On 4/21/22 23:53, Pavel Skripkin wrote:
> 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>

gentle ping




With regards,
Pavel Skripkin