Messages in this thread | | | Date | Tue, 5 Jul 2022 16:34:16 +0300 | Subject | Re: [PATCH 1/2] ntfs3: fix NULL deref in ntfs_update_mftmirr | From | Konstantin Komarov <> |
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On 6/9/22 19:42, Konstantin Komarov wrote: > > > 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@syzkaller.appspotmail.com >>> Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> >> >> 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!
I've accepted both patches. I don't want to invent convoluted logic for mftmirr. Thanks again for your work!
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