On 6/4/22 14:42, Pavel Skripkin wrote:
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@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Pavel Skripkin <paskripkin@xxxxxxxxx>gentle ping With regards, Pavel Skripkin
1st patch is correct. 2nd patch is a good catch, but I'm not sure if simply ignoring is good. If mftmirr is broken / missing, then theoretically we can continue working. But still it's a major fs error. I'm thinking about exiting mount with error, and if "force" is present, then continue with mount. I'll reply again when I'll be sure what is correct behavior. Thank you for your work!
