INFO: task can't die in corrupted

INFO: task can't die in corrupted

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    a804ab08 Add linux-next specific files for 20201006
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
compiler:       gcc (GCC) 10.1.0-syz 20200507
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000

The issue was bisected to:

commit eede846af512572b1f30b34f9889d7df64c017d4
Author: Jaegeuk Kim <jaegeuk@kernel.org>
Date:   Fri Oct 2 21:17:35 2020 +0000

    f2fs: f2fs_get_meta_page_nofail should not be failed

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10a8aafb900000
console output: https://syzkaller.appspot.com/x/log.txt?x=14a8aafb900000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ee250ac8137be41d7b13@syzkaller.appspotmail.com
Fixes: eede846af512 ("f2fs: f2fs_get_meta_page_nofail should not be failed")

INFO: task syz-executor178:6870 can't die for more than 143 seconds.
task:syz-executor178 state:R
 stack:26960 pid: 6870 ppid:  6869 flags:0x00004006
Call Trace:

Showing all locks held in the system:
1 lock held by khungtaskd/1179:
 #0: ffffffff8a554da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6242
1 lock held by systemd-journal/3920:
1 lock held by in:imklog/6769:
 #0: ffff88809eebc130 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930
1 lock held by syz-executor178/6870:
 #0: ffff8880925120e0 (&type->s_umount_key#47/1){+.+.}-{3:3}, at: alloc_super+0x201/0xaf0 fs/super.c:229

=============================================

Kernel panic - not syncing: hung_task: blocked tasks
CPU: 0 PID: 1179 Comm: khungtaskd Not tainted 5.9.0-rc8-next-20201006-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x198/0x1fb lib/dump_stack.c:118
 panic+0x382/0x7fb kernel/panic.c:231
 check_hung_uninterruptible_tasks kernel/hung_task.c:257 [inline]
 watchdog.cold+0x23e/0x248 kernel/hung_task.c:339
 kthread+0x3af/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches

[f2fs-dev] INFO: task can't die in corrupted

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    a804ab08 Add linux-next specific files for 20201006
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
compiler:       gcc (GCC) 10.1.0-syz 20200507
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000

The issue was bisected to:

commit eede846af512572b1f30b34f9889d7df64c017d4
Author: Jaegeuk Kim <jaegeuk@kernel.org>
Date:   Fri Oct 2 21:17:35 2020 +0000

    f2fs: f2fs_get_meta_page_nofail should not be failed

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=10a8aafb900000
console output: https://syzkaller.appspot.com/x/log.txt?x=14a8aafb900000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ee250ac8137be41d7b13@syzkaller.appspotmail.com
Fixes: eede846af512 ("f2fs: f2fs_get_meta_page_nofail should not be failed")

INFO: task syz-executor178:6870 can't die for more than 143 seconds.
task:syz-executor178 state:R
 stack:26960 pid: 6870 ppid:  6869 flags:0x00004006
Call Trace:

Showing all locks held in the system:
1 lock held by khungtaskd/1179:
 #0: ffffffff8a554da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6242
1 lock held by systemd-journal/3920:
1 lock held by in:imklog/6769:
 #0: ffff88809eebc130 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930
1 lock held by syz-executor178/6870:
 #0: ffff8880925120e0 (&type->s_umount_key#47/1){+.+.}-{3:3}, at: alloc_super+0x201/0xaf0 fs/super.c:229

=============================================

Kernel panic - not syncing: hung_task: blocked tasks
CPU: 0 PID: 1179 Comm: khungtaskd Not tainted 5.9.0-rc8-next-20201006-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x198/0x1fb lib/dump_stack.c:118
 panic+0x382/0x7fb kernel/panic.c:231
 check_hung_uninterruptible_tasks kernel/hung_task.c:257 [inline]
 watchdog.cold+0x23e/0x248 kernel/hung_task.c:339
 kthread+0x3af/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
Kernel Offset: disabled
Rebooting in 86400 seconds..


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches


_______________________________________________
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https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

[f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[Eric Biggers]

[moved linux-fsdevel to Bcc]

On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    a804ab08 Add linux-next specific files for 20201006
> git tree:       linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
> dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
> compiler:       gcc (GCC) 10.1.0-syz 20200507
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
> 
> The issue was bisected to:
> 
> commit eede846af512572b1f30b34f9889d7df64c017d4
> Author: Jaegeuk Kim <jaegeuk@kernel.org>
> Date:   Fri Oct 2 21:17:35 2020 +0000
> 
>     f2fs: f2fs_get_meta_page_nofail should not be failed
> 

Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
if the requested page is beyond the end of the device.

