LSM/SELinux: show LSM mount options in /proc/mounts
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>
diff --git a/fs/namespace.c b/fs/namespace.c
index 4fc302c..4f6f763 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -750,7 +750,7 @@
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" },
@@ -764,6 +764,8 @@
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)
@@ -806,11 +808,14 @@
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;
}
@@ -865,10 +870,13 @@
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;
}
diff --git a/include/linux/security.h b/include/linux/security.h
index 62bd80c..c8ad8ec 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -80,6 +80,7 @@
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);
@@ -1331,6 +1332,7 @@
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);
@@ -1610,6 +1612,7 @@
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);
@@ -1887,6 +1890,12 @@
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;
diff --git a/security/dummy.c b/security/dummy.c
index 1db712d..c155f08 100644
--- a/security/dummy.c
+++ b/security/dummy.c
@@ -194,6 +194,11 @@
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;
@@ -1088,6 +1093,7 @@
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);
diff --git a/security/security.c b/security/security.c
index 2c0a587..de74fdc 100644
--- a/security/security.c
+++ b/security/security.c
@@ -292,6 +292,11 @@
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);
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 85f74f6..33dee83 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -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.
@@ -970,6 +971,57 @@
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) {
@@ -5365,6 +5417,7 @@
.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,