SELinux: display SELinux mount options in /proc/mounts

Where's 1/2? I've ported this to the tip of the vfs-2.6 tree, but can't compile it without the other half.

Miklos

----
From: Eric Paris <[email protected]>

This patch causes SELinux mount options to show up in /proc/mounts. As with other code in the area seq_put errors are ignored. Other LSM's will not have their mount options displayed until they fill in their own security_sb_show_options() function.

Signed-off-by Eric Paris <[email protected]>

Signed-off-by Miklos Szeredi <[email protected]>

---
 fs/namespace.c           |   12 ++++++----
 include/linux/security.h |    9 ++++++++
 security/dummy.c         |    6 +++++
 security/security.c      |    5 ++++
 security/selinux/hooks.c |   52 +++++++++++++++++++++++++++++++++++++++++++++--
 5 files changed, 77 insertions(+), 7 deletions(-)

Index: vfs-2.6/include/linux/security.h
===================================================================

include/linux/security.h +9 -0

@@ -74,6 +74,7 @@ struct xfrm_selector;
 struct xfrm_policy;
 struct xfrm_state;
 struct xfrm_user_sec_ctx;
+struct seq_file;
 
 extern int cap_netlink_send(struct sock *sk, struct sk_buff *skb);
 extern int cap_netlink_recv(struct sk_buff *skb, int cap);

@@ -1259,6 +1260,7 @@ struct security_operations {
 	void (*sb_free_security) (struct super_block * sb);
 	int (*sb_copy_data)(char *orig, char *copy);
 	int (*sb_kern_mount) (struct super_block *sb, void *data);
+	int (*sb_show_options) (struct seq_file *m, struct super_block *sb);
 	int (*sb_statfs) (struct dentry *dentry);
 	int (*sb_mount) (char *dev_name, struct path *path,
 			 char *type, unsigned long flags, void *data);

@@ -1527,6 +1529,7 @@ int security_sb_alloc(struct super_block
 void security_sb_free(struct super_block *sb);
 int security_sb_copy_data(char *orig, char *copy);
 int security_sb_kern_mount(struct super_block *sb, void *data);
+int security_sb_show_options(struct seq_file *m, struct super_block *sb);
 int security_sb_statfs(struct dentry *dentry);
 int security_sb_mount(char *dev_name, struct path *path,
                        char *type, unsigned long flags, void *data);

@@ -1800,6 +1803,12 @@ static inline int security_sb_kern_mount
 	return 0;
 }
 
+static inline int security_sb_show_options(struct seq_file *m,
+					   struct super_block *sb)
+{
+	return 0;
+}
+
 static inline int security_sb_statfs (struct dentry *dentry)
 {
 	return 0;

Index: vfs-2.6/security/dummy.c
===================================================================

security/dummy.c +6 -0

@@ -191,6 +191,11 @@ static int dummy_sb_kern_mount (struct s
 	return 0;
 }
 
+static int dummy_sb_show_options(struct seq_file *m, struct super_block *sb)
+{
+	return 0;
+}
+
 static int dummy_sb_statfs (struct dentry *dentry)
 {
 	return 0;

@@ -1017,6 +1022,7 @@ void security_fixup_ops (struct security
 	set_to_dummy_if_null(ops, sb_free_security);
 	set_to_dummy_if_null(ops, sb_copy_data);
 	set_to_dummy_if_null(ops, sb_kern_mount);
+	set_to_dummy_if_null(ops, sb_show_options);
 	set_to_dummy_if_null(ops, sb_statfs);
 	set_to_dummy_if_null(ops, sb_mount);
 	set_to_dummy_if_null(ops, sb_check_sb);

Index: vfs-2.6/security/security.c
===================================================================

security/security.c +5 -0

@@ -255,6 +255,11 @@ int security_sb_kern_mount(struct super_
 	return security_ops->sb_kern_mount(sb, data);
 }
 
+int security_sb_show_options(struct seq_file *m, struct super_block *sb)
+{
+	return security_ops->sb_show_options(m, sb);
+}
+
 int security_sb_statfs(struct dentry *dentry)
 {
 	return security_ops->sb_statfs(dentry);

Index: vfs-2.6/security/selinux/hooks.c
===================================================================

security/selinux/hooks.c +50 -2

@@ -9,7 +9,8 @@
  *            James Morris <[email protected]>
  *
  *  Copyright (C) 2001,2002 Networks Associates Technology, Inc.
- *  Copyright (C) 2003 Red Hat, Inc., James Morris <[email protected]>
+ *  Copyright (C) 2003-2008 Red Hat, Inc., James Morris <[email protected]>
+ *					   Eric Paris <[email protected]>
  *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
  *                          <[email protected]>
  *  Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.

