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authorPavel Skripkin <paskripkin@gmail.com>2022-04-21 23:53:36 +0300
committerKonstantin Komarov <almaz.alexandrovich@paragon-software.com>2022-07-05 16:07:46 +0300
commit321460ca3b55f48b3ba6008248264ab2bd6407d9 (patch)
treeafd50c0dcec9dee0d6a4cc4d7279488583a62038 /fs/ntfs3
parente4d2f4fd5341064d2b3c5158da69421a581e7ec1 (diff)
downloadlinux-321460ca3b55f48b3ba6008248264ab2bd6407d9.tar.xz
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.c7
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;