AUDIT_FEATURE_BITMAP_LOST_RESET | \
-                                 AUDIT_FEATURE_BITMAP_FILTER_FS)
+                                 AUDIT_FEATURE_BITMAP_FILTER_FS | \
+                                 AUDIT_FEATURE_BITMAP_CONTAINERID_FILTER)
 
 /* deprecated: AUDIT_VERSION_* */
 #define AUDIT_VERSION_LATEST           AUDIT_FEATURE_BITMAP_ALL

kernel/audit.h +1 -0

index 1cf1c35..743d445 100644
@@ -235,6 +235,7 @@ static inline int audit_hash_ino(u32 ino)
 
 extern int audit_match_class(int class, unsigned syscall);
 extern int audit_comparator(const u32 left, const u32 op, const u32 right);
+extern int audit_comparator64(const u64 left, const u32 op, const u64 right);
 extern int audit_uid_comparator(kuid_t left, u32 op, kuid_t right);
 extern int audit_gid_comparator(kgid_t left, u32 op, kgid_t right);
 extern int parent_len(const char *path);

kernel/auditfilter.c +47 -0

index eaa3201..a5f60ce 100644
@@ -410,6 +410,7 @@ static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
        /* FALL THROUGH */
        case AUDIT_ARCH:
        case AUDIT_FSTYPE:
+       case AUDIT_CONTID:
                if (f->op != Audit_not_equal && f->op != Audit_equal)
                        return -EINVAL;
                break;

@@ -584,6 +585,14 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
                        }
                        entry->rule.exe = audit_mark;
                        break;
+               case AUDIT_CONTID:
+                       if (f->val != sizeof(u64))
+                               goto exit_free;
+                       str = audit_unpack_string(&bufp, &remain, f->val);
+                       if (IS_ERR(str))
+                               goto exit_free;
+                       f->val64 = ((u64 *)str)[0];
+                       break;
                }
        }
 

@@ -666,6 +675,11 @@ static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
                        data->buflen += data->values[i] =
                                audit_pack_string(&bufp, audit_mark_path(krule->exe));
                        break;
+               case AUDIT_CONTID:
+                       data->buflen += data->values[i] = sizeof(u64);
+                       for (i = 0; i < sizeof(u64); i++)
+                               ((char *)bufp)[i] = ((char *)&f->val64)[i];
+                       break;
                case AUDIT_LOGINUID_SET:
                        if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
                                data->fields[i] = AUDIT_LOGINUID;

@@ -752,6 +766,10 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
                        if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
                                return 1;
                        break;
+               case AUDIT_CONTID:
+                       if (a->fields[i].val64 != b->fields[i].val64)
+                               return 1;
+                       break;
                default:
                        if (a->fields[i].val != b->fields[i].val)
                                return 1;

@@ -1208,6 +1226,31 @@ int audit_comparator(u32 left, u32 op, u32 right)
        }
 }
 
+int audit_comparator64(u64 left, u32 op, u64 right)
+{
+       switch (op) {
+       case Audit_equal:
+               return (left == right);
+       case Audit_not_equal:
+               return (left != right);
+       case Audit_lt:
+               return (left < right);
+       case Audit_le:
+               return (left <= right);
+       case Audit_gt:
+               return (left > right);
+       case Audit_ge:
+               return (left >= right);
+       case Audit_bitmask:
+               return (left & right);
+       case Audit_bittest:
+               return ((left & right) == right);
+       default:
+               BUG();
+               return 0;
+       }
+}
+
 int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
 {
        switch (op) {