@@ -19,7 +20,7 @@
  *
  *	This program is free software; you can redistribute it and/or modify
  *	it under the terms of the GNU General Public License version 2,
- *      as published by the Free Software Foundation.
+ *	as published by the Free Software Foundation.
  */
 
 #include <linux/init.h>

@@ -947,6 +948,52 @@ out_err:
 	return rc;
 }
 
+void selinux_write_opts(struct seq_file *m, struct security_mnt_opts *opts)
+{
+	int i;
+	char *prefix;
+
+	for (i = 0; i < opts->num_mnt_opts; i++) {
+		/* we need a comma before each option */
+		seq_putc(m, ',');
+
+		switch (opts->mnt_opts_flags[i]) {
+		case CONTEXT_MNT:
+			prefix = CONTEXT_STR;
+			break;
+		case FSCONTEXT_MNT:
+			prefix = FSCONTEXT_STR;
+			break;
+		case ROOTCONTEXT_MNT:
+			prefix = ROOTCONTEXT_STR;
+			break;
+		case DEFCONTEXT_MNT:
+			prefix = DEFCONTEXT_STR;
+			break;
+		default:
+			BUG();
+		};
+		seq_puts(m, prefix);
+		seq_puts(m, opts->mnt_opts[i]);
+	}
+}
+
+static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
+{
+	struct security_mnt_opts opts;
+	int rc;
+
+	rc = selinux_get_mnt_opts(sb, &opts);
+	if (rc)
+		return rc;
+
+	selinux_write_opts(m, &opts);
+
+	security_free_mnt_opts(&opts);
+
+	return rc;
+}
+
 static inline u16 inode_mode_to_security_class(umode_t mode)
 {
 	switch (mode & S_IFMT) {

@@ -5257,6 +5304,7 @@ static struct security_operations selinu
 	.sb_free_security =		selinux_sb_free_security,
 	.sb_copy_data =			selinux_sb_copy_data,
 	.sb_kern_mount =	        selinux_sb_kern_mount,
+	.sb_show_options =		selinux_sb_show_options,
 	.sb_statfs =			selinux_sb_statfs,
 	.sb_mount =			selinux_mount,
 	.sb_umount =			selinux_umount,

Index: vfs-2.6/fs/namespace.c
===================================================================

fs/namespace.c +7 -5

@@ -748,7 +748,7 @@ struct proc_fs_info {
 	const char *str;
 };
 
-static void show_sb_opts(struct seq_file *m, struct super_block *sb)
+static int show_sb_opts(struct seq_file *m, struct super_block *sb)
 {
 	static const struct proc_fs_info fs_info[] = {
 		{ MS_SYNCHRONOUS, ",sync" },

@@ -762,6 +762,8 @@ static void show_sb_opts(struct seq_file
 		if (sb->s_flags & fs_infop->flag)
 			seq_puts(m, fs_infop->str);
 	}
+
+	return security_sb_show_options(m, sb);
 }
 
 static void show_mnt_opts(struct seq_file *m, struct vfsmount *mnt)

@@ -804,9 +806,9 @@ static int show_vfsmnt(struct seq_file *
 	seq_putc(m, ' ');
 	show_type(m, mnt->mnt_sb);
 	seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw");
-	show_sb_opts(m, mnt->mnt_sb);
+	err = show_sb_opts(m, mnt->mnt_sb);
 	show_mnt_opts(m, mnt);
-	if (mnt->mnt_sb->s_op->show_options)
+	if (!err && mnt->mnt_sb->s_op->show_options)
 		err = mnt->mnt_sb->s_op->show_options(m, mnt);
 	seq_puts(m, " 0 0\n");
 	return err;

@@ -863,8 +865,8 @@ static int show_mountinfo(struct seq_fil
 	seq_putc(m, ' ');
 	mangle(m, mnt->mnt_devname ? mnt->mnt_devname : "none");
 	seq_puts(m, sb->s_flags & MS_RDONLY ? " ro" : " rw");
-	show_sb_opts(m, sb);
-	if (sb->s_op->show_options)
+	err = show_sb_opts(m, sb);
+	if (!err && sb->s_op->show_options)
 		err = sb->s_op->show_options(m, mnt);
 	seq_putc(m, '\n');
 	return err;

Where's 1/2? I've ported this to the tip of the vfs-2.6 tree, but can't compile it without the other half.

