diff options
| author | Pavel Skripkin <paskripkin@gmail.com> | 2022-04-21 23:53:36 +0300 |
|---|---|---|
| committer | Konstantin Komarov <almaz.alexandrovich@paragon-software.com> | 2022-07-05 16:07:46 +0300 |
| commit | 321460ca3b55f48b3ba6008248264ab2bd6407d9 (patch) | |
| tree | afd50c0dcec9dee0d6a4cc4d7279488583a62038 /fs/ntfs3 | |
| parent | e4d2f4fd5341064d2b3c5158da69421a581e7ec1 (diff) | |
fs/ntfs3: Fix NULL deref in ntfs_update_mftmirr
If ntfs_fill_super() wasn't called then sbi->sb will be equal to NULL.
Code should check this ptr before dereferencing. Syzbot hit this issue
via passing wrong mount param as can be seen from log below
Fail log:
ntfs3: Unknown parameter 'iochvrset'
general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 1 PID: 3589 Comm: syz-executor210 Not tainted 5.18.0-rc3-syzkaller-00016-gb253435746d9 #0
...
Call Trace:
<TASK>
put_ntfs+0x1ed/0x2a0 fs/ntfs3/super.c:463
ntfs_fs_free+0x6a/0xe0 fs/ntfs3/super.c:1363
put_fs_context+0x119/0x7a0 fs/fs_context.c:469
do_new_mount+0x2b4/0xad0 fs/namespace.c:3044
do_mount fs/namespace.c:3383 [inline]
__do_sys_mount fs/namespace.c:3591 [inline]
Fixes: 82cae269cfa9 ("fs/ntfs3: Add initialization of super block")
Reported-and-tested-by: syzbot+c95173762127ad76a824@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Diffstat (limited to 'fs/ntfs3')
| -rw-r--r-- | fs/ntfs3/fsntfs.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/fs/ntfs3/fsntfs.c b/fs/ntfs3/fsntfs.c index 3de5700a9b83..891125ca6848 100644 --- a/fs/ntfs3/fsntfs.c +++ b/fs/ntfs3/fsntfs.c @@ -831,10 +831,15 @@ int ntfs_update_mftmirr(struct ntfs_sb_info *sbi, int wait) { int err; struct super_block *sb = sbi->sb; - u32 blocksize = sb->s_blocksize; + u32 blocksize; sector_t block1, block2; u32 bytes; + if (!sb) + return -EINVAL; + + blocksize = sb->s_blocksize; + if (!(sbi->flags & NTFS_FLAGS_MFTMIRR)) return 0; |