@@ -1346,6 +1389,10 @@ int audit_filter(int msgtype, unsigned int listtype)
                                result = audit_comparator(audit_loginuid_set(current),
                                                          f->op, f->val);
                                break;
+                       case AUDIT_CONTID:
+                               result = audit_comparator64(audit_get_contid(current),
+                                                             f->op, f->val64);
+                               break;
                        case AUDIT_MSGTYPE:
                                result = audit_comparator(msgtype, f->op, f->val);
                                break;

kernel/auditsc.c +3 -1

index 81c9765..ea1ee35 100644
@@ -622,6 +622,9 @@ static int audit_filter_rules(struct task_struct *tsk,
                case AUDIT_LOGINUID_SET:
                        result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val);
                        break;
+               case AUDIT_CONTID:
+                       result = audit_comparator64(audit_get_contid(tsk), f->op, f->val64);
+                       break;
                case AUDIT_SUBJ_USER:
                case AUDIT_SUBJ_ROLE:
                case AUDIT_SUBJ_TYPE:
--

1.8.3.1

--
Linux-audit mailing list
[email protected]
https://www.redhat.com/mailman/listinfo/linux-audit

Audit events could happen in a network namespace outside of a task context due to packets received from the net that trigger an auditing rule prior to being associated with a running task. The network namespace could in use by multiple containers by association to the tasks in that network namespace. We still want a way to attribute these events to any potential containers. Keep a list per network namespace to track these audit container identifiiers.

Add/increment the audit container identifier on:
- initial setting of the audit container identifier via /proc
- clone/fork call that inherits an audit container identifier
- unshare call that inherits an audit container identifier
- setns call that inherits an audit container identifier Delete/decrement the audit container identifier on:
- an inherited audit container identifier dropped when child set
- process exit
- unshare call that drops a net namespace
- setns call that drops a net namespace

See: https://github.com/linux-audit/audit-kernel/issues/92
See: https://github.com/linux-audit/audit-testsuite/issues/64
See: https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Container-ID

Signed-off-by Richard Guy Briggs <[email protected]>

---
 include/linux/audit.h | 23 ++++++++++++++++
 kernel/audit.c        | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++
 kernel/auditsc.c      |  5 ++++
 kernel/nsproxy.c      |  4 +++
 4 files changed, 104 insertions(+)

include/linux/audit.h +7 -0

+static inline void audit_contid_add(struct net *net, u64 contid)
+{ }
+static inline void audit_contid_del(struct net *net, u64 contid)
+{ }
+static inline void audit_switch_task_namespaces(struct nsproxy *ns, struct task_struct *p)
+{ }
+
 #define audit_enabled 0
 #endif /* CONFIG_AUDIT */
 

kernel/audit.c +19 -0

index ba304a8..ecd2de4 100644
@@ -106,6 +106,7 @@
  */
 struct audit_net {
        struct sock *sk;
+       struct list_head contid_list;
 };
 
 /**

@@ -311,6 +312,76 @@ static struct sock *audit_get_sk(const struct net *net)
        return aunet->sk;
 }
 
+/**
+ * audit_get_contid_list - Return the audit container ID list for the given network namespace
+ * @net: the destination network namespace
+ *
+ * Description:
+ * Returns the list pointer if valid, NULL otherwise.  The caller must ensure
+ * that a reference is held for the network namespace while the sock is in use.
+ */
+struct list_head *audit_get_contid_list(const struct net *net)
+{
+       struct audit_net *aunet = net_generic(net, audit_net_id);
+
+       return &aunet->contid_list;
+}
+
+void audit_contid_add(struct net *net, u64 contid)
+{
+       struct list_head *contid_list = audit_get_contid_list(net);

kernel/audit.c +12 -0

+       cont = kmalloc(sizeof(struct audit_contid), GFP_KERNEL);
+       if (!cont)
+               return;
+       INIT_LIST_HEAD(&cont->list);
+       cont->id = contid;
+       refcount_set(&cont->refcount, 1);
+       list_add(&cont->list, contid_list);
+}
+
+void audit_contid_del(struct net *net, u64 contid)
+{
+       struct list_head *contid_list = audit_get_contid_list(net);

kernel/audit.c +14 -0

+}
 
+void audit_switch_task_namespaces(struct nsproxy *ns, struct task_struct *p)
+{
+       u64 contid = audit_get_contid(p);
+       struct nsproxy *new = p->nsproxy;
+
+       if (!cid_valid(contid))
+               return;
+       audit_contid_del(ns->net_ns, contid);
+       if (new)
+               audit_contid_add(new->net_ns, contid);
+}
+
 void audit_panic(const char *message)
 {
        switch (audit_failure) {