Miklos

----
From: Eric Paris <[email protected]>

This patch causes SELinux mount options to show up in /proc/mounts. As with other code in the area seq_put errors are ignored. Other LSM's will not have their mount options displayed until they fill in their own security_sb_show_options() function.

Signed-off-by Eric Paris <[email protected]>

Signed-off-by Miklos Szeredi <[email protected]>

---
 fs/namespace.c           |   12 ++++++----
 include/linux/security.h |    9 ++++++++
 security/dummy.c         |    6 +++++
 security/security.c      |    5 ++++
 security/selinux/hooks.c |   52 +++++++++++++++++++++++++++++++++++++++++++++--
 5 files changed, 77 insertions(+), 7 deletions(-)

Index: vfs-2.6/include/linux/security.h
===================================================================

include/linux/security.h +9 -0

@@ -74,6 +74,7 @@ struct xfrm_selector;
 struct xfrm_policy;
 struct xfrm_state;
 struct xfrm_user_sec_ctx;
+struct seq_file;
 
 extern int cap_netlink_send(struct sock *sk, struct sk_buff *skb);
 extern int cap_netlink_recv(struct sk_buff *skb, int cap);

@@ -1259,6 +1260,7 @@ struct security_operations {
 	void (*sb_free_security) (struct super_block * sb);
 	int (*sb_copy_data)(char *orig, char *copy);
 	int (*sb_kern_mount) (struct super_block *sb, void *data);
+	int (*sb_show_options) (struct seq_file *m, struct super_block *sb);
 	int (*sb_statfs) (struct dentry *dentry);
 	int (*sb_mount) (char *dev_name, struct path *path,
 			 char *type, unsigned long flags, void *data);

@@ -1527,6 +1529,7 @@ int security_sb_alloc(struct super_block
 void security_sb_free(struct super_block *sb);
 int security_sb_copy_data(char *orig, char *copy);
 int security_sb_kern_mount(struct super_block *sb, void *data);
+int security_sb_show_options(struct seq_file *m, struct super_block *sb);
 int security_sb_statfs(struct dentry *dentry);
 int security_sb_mount(char *dev_name, struct path *path,
                        char *type, unsigned long flags, void *data);

@@ -1800,6 +1803,12 @@ static inline int security_sb_kern_mount
 	return 0;
 }
 
+static inline int security_sb_show_options(struct seq_file *m,
+					   struct super_block *sb)
+{
+	return 0;
+}
+
 static inline int security_sb_statfs (struct dentry *dentry)
 {
 	return 0;

Index: vfs-2.6/security/dummy.c
===================================================================

security/dummy.c +6 -0

@@ -191,6 +191,11 @@ static int dummy_sb_kern_mount (struct s
 	return 0;
 }
 
+static int dummy_sb_show_options(struct seq_file *m, struct super_block *sb)
+{
+	return 0;
+}
+
 static int dummy_sb_statfs (struct dentry *dentry)
 {
 	return 0;

@@ -1017,6 +1022,7 @@ void security_fixup_ops (struct security
 	set_to_dummy_if_null(ops, sb_free_security);
 	set_to_dummy_if_null(ops, sb_copy_data);
 	set_to_dummy_if_null(ops, sb_kern_mount);
+	set_to_dummy_if_null(ops, sb_show_options);
 	set_to_dummy_if_null(ops, sb_statfs);
 	set_to_dummy_if_null(ops, sb_mount);
 	set_to_dummy_if_null(ops, sb_check_sb);

Index: vfs-2.6/security/security.c
===================================================================

security/security.c +5 -0

@@ -255,6 +255,11 @@ int security_sb_kern_mount(struct super_
 	return security_ops->sb_kern_mount(sb, data);
 }
 
+int security_sb_show_options(struct seq_file *m, struct super_block *sb)
+{
+	return security_ops->sb_show_options(m, sb);
+}
+
 int security_sb_statfs(struct dentry *dentry)
 {
 	return security_ops->sb_statfs(dentry);

Index: vfs-2.6/security/selinux/hooks.c
===================================================================

security/selinux/hooks.c +50 -2

@@ -9,7 +9,8 @@
  *            James Morris <[email protected]>
  *
  *  Copyright (C) 2001,2002 Networks Associates Technology, Inc.
- *  Copyright (C) 2003 Red Hat, Inc., James Morris <[email protected]>
+ *  Copyright (C) 2003-2008 Red Hat, Inc., James Morris <[email protected]>
+ *					   Eric Paris <[email protected]>
  *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
  *                          <[email protected]>
  *  Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.

