diff options
author | Al Viro <viro@zeniv.linux.org.uk> | 2018-12-10 17:19:21 -0500 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2018-12-21 11:47:08 -0500 |
commit | a65001e8a4d465693d0191297a6fd864c96b3147 (patch) | |
tree | 7acb5223eea40be8e9f2089e654738f06630a0ac /fs | |
parent | 8d64124a6a93ec68fda6f781e48a7b95d9dd17d9 (diff) | |
download | linux-stable-a65001e8a4d465693d0191297a6fd864c96b3147.tar.gz linux-stable-a65001e8a4d465693d0191297a6fd864c96b3147.tar.bz2 linux-stable-a65001e8a4d465693d0191297a6fd864c96b3147.zip |
btrfs: sanitize security_mnt_opts use
1) keeping a copy in btrfs_fs_info is completely pointless - we never
use it for anything. Getting rid of that allows for simpler calling
conventions for setup_security_options() (caller is responsible for
freeing mnt_opts in all cases).
2) on remount we want to use ->sb_remount(), not ->sb_set_mnt_opts(),
same as we would if not for FS_BINARY_MOUNTDATA. Behaviours *are*
close (in fact, selinux sb_set_mnt_opts() ought to punt to
sb_remount() in "already initialized" case), but let's handle
that uniformly. And the only reason why the original btrfs changes
didn't go for security_sb_remount() in btrfs_remount() case is that
it hadn't been exported. Let's export it for a while - it'll be
going away soon anyway.
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/btrfs/ctree.h | 4 | ||||
-rw-r--r-- | fs/btrfs/super.c | 63 |
2 files changed, 9 insertions, 58 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 80953528572d..f7ec833e6c7a 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1100,9 +1100,6 @@ struct btrfs_fs_info { struct mutex unused_bg_unpin_mutex; struct mutex delete_unused_bgs_mutex; - /* For btrfs to record security options */ - struct security_mnt_opts security_opts; - /* * Chunks that can't be freed yet (under a trim/discard operation) * and will be latter freed. Protected by fs_info->chunk_mutex. @@ -2959,7 +2956,6 @@ static inline void free_fs_info(struct btrfs_fs_info *fs_info) kfree(fs_info->free_space_root); kfree(fs_info->super_copy); kfree(fs_info->super_for_commit); - security_free_mnt_opts(&fs_info->security_opts); kvfree(fs_info); } diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 6fc8e963ad44..3b04e7735b5f 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1458,43 +1458,6 @@ out: return root; } -static int parse_security_options(char *orig_opts, - struct security_mnt_opts *sec_opts) -{ - return security_sb_eat_lsm_opts(orig_opts, sec_opts); -} - -static int setup_security_options(struct btrfs_fs_info *fs_info, - struct super_block *sb, - struct security_mnt_opts *sec_opts) -{ - int ret = 0; - - /* - * Call security_sb_set_mnt_opts() to check whether new sec_opts - * is valid. - */ - ret = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL); - if (ret) - return ret; - -#ifdef CONFIG_SECURITY - if (!fs_info->security_opts.num_mnt_opts) { - /* first time security setup, copy sec_opts to fs_info */ - memcpy(&fs_info->security_opts, sec_opts, sizeof(*sec_opts)); - } else { - /* - * Since SELinux (the only one supporting security_mnt_opts) - * does NOT support changing context during remount/mount of - * the same sb, this must be the same or part of the same - * security options, just free it. - */ - security_free_mnt_opts(sec_opts); - } -#endif - return ret; -} - /* * Find a superblock for the given device / mount point. * @@ -1518,7 +1481,7 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type, security_init_mnt_opts(&new_sec_opts); if (data) { - error = parse_security_options(data, &new_sec_opts); + error = security_sb_eat_lsm_opts(data, &new_sec_opts); if (error) return ERR_PTR(error); } @@ -1537,7 +1500,6 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type, fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL); fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL); - security_init_mnt_opts(&fs_info->security_opts); if (!fs_info->super_copy || !fs_info->super_for_commit) { error = -ENOMEM; goto error_fs_info; @@ -1588,16 +1550,12 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type, btrfs_sb(s)->bdev_holder = fs_type; error = btrfs_fill_super(s, fs_devices, data); } + if (!error) + error = security_sb_set_mnt_opts(s, &new_sec_opts, 0, NULL); + security_free_mnt_opts(&new_sec_opts); if (error) { deactivate_locked_super(s); - goto error_sec_opts; - } - - fs_info = btrfs_sb(s); - error = setup_security_options(fs_info, s, &new_sec_opts); - if (error) { - deactivate_locked_super(s); - goto error_sec_opts; + return ERR_PTR(error); } return dget(s->s_root); @@ -1769,15 +1727,12 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data) struct security_mnt_opts new_sec_opts; security_init_mnt_opts(&new_sec_opts); - ret = parse_security_options(data, &new_sec_opts); + ret = security_sb_eat_lsm_opts(data, &new_sec_opts); + if (!ret) + ret = security_sb_remount(sb, &new_sec_opts); + security_free_mnt_opts(&new_sec_opts); if (ret) goto restore; - ret = setup_security_options(fs_info, sb, - &new_sec_opts); - if (ret) { - security_free_mnt_opts(&new_sec_opts); - goto restore; - } } ret = btrfs_parse_options(fs_info, data, *flags); |