@@ -1550,6 +1621,7 @@ static int __net_init audit_net_init(struct net *net)
                return -ENOMEM;
        }
        aunet->sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
+       INIT_LIST_HEAD(&aunet->contid_list);
 
        return 0;
 }

kernel/auditsc.c +5 -0

index ea1ee35..6ab5e5e 100644
@@ -75,6 +75,7 @@
 #include <linux/uaccess.h>
 #include <linux/fsnotify_backend.h>
 #include <uapi/linux/limits.h>
+#include <net/net_namespace.h>
 
 #include "audit.h"
 

@@ -2165,6 +2166,7 @@ int audit_set_contid(struct task_struct *task, u64 contid)
        uid_t uid;
        struct tty_struct *tty;
        char comm[sizeof(current->comm)];
+       struct net *net = task->nsproxy->net_ns;
 
        /* Can't set if audit disabled */
        if (!task->audit)

@@ -2185,10 +2187,13 @@ int audit_set_contid(struct task_struct *task, u64 contid)
        else if (cid_valid(oldcontid) && !task->audit->inherited)
                rc = -EEXIST;
        if (!rc) {
+               if (cid_valid(oldcontid))
+                       audit_contid_del(net, oldcontid);
                task_lock(task);
                task->audit->contid = contid;
                task->audit->inherited = false;
                task_unlock(task);
+               audit_contid_add(net, contid);
        }
 
        if (!audit_enabled)

kernel/nsproxy.c +4 -1

index f6c5d33..dcb69fe 100644
@@ -27,6 +27,7 @@
 #include <linux/syscalls.h>
 #include <linux/cgroup.h>
 #include <linux/perf_event.h>
+#include <linux/audit.h>
 
 static struct kmem_cache *nsproxy_cachep;
 

@@ -140,6 +141,7 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk)
        struct nsproxy *old_ns = tsk->nsproxy;
        struct user_namespace *user_ns = task_cred_xxx(tsk, user_ns);
        struct nsproxy *new_ns;
+       u64 contid = audit_get_contid(tsk);
 
        if (likely(!(flags & (CLONE_NEWNS | CLONE_NEWUTS | CLONE_NEWIPC |
                              CLONE_NEWPID | CLONE_NEWNET |

@@ -167,6 +169,7 @@ int copy_namespaces(unsigned long flags, struct task_struct *tsk)
                return  PTR_ERR(new_ns);
 
        tsk->nsproxy = new_ns;
+       audit_contid_add(new_ns->net_ns, contid);
        return 0;
 }
 

@@ -224,6 +227,7 @@ void switch_task_namespaces(struct task_struct *p, struct nsproxy *new)
        ns = p->nsproxy;
        p->nsproxy = new;
        task_unlock(p);
+       audit_switch_task_namespaces(ns, p);
 
        if (ns && atomic_dec_and_test(&ns->count))
                free_nsproxy(ns);
--

1.8.3.1

--
Linux-audit mailing list
[email protected]
https://www.redhat.com/mailman/listinfo/linux-audit

Add audit container identifier auxiliary record(s) to NETFILTER_PKT event standalone records. Iterate through all potential audit container identifiers associated with a network namespace.