@@ -19,7 +20,7 @@
  *
  *	This program is free software; you can redistribute it and/or modify
  *	it under the terms of the GNU General Public License version 2,
- *      as published by the Free Software Foundation.
+ *	as published by the Free Software Foundation.
  */
 
 #include <linux/init.h>

@@ -947,6 +948,52 @@ out_err:
 	return rc;
 }
 
+void selinux_write_opts(struct seq_file *m, struct security_mnt_opts *opts)
+{
+	int i;
+	char *prefix;
+
+	for (i = 0; i < opts->num_mnt_opts; i++) {
+		/* we need a comma before each option */
+		seq_putc(m, ',');
+
+		switch (opts->mnt_opts_flags[i]) {
+		case CONTEXT_MNT:
+			prefix = CONTEXT_STR;
+			break;
+		case FSCONTEXT_MNT:
+			prefix = FSCONTEXT_STR;
+			break;
+		case ROOTCONTEXT_MNT:
+			prefix = ROOTCONTEXT_STR;
+			break;
+		case DEFCONTEXT_MNT:
+			prefix = DEFCONTEXT_STR;
+			break;
+		default:
+			BUG();
+		};
+		seq_puts(m, prefix);
+		seq_puts(m, opts->mnt_opts[i]);
+	}
+}
+
+static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
+{
+	struct security_mnt_opts opts;
+	int rc;
+
+	rc = selinux_get_mnt_opts(sb, &opts);
+	if (rc)
+		return rc;
+
+	selinux_write_opts(m, &opts);
+
+	security_free_mnt_opts(&opts);
+
+	return rc;
+}
+
 static inline u16 inode_mode_to_security_class(umode_t mode)
 {
 	switch (mode & S_IFMT) {

@@ -5257,6 +5304,7 @@ static struct security_operations selinu
 	.sb_free_security =		selinux_sb_free_security,
 	.sb_copy_data =			selinux_sb_copy_data,
 	.sb_kern_mount =	        selinux_sb_kern_mount,
+	.sb_show_options =		selinux_sb_show_options,
 	.sb_statfs =			selinux_sb_statfs,
 	.sb_mount =			selinux_mount,
 	.sb_umount =			selinux_umount,

Index: vfs-2.6/fs/namespace.c
===================================================================

fs/namespace.c +7 -5

@@ -748,7 +748,7 @@ struct proc_fs_info {
 	const char *str;
 };
 
-static void show_sb_opts(struct seq_file *m, struct super_block *sb)
+static int show_sb_opts(struct seq_file *m, struct super_block *sb)
 {
 	static const struct proc_fs_info fs_info[] = {
 		{ MS_SYNCHRONOUS, ",sync" },

@@ -762,6 +762,8 @@ static void show_sb_opts(struct seq_file
 		if (sb->s_flags & fs_infop->flag)
 			seq_puts(m, fs_infop->str);
 	}
+
+	return security_sb_show_options(m, sb);
 }
 
 static void show_mnt_opts(struct seq_file *m, struct vfsmount *mnt)

@@ -804,9 +806,9 @@ static int show_vfsmnt(struct seq_file *
 	seq_putc(m, ' ');
 	show_type(m, mnt->mnt_sb);
 	seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw");
-	show_sb_opts(m, mnt->mnt_sb);
+	err = show_sb_opts(m, mnt->mnt_sb);
 	show_mnt_opts(m, mnt);
-	if (mnt->mnt_sb->s_op->show_options)
+	if (!err && mnt->mnt_sb->s_op->show_options)
 		err = mnt->mnt_sb->s_op->show_options(m, mnt);
 	seq_puts(m, " 0 0\n");
 	return err;

@@ -863,8 +865,8 @@ static int show_mountinfo(struct seq_fil
 	seq_putc(m, ' ');
 	mangle(m, mnt->mnt_devname ? mnt->mnt_devname : "none");
 	seq_puts(m, sb->s_flags & MS_RDONLY ? " ro" : " rw");
-	show_sb_opts(m, sb);
-	if (sb->s_op->show_options)
+	err = show_sb_opts(m, sb);
+	if (!err && sb->s_op->show_options)
 		err = sb->s_op->show_options(m, mnt);
 	seq_putc(m, '\n');
 	return err;

Quoted 2 lines · Miklos Szeredi

Where's 1/2? I've ported this to the tip of the vfs-2.6 tree, but can't compile it without the other half.