- Eric

[f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[Eric Biggers]

[moved linux-fsdevel to Bcc]

On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    a804ab08 Add linux-next specific files for 20201006
> git tree:       linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
> dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
> compiler:       gcc (GCC) 10.1.0-syz 20200507
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
> 
> The issue was bisected to:
> 
> commit eede846af512572b1f30b34f9889d7df64c017d4
> Author: Jaegeuk Kim <jaegeuk@kernel.org>
> Date:   Fri Oct 2 21:17:35 2020 +0000
> 
>     f2fs: f2fs_get_meta_page_nofail should not be failed
> 

Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
if the requested page is beyond the end of the device.

- Eric


_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Re: [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[jaegeuk]

On 10/07, Eric Biggers wrote:
> [moved linux-fsdevel to Bcc]
> 
> On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
> > Hello,
> > 
> > syzbot found the following issue on:
> > 
> > HEAD commit:    a804ab08 Add linux-next specific files for 20201006
> > git tree:       linux-next
> > console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
> > dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
> > compiler:       gcc (GCC) 10.1.0-syz 20200507
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
> > 
> > The issue was bisected to:
> > 
> > commit eede846af512572b1f30b34f9889d7df64c017d4
> > Author: Jaegeuk Kim <jaegeuk@kernel.org>
> > Date:   Fri Oct 2 21:17:35 2020 +0000
> > 
> >     f2fs: f2fs_get_meta_page_nofail should not be failed
> > 
> 
> Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
> if the requested page is beyond the end of the device.

Yes, that will go infinite loop. Otherwise, it will trigger a panic during
the device reboot. Let me think how to avoid that before trying to get the
wrong lba access.

> 
> - Eric

Re: [f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[jaegeuk]

On 10/07, Eric Biggers wrote:
> [moved linux-fsdevel to Bcc]
> 
> On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
> > Hello,
> > 
> > syzbot found the following issue on:
> > 
> > HEAD commit:    a804ab08 Add linux-next specific files for 20201006
> > git tree:       linux-next
> > console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
> > dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
> > compiler:       gcc (GCC) 10.1.0-syz 20200507
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
> > 
> > The issue was bisected to:
> > 
> > commit eede846af512572b1f30b34f9889d7df64c017d4
> > Author: Jaegeuk Kim <jaegeuk@kernel.org>
> > Date:   Fri Oct 2 21:17:35 2020 +0000
> > 
> >     f2fs: f2fs_get_meta_page_nofail should not be failed
> > 
> 
> Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
> if the requested page is beyond the end of the device.

Yes, that will go infinite loop. Otherwise, it will trigger a panic during
the device reboot. Let me think how to avoid that before trying to get the
wrong lba access.

> 
> - Eric


_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Re: [f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[Chao Yu]

On 2020/10/8 5:53, jaegeuk@kernel.org wrote:
> On 10/07, Eric Biggers wrote:
>> [moved linux-fsdevel to Bcc]
>>
>> On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
>>> Hello,
>>>
>>> syzbot found the following issue on:
>>>
>>> HEAD commit:    a804ab08 Add linux-next specific files for 20201006
>>> git tree:       linux-next
>>> console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
>>> kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
>>> dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
>>> compiler:       gcc (GCC) 10.1.0-syz 20200507
>>> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
>>> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
>>>
>>> The issue was bisected to:
>>>
>>> commit eede846af512572b1f30b34f9889d7df64c017d4
>>> Author: Jaegeuk Kim <jaegeuk@kernel.org>
>>> Date:   Fri Oct 2 21:17:35 2020 +0000
>>>
>>>      f2fs: f2fs_get_meta_page_nofail should not be failed
>>>
>>
>> Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
>> if the requested page is beyond the end of the device.
> 
> Yes, that will go infinite loop. Otherwise, it will trigger a panic during
> the device reboot. Let me think how to avoid that before trying to get the
> wrong lba access.

Delivering f2fs_get_sum_page()'s return value needs a lot of codes change, I think
we can just zeroing sum_page in error case, as we have already shutdown f2fs via
calling f2fs_stop_checkpoint(), then f2fs_cp_error() will stop all updates to
filesystem data including summary pages.

Thoughts?