Signed-off-by Richard Guy Briggs <[email protected]>

---
 include/linux/audit.h    |  5 +++++
 kernel/audit.c           | 20 +++++++++++++++++++-
 kernel/auditsc.c         |  2 ++
 net/netfilter/xt_AUDIT.c | 12 ++++++++++--
 4 files changed, 36 insertions(+), 3 deletions(-)

include/linux/audit.h +3 -0

 extern int                 audit_update_lsm_rules(void);
 

@@ -231,6 +233,9 @@ static inline void audit_contid_del(struct net *net, u64 contid)
 { }
 static inline void audit_switch_task_namespaces(struct nsproxy *ns, struct task_struct *p)
 { }
+static inline void audit_log_contid_list(struct net *net,
+                                       struct audit_context *context)
+{ }
 
 #define audit_enabled 0
 #endif /* CONFIG_AUDIT */

kernel/audit.c +0 -0

index ecd2de4..8cca41a 100644
@@ -382,6 +382,20 @@ void audit_switch_task_namespaces(struct nsproxy *ns, struct task_struct *p)
                audit_contid_add(new->net_ns, contid);
 }
 

kernel/audit.c +4 -0

+       }
+}
+EXPORT_SYMBOL(audit_log_contid_list);
+
 void audit_panic(const char *message)
 {
        switch (audit_failure) {

kernel/auditsc.c +0 -0

 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
                                 kuid_t auid, kuid_t uid, unsigned int sessionid,

net/netfilter/xt_AUDIT.c +10 -3

index f368ee6..10d2707 100644
@@ -71,10 +71,13 @@ static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb)
 {
        struct audit_buffer *ab;
        int fam = -1;
+       struct audit_context *context;
+       struct net *net;
 
        if (audit_enabled == 0)
-               goto errout;
-       ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
+               goto out;
+       context = audit_alloc_local();
+       ab = audit_log_start(context, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
        if (ab == NULL)
                goto errout;
 

@@ -104,7 +107,12 @@ static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb)
 
        audit_log_end(ab);
 
+       net = xt_net(par);
+       audit_log_contid_list(net, context);
+
 errout:
+       audit_free_context(context);
+out:
        return XT_CONTINUE;
 }
 
--

1.8.3.1

--
Linux-audit mailing list
[email protected]
https://www.redhat.com/mailman/listinfo/linux-audit

Add support for reading the audit container identifier from the proc filesystem.

This is a read from the proc entry of the form /proc/PID/audit_containerid where PID is the process ID of the task whose audit container identifier is sought.

The read expects up to a u64 value (unset: 18446744073709551615).

Signed-off-by Richard Guy Briggs <[email protected]>

---
 fs/proc/base.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

fs/proc/base.c +4 -0

index 318dff4..ca8bfe2 100644
@@ -1303,6 +1303,21 @@ static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
        .llseek         = generic_file_llseek,
 };
 
+static ssize_t proc_contid_read(struct file *file, char __user *buf,
+                                 size_t count, loff_t *ppos)
+{
+       struct inode *inode = file_inode(file);

fs/proc/base.c +3 -2

 static ssize_t proc_contid_write(struct file *file, const char __user *buf,
                                   size_t count, loff_t *ppos)
 {

@@ -1333,6 +1348,7 @@ static ssize_t proc_contid_write(struct file *file, const char __user *buf,
 }
 
 static const struct file_operations proc_contid_operations = {
+       .read           = proc_contid_read,
        .write          = proc_contid_write,
        .llseek         = generic_file_llseek,
 };

@@ -3030,7 +3046,7 @@ static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
 #ifdef CONFIG_AUDITSYSCALL
        REG("loginuid",   S_IWUSR|S_IRUGO, proc_loginuid_operations),
        REG("sessionid",  S_IRUGO, proc_sessionid_operations),
-       REG("audit_containerid", S_IWUSR, proc_contid_operations),
+       REG("audit_containerid", S_IWUSR|S_IRUSR, proc_contid_operations),
 #endif
 #ifdef CONFIG_FAULT_INJECTION
        REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),

@@ -3422,7 +3438,7 @@ static int proc_tid_comm_permission(struct inode *inode, int mask)
 #ifdef CONFIG_AUDITSYSCALL
        REG("loginuid",  S_IWUSR|S_IRUGO, proc_loginuid_operations),
        REG("sessionid",  S_IRUGO, proc_sessionid_operations),
-       REG("audit_containerid", S_IWUSR, proc_contid_operations),
+       REG("audit_containerid", S_IWUSR|S_IRUSR, proc_contid_operations),
 #endif
 #ifdef CONFIG_FAULT_INJECTION
        REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),

Add audit container identifier auxiliary record(s) to NETFILTER_PKT event standalone records. Iterate through all potential audit container identifiers associated with a network namespace.