I have a question for everyone though. How are these options used? SELinux mount options can contain commas. When sending such options from userspace they are inside quotes. Should I go ahead and quote selinux options so they can be directly used back into mount commands? Should I just leave them in there without quotes and let anyone who tries to feel them back into mount figure it out?

I'm ignoring seq_* failures. Which kinda scares me since it means i could get half of one option and half of another and the user would not realize it. Maybe I should build a single string for each selinux option and do a single seq_puts() so seq_* failure only means missing options, not possibly corrupted options...

Quoted 232 lines

Miklos

----
From: Eric Paris <[email protected]>

This patch causes SELinux mount options to show up in /proc/mounts. As with other code in the area seq_put errors are ignored. Other LSM's will not have their mount options displayed until they fill in their own security_sb_show_options() function.

Signed-off-by Eric Paris <[email protected]>

Signed-off-by Miklos Szeredi <[email protected]>

---
 fs/namespace.c           |   12 ++++++----
 include/linux/security.h |    9 ++++++++
 security/dummy.c         |    6 +++++
 security/security.c      |    5 ++++
 security/selinux/hooks.c |   52 +++++++++++++++++++++++++++++++++++++++++++++--
 5 files changed, 77 insertions(+), 7 deletions(-)

Index: vfs-2.6/include/linux/security.h
===================================================================

include/linux/security.h +9 -0

@@ -74,6 +74,7 @@ struct xfrm_selector;
 struct xfrm_policy;
 struct xfrm_state;
 struct xfrm_user_sec_ctx;
+struct seq_file;
 
 extern int cap_netlink_send(struct sock *sk, struct sk_buff *skb);
 extern int cap_netlink_recv(struct sk_buff *skb, int cap);

@@ -1259,6 +1260,7 @@ struct security_operations {
 	void (*sb_free_security) (struct super_block * sb);
 	int (*sb_copy_data)(char *orig, char *copy);
 	int (*sb_kern_mount) (struct super_block *sb, void *data);
+	int (*sb_show_options) (struct seq_file *m, struct super_block *sb);
 	int (*sb_statfs) (struct dentry *dentry);
 	int (*sb_mount) (char *dev_name, struct path *path,
 			 char *type, unsigned long flags, void *data);

@@ -1527,6 +1529,7 @@ int security_sb_alloc(struct super_block
 void security_sb_free(struct super_block *sb);
 int security_sb_copy_data(char *orig, char *copy);
 int security_sb_kern_mount(struct super_block *sb, void *data);
+int security_sb_show_options(struct seq_file *m, struct super_block *sb);
 int security_sb_statfs(struct dentry *dentry);
 int security_sb_mount(char *dev_name, struct path *path,
                        char *type, unsigned long flags, void *data);

@@ -1800,6 +1803,12 @@ static inline int security_sb_kern_mount
 	return 0;
 }
 
+static inline int security_sb_show_options(struct seq_file *m,
+					   struct super_block *sb)
+{
+	return 0;
+}
+
 static inline int security_sb_statfs (struct dentry *dentry)
 {
 	return 0;

Index: vfs-2.6/security/dummy.c
===================================================================

security/dummy.c +6 -0

@@ -191,6 +191,11 @@ static int dummy_sb_kern_mount (struct s
 	return 0;
 }
 
+static int dummy_sb_show_options(struct seq_file *m, struct super_block *sb)
+{
+	return 0;
+}
+
 static int dummy_sb_statfs (struct dentry *dentry)
 {
 	return 0;

@@ -1017,6 +1022,7 @@ void security_fixup_ops (struct security
 	set_to_dummy_if_null(ops, sb_free_security);
 	set_to_dummy_if_null(ops, sb_copy_data);
 	set_to_dummy_if_null(ops, sb_kern_mount);
+	set_to_dummy_if_null(ops, sb_show_options);
 	set_to_dummy_if_null(ops, sb_statfs);
 	set_to_dummy_if_null(ops, sb_mount);
 	set_to_dummy_if_null(ops, sb_check_sb);