Thanks,

> 
>>
>> - Eric
> 
> 
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> .
> 

Re: [f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[Chao Yu]

On 2020/10/8 5:53, jaegeuk@kernel.org wrote:
> On 10/07, Eric Biggers wrote:
>> [moved linux-fsdevel to Bcc]
>>
>> On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
>>> Hello,
>>>
>>> syzbot found the following issue on:
>>>
>>> HEAD commit:    a804ab08 Add linux-next specific files for 20201006
>>> git tree:       linux-next
>>> console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
>>> kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
>>> dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
>>> compiler:       gcc (GCC) 10.1.0-syz 20200507
>>> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
>>> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
>>>
>>> The issue was bisected to:
>>>
>>> commit eede846af512572b1f30b34f9889d7df64c017d4
>>> Author: Jaegeuk Kim <jaegeuk@kernel.org>
>>> Date:   Fri Oct 2 21:17:35 2020 +0000
>>>
>>>      f2fs: f2fs_get_meta_page_nofail should not be failed
>>>
>>
>> Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
>> if the requested page is beyond the end of the device.
> 
> Yes, that will go infinite loop. Otherwise, it will trigger a panic during
> the device reboot. Let me think how to avoid that before trying to get the
> wrong lba access.

Delivering f2fs_get_sum_page()'s return value needs a lot of codes change, I think
we can just zeroing sum_page in error case, as we have already shutdown f2fs via
calling f2fs_stop_checkpoint(), then f2fs_cp_error() will stop all updates to
filesystem data including summary pages.

Thoughts?

Thanks,

> 
>>
>> - Eric
> 
> 
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> .
> 


_______________________________________________
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Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Re: [f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[jaegeuk]

On 10/09, Chao Yu wrote:
> On 2020/10/8 5:53, jaegeuk@kernel.org wrote:
> > On 10/07, Eric Biggers wrote:
> > > [moved linux-fsdevel to Bcc]
> > > 
> > > On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
> > > > Hello,
> > > > 
> > > > syzbot found the following issue on:
> > > > 
> > > > HEAD commit:    a804ab08 Add linux-next specific files for 20201006
> > > > git tree:       linux-next
> > > > console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
> > > > kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
> > > > dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
> > > > compiler:       gcc (GCC) 10.1.0-syz 20200507
> > > > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
> > > > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
> > > > 
> > > > The issue was bisected to:
> > > > 
> > > > commit eede846af512572b1f30b34f9889d7df64c017d4
> > > > Author: Jaegeuk Kim <jaegeuk@kernel.org>
> > > > Date:   Fri Oct 2 21:17:35 2020 +0000
> > > > 
> > > >      f2fs: f2fs_get_meta_page_nofail should not be failed
> > > > 
> > > 
> > > Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
> > > if the requested page is beyond the end of the device.
> > 
> > Yes, that will go infinite loop. Otherwise, it will trigger a panic during
> > the device reboot. Let me think how to avoid that before trying to get the
> > wrong lba access.
> 
> Delivering f2fs_get_sum_page()'s return value needs a lot of codes change, I think
> we can just zeroing sum_page in error case, as we have already shutdown f2fs via
> calling f2fs_stop_checkpoint(), then f2fs_cp_error() will stop all updates to
> filesystem data including summary pages.

That sounds like one solution tho, I'm afraid of getting another panic by
wrong zero'ed summary page.

> 
> Thoughts?
> 
> Thanks,
> 
> > 
> > > 
> > > - Eric
> > 
> > 
> > _______________________________________________
> > Linux-f2fs-devel mailing list
> > Linux-f2fs-devel@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> > .
> > 

Re: [f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[jaegeuk]

On 10/09, Chao Yu wrote:
> On 2020/10/8 5:53, jaegeuk@kernel.org wrote:
> > On 10/07, Eric Biggers wrote:
> > > [moved linux-fsdevel to Bcc]
> > > 
> > > On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
> > > > Hello,
> > > > 
> > > > syzbot found the following issue on:
> > > > 
> > > > HEAD commit:    a804ab08 Add linux-next specific files for 20201006
> > > > git tree:       linux-next
> > > > console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
> > > > kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
> > > > dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
> > > > compiler:       gcc (GCC) 10.1.0-syz 20200507
> > > > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
> > > > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
> > > > 
> > > > The issue was bisected to:
> > > > 
> > > > commit eede846af512572b1f30b34f9889d7df64c017d4
> > > > Author: Jaegeuk Kim <jaegeuk@kernel.org>
> > > > Date:   Fri Oct 2 21:17:35 2020 +0000
> > > > 
> > > >      f2fs: f2fs_get_meta_page_nofail should not be failed
> > > > 
> > > 
> > > Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
> > > if the requested page is beyond the end of the device.
> > 
> > Yes, that will go infinite loop. Otherwise, it will trigger a panic during
> > the device reboot. Let me think how to avoid that before trying to get the
> > wrong lba access.
> 
> Delivering f2fs_get_sum_page()'s return value needs a lot of codes change, I think
> we can just zeroing sum_page in error case, as we have already shutdown f2fs via
> calling f2fs_stop_checkpoint(), then f2fs_cp_error() will stop all updates to
> filesystem data including summary pages.