Signed-off-by Richard Guy Briggs <[email protected]>

---
 include/linux/audit.h    |  5 +++++
 kernel/audit.c           | 20 +++++++++++++++++++-
 kernel/auditsc.c         |  2 ++
 net/netfilter/xt_AUDIT.c | 12 ++++++++++--
 4 files changed, 36 insertions(+), 3 deletions(-)

include/linux/audit.h +5 -0

index 7e2e51c..4560a4e 100644
@@ -167,6 +167,8 @@ extern int audit_log_contid(struct audit_context *context,
 extern void audit_contid_add(struct net *net, u64 contid);
 extern void audit_contid_del(struct net *net, u64 contid);
 extern void audit_switch_task_namespaces(struct nsproxy *ns, struct task_struct *p);
+extern void audit_log_contid_list(struct net *net,
+                                struct audit_context *context);
 
 extern int                 audit_update_lsm_rules(void);
 

@@ -231,6 +233,9 @@ static inline void audit_contid_del(struct net *net, u64 contid)
 { }
 static inline void audit_switch_task_namespaces(struct nsproxy *ns, struct task_struct *p)
 { }
+static inline void audit_log_contid_list(struct net *net,
+                                       struct audit_context *context)
+{ }
 
 #define audit_enabled 0
 #endif /* CONFIG_AUDIT */

kernel/audit.c +19 -1

index ecd2de4..8cca41a 100644
@@ -382,6 +382,20 @@ void audit_switch_task_namespaces(struct nsproxy *ns, struct task_struct *p)
                audit_contid_add(new->net_ns, contid);
 }
 
+void audit_log_contid_list(struct net *net, struct audit_context *context)
+{
+       struct audit_contid *cont;
+       int i = 0;
+
+       list_for_each_entry(cont, audit_get_contid_list(net), list) {
+               char buf[14];
+
+               sprintf(buf, "net%u", i++);
+               audit_log_contid(context, buf, cont->id);
+       }
+}
+EXPORT_SYMBOL(audit_log_contid_list);
+
 void audit_panic(const char *message)
 {
        switch (audit_failure) {

@@ -2132,17 +2146,21 @@ int audit_log_contid(struct audit_context *context,
                              char *op, u64 contid)
 {
        struct audit_buffer *ab;
+       gfp_t gfpflags;
 
        if (!cid_valid(contid))
                return 0;
+       /* We can be called in atomic context via audit_tg() */
+       gfpflags = (in_atomic() || irqs_disabled()) ? GFP_ATOMIC : GFP_KERNEL;
        /* Generate AUDIT_CONTAINER record with container ID */
-       ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONTAINER);
+       ab = audit_log_start(context, gfpflags, AUDIT_CONTAINER);
        if (!ab)
                return -ENOMEM;
        audit_log_format(ab, "op=%s contid=%llu", op, contid);
        audit_log_end(ab);
        return 0;
 }
+EXPORT_SYMBOL(audit_log_contid);
 
 void audit_log_key(struct audit_buffer *ab, char *key)
 {

kernel/auditsc.c +2 -0

index 6ab5e5e..e2a16d2 100644
@@ -1015,6 +1015,7 @@ struct audit_context *audit_alloc_local(void)
        context->in_syscall = 1;
        return context;
 }
+EXPORT_SYMBOL(audit_alloc_local);
 
 void audit_free_context(struct audit_context *context)
 {

@@ -1029,6 +1030,7 @@ void audit_free_context(struct audit_context *context)
        audit_proctitle_free(context);
        kfree(context);
 }
+EXPORT_SYMBOL(audit_free_context);
 