Index: vfs-2.6/security/security.c
===================================================================

security/security.c +5 -0

@@ -255,6 +255,11 @@ int security_sb_kern_mount(struct super_
 	return security_ops->sb_kern_mount(sb, data);
 }
 
+int security_sb_show_options(struct seq_file *m, struct super_block *sb)
+{
+	return security_ops->sb_show_options(m, sb);
+}
+
 int security_sb_statfs(struct dentry *dentry)
 {
 	return security_ops->sb_statfs(dentry);

Index: vfs-2.6/security/selinux/hooks.c
===================================================================

security/selinux/hooks.c +50 -2

@@ -9,7 +9,8 @@
  *            James Morris <[email protected]>
  *
  *  Copyright (C) 2001,2002 Networks Associates Technology, Inc.
- *  Copyright (C) 2003 Red Hat, Inc., James Morris <[email protected]>
+ *  Copyright (C) 2003-2008 Red Hat, Inc., James Morris <[email protected]>
+ *					   Eric Paris <[email protected]>
  *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
  *                          <[email protected]>
  *  Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.

@@ -19,7 +20,7 @@
  *
  *	This program is free software; you can redistribute it and/or modify
  *	it under the terms of the GNU General Public License version 2,
- *      as published by the Free Software Foundation.
+ *	as published by the Free Software Foundation.
  */
 
 #include <linux/init.h>

@@ -947,6 +948,52 @@ out_err:
 	return rc;
 }
 
+void selinux_write_opts(struct seq_file *m, struct security_mnt_opts *opts)
+{
+	int i;
+	char *prefix;
+
+	for (i = 0; i < opts->num_mnt_opts; i++) {
+		/* we need a comma before each option */
+		seq_putc(m, ',');
+
+		switch (opts->mnt_opts_flags[i]) {
+		case CONTEXT_MNT:
+			prefix = CONTEXT_STR;
+			break;
+		case FSCONTEXT_MNT:
+			prefix = FSCONTEXT_STR;
+			break;
+		case ROOTCONTEXT_MNT:
+			prefix = ROOTCONTEXT_STR;
+			break;
+		case DEFCONTEXT_MNT:
+			prefix = DEFCONTEXT_STR;
+			break;
+		default:
+			BUG();
+		};
+		seq_puts(m, prefix);
+		seq_puts(m, opts->mnt_opts[i]);
+	}
+}
+
+static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
+{
+	struct security_mnt_opts opts;
+	int rc;
+
+	rc = selinux_get_mnt_opts(sb, &opts);
+	if (rc)
+		return rc;
+
+	selinux_write_opts(m, &opts);
+
+	security_free_mnt_opts(&opts);
+
+	return rc;
+}
+
 static inline u16 inode_mode_to_security_class(umode_t mode)
 {
 	switch (mode & S_IFMT) {

@@ -5257,6 +5304,7 @@ static struct security_operations selinu
 	.sb_free_security =		selinux_sb_free_security,
 	.sb_copy_data =			selinux_sb_copy_data,
 	.sb_kern_mount =	        selinux_sb_kern_mount,
+	.sb_show_options =		selinux_sb_show_options,
 	.sb_statfs =			selinux_sb_statfs,
 	.sb_mount =			selinux_mount,
 	.sb_umount =			selinux_umount,

Index: vfs-2.6/fs/namespace.c
===================================================================

fs/namespace.c +7 -5

@@ -748,7 +748,7 @@ struct proc_fs_info {
 	const char *str;
 };
 
-static void show_sb_opts(struct seq_file *m, struct super_block *sb)
+static int show_sb_opts(struct seq_file *m, struct super_block *sb)
 {
 	static const struct proc_fs_info fs_info[] = {
 		{ MS_SYNCHRONOUS, ",sync" },

@@ -762,6 +762,8 @@ static void show_sb_opts(struct seq_file
 		if (sb->s_flags & fs_infop->flag)
 			seq_puts(m, fs_infop->str);
 	}
+
+	return security_sb_show_options(m, sb);
 }
 
 static void show_mnt_opts(struct seq_file *m, struct vfsmount *mnt)