That sounds like one solution tho, I'm afraid of getting another panic by
wrong zero'ed summary page.

> 
> Thoughts?
> 
> Thanks,
> 
> > 
> > > 
> > > - Eric
> > 
> > 
> > _______________________________________________
> > Linux-f2fs-devel mailing list
> > Linux-f2fs-devel@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> > .
> > 


_______________________________________________
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https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Re: [f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[Chao Yu]

On 2020/10/9 9:50, jaegeuk@kernel.org wrote:
> On 10/09, Chao Yu wrote:
>> On 2020/10/8 5:53, jaegeuk@kernel.org wrote:
>>> On 10/07, Eric Biggers wrote:
>>>> [moved linux-fsdevel to Bcc]
>>>>
>>>> On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
>>>>> Hello,
>>>>>
>>>>> syzbot found the following issue on:
>>>>>
>>>>> HEAD commit:    a804ab08 Add linux-next specific files for 20201006
>>>>> git tree:       linux-next
>>>>> console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
>>>>> kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
>>>>> dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
>>>>> compiler:       gcc (GCC) 10.1.0-syz 20200507
>>>>> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
>>>>> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
>>>>>
>>>>> The issue was bisected to:
>>>>>
>>>>> commit eede846af512572b1f30b34f9889d7df64c017d4
>>>>> Author: Jaegeuk Kim <jaegeuk@kernel.org>
>>>>> Date:   Fri Oct 2 21:17:35 2020 +0000
>>>>>
>>>>>       f2fs: f2fs_get_meta_page_nofail should not be failed
>>>>>
>>>>
>>>> Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
>>>> if the requested page is beyond the end of the device.
>>>
>>> Yes, that will go infinite loop. Otherwise, it will trigger a panic during
>>> the device reboot. Let me think how to avoid that before trying to get the
>>> wrong lba access.
>>
>> Delivering f2fs_get_sum_page()'s return value needs a lot of codes change, I think
>> we can just zeroing sum_page in error case, as we have already shutdown f2fs via
>> calling f2fs_stop_checkpoint(), then f2fs_cp_error() will stop all updates to
>> filesystem data including summary pages.
> 
> That sounds like one solution tho, I'm afraid of getting another panic by
> wrong zero'ed summary page.

What case do you mean? maybe I missed some corner cases?

Thanks,

> 
>>
>> Thoughts?
>>
>> Thanks,
>>
>>>
>>>>
>>>> - Eric
>>>
>>>
>>> _______________________________________________
>>> Linux-f2fs-devel mailing list
>>> Linux-f2fs-devel@lists.sourceforge.net
>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
>>> .
>>>
> .
> 

Re: [f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[Chao Yu]

On 2020/10/9 9:50, jaegeuk@kernel.org wrote:
> On 10/09, Chao Yu wrote:
>> On 2020/10/8 5:53, jaegeuk@kernel.org wrote:
>>> On 10/07, Eric Biggers wrote:
>>>> [moved linux-fsdevel to Bcc]
>>>>
>>>> On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
>>>>> Hello,
>>>>>
>>>>> syzbot found the following issue on:
>>>>>
>>>>> HEAD commit:    a804ab08 Add linux-next specific files for 20201006
>>>>> git tree:       linux-next
>>>>> console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
>>>>> kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
>>>>> dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
>>>>> compiler:       gcc (GCC) 10.1.0-syz 20200507
>>>>> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
>>>>> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
>>>>>
>>>>> The issue was bisected to:
>>>>>
>>>>> commit eede846af512572b1f30b34f9889d7df64c017d4
>>>>> Author: Jaegeuk Kim <jaegeuk@kernel.org>
>>>>> Date:   Fri Oct 2 21:17:35 2020 +0000
>>>>>
>>>>>       f2fs: f2fs_get_meta_page_nofail should not be failed
>>>>>
>>>>
>>>> Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
>>>> if the requested page is beyond the end of the device.
>>>
>>> Yes, that will go infinite loop. Otherwise, it will trigger a panic during
>>> the device reboot. Let me think how to avoid that before trying to get the
>>> wrong lba access.
>>
>> Delivering f2fs_get_sum_page()'s return value needs a lot of codes change, I think
>> we can just zeroing sum_page in error case, as we have already shutdown f2fs via
>> calling f2fs_stop_checkpoint(), then f2fs_cp_error() will stop all updates to
>> filesystem data including summary pages.
> 
> That sounds like one solution tho, I'm afraid of getting another panic by
> wrong zero'ed summary page.