 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
                                 kuid_t auid, kuid_t uid, unsigned int sessionid,

net/netfilter/xt_AUDIT.c +10 -3

index f368ee6..10d2707 100644
@@ -71,10 +71,13 @@ static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb)
 {
        struct audit_buffer *ab;
        int fam = -1;
+       struct audit_context *context;
+       struct net *net;
 
        if (audit_enabled == 0)
-               goto errout;
-       ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
+               goto out;
+       context = audit_alloc_local();
+       ab = audit_log_start(context, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
        if (ab == NULL)
                goto errout;
 

@@ -104,7 +107,12 @@ static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb)
 
        audit_log_end(ab);
 
+       net = xt_net(par);
+       audit_log_contid_list(net, context);
+
 errout:
+       audit_free_context(context);
+out:
        return XT_CONTINUE;
 }
 
--

1.8.3.1

Quoted 26 lines · Richard Guy Briggs

Add support for reading the audit container identifier from the proc filesystem.

This is a read from the proc entry of the form /proc/PID/audit_containerid where PID is the process ID of the task whose audit container identifier is sought.

The read expects up to a u64 value (unset: 18446744073709551615).

Signed-off-by Richard Guy Briggs <[email protected]>

---
 fs/proc/base.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

fs/proc/base.c +4 -0

index 318dff4..ca8bfe2 100644
@@ -1303,6 +1303,21 @@ static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
        .llseek         = generic_file_llseek,
 };
 
+static ssize_t proc_contid_read(struct file *file, char __user *buf,
+                                 size_t count, loff_t *ppos)
+{
+       struct inode *inode = file_inode(file);

fs/proc/base.c static ssize_t proc_sessionid_read(struct file * file, char __user * buf, · line 1319

Quoted 10 lines

fs/proc/base.c +10 -0

+       struct task_struct *task = get_proc_task(inode);
+       ssize_t length;
+       char tmpbuf[TMPBUFLEN*2];
+
+       if (!task)
+               return -ESRCH;
+       length = scnprintf(tmpbuf, TMPBUFLEN*2, "%llu", audit_get_contid(task));
+       put_task_struct(task);
+       return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
+}

While I still remain very nervous about opening the audit container ID up for abuse by making it accessible, I understand that this would make things a lot easier us (e.g. testing) and perhaps the container engines as well. In order to limit the potential for abuse, what do you think about restricting read access to those processes which have CAP_AUDIT_CONTROL, similar to what we do for setting the audit container ID?

Quoted 25 lines

fs/proc/base.c +2 -2

 static ssize_t proc_contid_write(struct file *file, const char __user *buf,
                                   size_t count, loff_t *ppos)
 {

@@ -1333,6 +1348,7 @@ static ssize_t proc_contid_write(struct file *file, const char __user *buf,
 }
 
 static const struct file_operations proc_contid_operations = {
+       .read           = proc_contid_read,
        .write          = proc_contid_write,
        .llseek         = generic_file_llseek,
 };

@@ -3030,7 +3046,7 @@ static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
 #ifdef CONFIG_AUDITSYSCALL
        REG("loginuid",   S_IWUSR|S_IRUGO, proc_loginuid_operations),
        REG("sessionid",  S_IRUGO, proc_sessionid_operations),
-       REG("audit_containerid", S_IWUSR, proc_contid_operations),
+       REG("audit_containerid", S_IWUSR|S_IRUSR, proc_contid_operations),
 #endif
 #ifdef CONFIG_FAULT_INJECTION
        REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),

@@ -3422,7 +3438,7 @@ static int proc_tid_comm_permission(struct inode *inode, int mask)
 #ifdef CONFIG_AUDITSYSCALL
        REG("loginuid",  S_IWUSR|S_IRUGO, proc_loginuid_operations),
        REG("sessionid",  S_IRUGO, proc_sessionid_operations),
-       REG("audit_containerid", S_IWUSR, proc_contid_operations),