@@ -804,9 +806,9 @@ static int show_vfsmnt(struct seq_file *
 	seq_putc(m, ' ');
 	show_type(m, mnt->mnt_sb);
 	seq_puts(m, __mnt_is_readonly(mnt) ? " ro" : " rw");
-	show_sb_opts(m, mnt->mnt_sb);
+	err = show_sb_opts(m, mnt->mnt_sb);
 	show_mnt_opts(m, mnt);
-	if (mnt->mnt_sb->s_op->show_options)
+	if (!err && mnt->mnt_sb->s_op->show_options)
 		err = mnt->mnt_sb->s_op->show_options(m, mnt);
 	seq_puts(m, " 0 0\n");
 	return err;

@@ -863,8 +865,8 @@ static int show_mountinfo(struct seq_fil
 	seq_putc(m, ' ');
 	mangle(m, mnt->mnt_devname ? mnt->mnt_devname : "none");
 	seq_puts(m, sb->s_flags & MS_RDONLY ? " ro" : " rw");
-	show_sb_opts(m, sb);
-	if (sb->s_op->show_options)
+	err = show_sb_opts(m, sb);
+	if (!err && sb->s_op->show_options)
 		err = sb->s_op->show_options(m, mnt);
 	seq_putc(m, '\n');
 	return err;

Quoted 5 lines

I'm ignoring seq_* failures. Which kinda scares me since it means i could get half of one option and half of another and the user would not realize it. Maybe I should build a single string for each selinux option and do a single seq_puts() so seq_* failure only means missing options, not possibly corrupted options...

And is it even adequate to return an incomplete set of options with no indication of truncation to userspace? How do we expect userland to use the /proc/mounts output?

Quoted 2 lines

Where's 1/2? I've ported this to the tip of the vfs-2.6 tree, but can't compile it without the other half.

I have a question for everyone though. How are these options used? SELinux mount options can contain commas. When sending such options from userspace they are inside quotes. Should I go ahead and quote selinux options so they can be directly used back into mount commands?

Should I just leave them in there without quotes and let anyone who tries to feel them back into mount figure it out?

I'm ignoring seq_* failures. Which kinda scares me since it means i could get half of one option and half of another and the user would not realize it. Maybe I should build a single string for each selinux option and do a single seq_puts() so seq_* failure only means missing options, not possibly corrupted options...

Quoted 8 lines · Miklos Szeredi

Quoted 2 lines

Where's 1/2? I've ported this to the tip of the vfs-2.6 tree, but can't compile it without the other half.

I have a question for everyone though. How are these options used? SELinux mount options can contain commas. When sending such options from userspace they are inside quotes. Should I go ahead and quote selinux options so they can be directly used back into mount commands?

Yes.

Quoted 2 lines

Should I just leave them in there without quotes and let anyone who tries to feel them back into mount figure it out?

Ideally copying the options out of /proc/mounts, then doing a mount with those options should exactly duplicate the original mount.

Quoted 5 lines

I'm ignoring seq_* failures. Which kinda scares me since it means i could get half of one option and half of another and the user would not realize it. Maybe I should build a single string for each selinux option and do a single seq_puts() so seq_* failure only means missing options, not possibly corrupted options...

Errors from seq_* can be safely ignored, seq_file remembers that there was an error.

Quoted 23 lines · Miklos Szeredi

Quoted 8 lines · Miklos Szeredi

Quoted 2 lines

Where's 1/2? I've ported this to the tip of the vfs-2.6 tree, but can't compile it without the other half.

I have a question for everyone though. How are these options used? SELinux mount options can contain commas. When sending such options from userspace they are inside quotes. Should I go ahead and quote selinux options so they can be directly used back into mount commands?

Yes.

Quoted 2 lines

Should I just leave them in there without quotes and let anyone who tries to feel them back into mount figure it out?

Ideally copying the options out of /proc/mounts, then doing a mount with those options should exactly duplicate the original mount.

Quoted 5 lines

I'm ignoring seq_* failures. Which kinda scares me since it means i could get half of one option and half of another and the user would not realize it. Maybe I should build a single string for each selinux option and do a single seq_puts() so seq_* failure only means missing options, not possibly corrupted options...

Quoted 2 lines

Errors from seq_* can be safely ignored, seq_file remembers that there was an error.

