Skip to content

Commit

Permalink
LSM/SELinux: show LSM mount options in /proc/mounts
Browse files Browse the repository at this point in the history 
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 <eparis@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: James Morris <jmorris@namei.org>
  • Loading branch information
Eric Paris authored and James Morris committed Jul 14, 2008
1 parent 811f379 commit 2069f45
Show file tree
Hide file tree
Showing 5 changed files with 85 additions and 4 deletions.
14 changes: 11 additions & 3 deletions fs/namespace.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -750,7 +750,7 @@ 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" },
Expand All @@ -764,6 +764,8 @@ static void show_sb_opts(struct seq_file *m, struct super_block *sb)
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)
Expand Down Expand Up @@ -806,11 +808,14 @@ static int show_vfsmnt(struct seq_file *m, void *v)
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);
if (err)
goto out;
show_mnt_opts(m, mnt);
if (mnt->mnt_sb->s_op->show_options)
err = mnt->mnt_sb->s_op->show_options(m, mnt);
seq_puts(m, " 0 0\n");
out:
return err;
}

Expand Down Expand Up @@ -865,10 +870,13 @@ static int show_mountinfo(struct seq_file *m, void *v)
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);
err = show_sb_opts(m, sb);
if (err)
goto out;
if (sb->s_op->show_options)
err = sb->s_op->show_options(m, mnt);
seq_putc(m, '\n');
out:
return err;
}

Expand Down
9 changes: 9 additions & 0 deletions include/linux/security.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -80,6 +80,7 @@ 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);
Expand Down Expand Up @@ -1331,6 +1332,7 @@ 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);
Expand Down Expand Up @@ -1610,6 +1612,7 @@ int security_sb_alloc(struct super_block *sb);
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);
Expand Down Expand Up @@ -1887,6 +1890,12 @@ static inline int security_sb_kern_mount(struct super_block *sb, void *data)
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;
Expand Down
6 changes: 6 additions & 0 deletions security/dummy.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -194,6 +194,11 @@ static int dummy_sb_kern_mount (struct super_block *sb, void *data)
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;
Expand Down Expand Up @@ -1088,6 +1093,7 @@ void security_fixup_ops (struct security_operations *ops)
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);
Expand Down
5 changes: 5 additions & 0 deletions security/security.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -292,6 +292,11 @@ int security_sb_kern_mount(struct super_block *sb, void *data)
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);
Expand Down
55 changes: 54 additions & 1 deletion security/selinux/hooks.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,8 @@
* James Morris <jmorris@redhat.com>
*
* Copyright (C) 2001,2002 Networks Associates Technology, Inc.
* Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
* Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
* Eric Paris <eparis@redhat.com>
* Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
* <dgoeddel@trustedcs.com>
* Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
Expand Down Expand Up @@ -970,6 +971,57 @@ static int superblock_doinit(struct super_block *sb, void *data)
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++) {
char *has_comma = strchr(opts->mnt_opts[i], ',');

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();
};
/* we need a comma before each option */
seq_putc(m, ',');
seq_puts(m, prefix);
if (has_comma)
seq_putc(m, '\"');
seq_puts(m, opts->mnt_opts[i]);
if (has_comma)
seq_putc(m, '\"');
}
}

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) {
Expand Down Expand Up @@ -5365,6 +5417,7 @@ static struct security_operations selinux_ops = {
.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,
Expand Down

0 comments on commit 2069f45

Please sign in to comment.