Pardon my ignorance, but can you point to where in the code this is done? Offhand, it seems like seq_putc and seq_puts overflow will be ignored if the caller (in this case, Eric's code - selinux_write_opts) doesn't propagate the error status back up the call chain, and we'll just end up with a truncated list of options.

This patch causes SELinux mount options to show up in /proc/mounts. As with other code in the area seq_put errors are ignored. Other LSM's will not have their mount options displayed until they fill in their own security_sb_show_options() function.

Signed-off-by Eric Paris <[email protected]>

Signed-off-by Miklos Szeredi <[email protected]>

---

This patch is against a merged vfs-2.6:vfs-2.6.25 and selinux:for-akpm repo. It requires the a6307a583a073f85c38399c1e2c21dfe2d6a3da0 changeset in jame's repo to compile. I'll let you and James decide if we should push it through the VFS tree or the SELinux tree....

Only change from the last patch is the addition of " around mount
options which contain a comma example:
server:/export/ /import nfs rw,context="system_u:object_r:httpd_sys_content_t:s0:c1,c3",vers=3,rsize=32768,wsize=32768,hard,proto=tcp,timeo=600,retrans=2,sec=sys,addr=X.X.X.X 0 0

Quoted 10 lines

This patch causes SELinux mount options to show up in /proc/mounts. As with other code in the area seq_put errors are ignored. Other LSM's will not have their mount options displayed until they fill in their own security_sb_show_options() function.

Signed-off-by Eric Paris <[email protected]>

Signed-off-by Miklos Szeredi <[email protected]>

---

Quoted 8 lines

This patch is against a merged vfs-2.6:vfs-2.6.25 and selinux:for-akpm repo. It requires the a6307a583a073f85c38399c1e2c21dfe2d6a3da0 changeset in jame's repo to compile. I'll let you and James decide if we should push it through the VFS tree or the SELinux tree....

Only change from the last patch is the addition of " around mount options which contain a comma example:
server:/export/ /import nfs

0 0

Looks good.

Since the patch is dependent on stuff in the selinux repo, it should go via that tree.

Even better would be if the non-selinux part was split off into a separate patch and gone through -mm, to let the interface changes get extra review.

This patch causes SELinux mount options to show up in /proc/mounts. As with other code in the area seq_put errors are ignored. Other LSM's will not have their mount options displayed until they fill in their own security_sb_show_options() function.

Signed-off-by Eric Paris <[email protected]>

Signed-off-by Miklos Szeredi <[email protected]>

---

This patch is against a merged vfs-2.6:vfs-2.6.25 and selinux:for-akpm repo. It requires the a6307a583a073f85c38399c1e2c21dfe2d6a3da0 changeset in jame's repo to compile. I'll let you and James decide if we should push it through the VFS tree or the SELinux tree....

Quoted 8 lines · Eric Paris

This patch causes SELinux mount options to show up in /proc/mounts. As with other code in the area seq_put errors are ignored. Other LSM's will not have their mount options displayed until they fill in their own security_sb_show_options() function.

Signed-off-by Eric Paris <[email protected]>

Signed-off-by Miklos Szeredi <[email protected]>

Quoted 6 lines

---

This patch is against a merged vfs-2.6:vfs-2.6.25 and selinux:for-akpm repo. It requires the a6307a583a073f85c38399c1e2c21dfe2d6a3da0 changeset in jame's repo to compile. I'll let you and James decide if we should push it through the VFS tree or the SELinux tree....

It doesn't apply to my for-akpm branch.

http://git.kernel.org/?p=linux/kernel/git/viro/vfs-2.6.git;a=commitdiff;h=a0d807802dfe1496a52483cc540b2ab440158f41#patch12

which is in the VFS tree.....

suggestions anyone on the best way to get this merged?

Quoted 7 lines

Quoted 5 lines

This patch is against a merged vfs-2.6:vfs-2.6.25 and selinux:for-akpm repo. It requires the a6307a583a073f85c38399c1e2c21dfe2d6a3da0 changeset in jame's repo to compile. I'll let you and James decide if we should push it through the VFS tree or the SELinux tree....

It doesn't apply to my for-akpm branch.

I said it was against multiple devel trees and I didn't know how it was going to go in.

It needs:

http://git.kernel.org/?p=linux/kernel/git/viro/vfs-2.6.git;a=commitdiff;h=a0d807802dfe1496a52483cc540b2ab440158f41#patch12

which is in the VFS tree.....

suggestions anyone on the best way to get this merged?