What case do you mean? maybe I missed some corner cases?

Thanks,

> 
>>
>> Thoughts?
>>
>> Thanks,
>>
>>>
>>>>
>>>> - Eric
>>>
>>>
>>> _______________________________________________
>>> Linux-f2fs-devel mailing list
>>> Linux-f2fs-devel@lists.sourceforge.net
>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
>>> .
>>>
> .
> 


_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Re: [f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[jaegeuk]

On 10/09, Chao Yu wrote:
> On 2020/10/9 9:50, jaegeuk@kernel.org wrote:
> > On 10/09, Chao Yu wrote:
> > > On 2020/10/8 5:53, jaegeuk@kernel.org wrote:
> > > > On 10/07, Eric Biggers wrote:
> > > > > [moved linux-fsdevel to Bcc]
> > > > > 
> > > > > On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
> > > > > > Hello,
> > > > > > 
> > > > > > syzbot found the following issue on:
> > > > > > 
> > > > > > HEAD commit:    a804ab08 Add linux-next specific files for 20201006
> > > > > > git tree:       linux-next
> > > > > > console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
> > > > > > kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
> > > > > > dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
> > > > > > compiler:       gcc (GCC) 10.1.0-syz 20200507
> > > > > > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
> > > > > > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
> > > > > > 
> > > > > > The issue was bisected to:
> > > > > > 
> > > > > > commit eede846af512572b1f30b34f9889d7df64c017d4
> > > > > > Author: Jaegeuk Kim <jaegeuk@kernel.org>
> > > > > > Date:   Fri Oct 2 21:17:35 2020 +0000
> > > > > > 
> > > > > >       f2fs: f2fs_get_meta_page_nofail should not be failed
> > > > > > 
> > > > > 
> > > > > Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
> > > > > if the requested page is beyond the end of the device.
> > > > 
> > > > Yes, that will go infinite loop. Otherwise, it will trigger a panic during
> > > > the device reboot. Let me think how to avoid that before trying to get the
> > > > wrong lba access.
> > > 
> > > Delivering f2fs_get_sum_page()'s return value needs a lot of codes change, I think
> > > we can just zeroing sum_page in error case, as we have already shutdown f2fs via
> > > calling f2fs_stop_checkpoint(), then f2fs_cp_error() will stop all updates to
> > > filesystem data including summary pages.
> > 
> > That sounds like one solution tho, I'm afraid of getting another panic by
> > wrong zero'ed summary page.
> 
> What case do you mean? maybe I missed some corner cases?

I sent v2 to fix syzbot issue, which fixes wrong use of
f2fs_get_meta_page_nofail.

> 
> Thanks,
> 
> > 
> > > 
> > > Thoughts?
> > > 
> > > Thanks,
> > > 
> > > > 
> > > > > 
> > > > > - Eric
> > > > 
> > > > 
> > > > _______________________________________________
> > > > Linux-f2fs-devel mailing list
> > > > Linux-f2fs-devel@lists.sourceforge.net
> > > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> > > > .
> > > > 
> > .
> > 

Re: [f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[jaegeuk]

On 10/09, Chao Yu wrote:
> On 2020/10/9 9:50, jaegeuk@kernel.org wrote:
> > On 10/09, Chao Yu wrote:
> > > On 2020/10/8 5:53, jaegeuk@kernel.org wrote:
> > > > On 10/07, Eric Biggers wrote:
> > > > > [moved linux-fsdevel to Bcc]
> > > > > 
> > > > > On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
> > > > > > Hello,
> > > > > > 
> > > > > > syzbot found the following issue on:
> > > > > > 
> > > > > > HEAD commit:    a804ab08 Add linux-next specific files for 20201006
> > > > > > git tree:       linux-next
> > > > > > console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
> > > > > > kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
> > > > > > dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
> > > > > > compiler:       gcc (GCC) 10.1.0-syz 20200507
> > > > > > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
> > > > > > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
> > > > > > 
> > > > > > The issue was bisected to:
> > > > > > 
> > > > > > commit eede846af512572b1f30b34f9889d7df64c017d4
> > > > > > Author: Jaegeuk Kim <jaegeuk@kernel.org>
> > > > > > Date:   Fri Oct 2 21:17:35 2020 +0000
> > > > > > 
> > > > > >       f2fs: f2fs_get_meta_page_nofail should not be failed
> > > > > > 
> > > > > 
> > > > > Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
> > > > > if the requested page is beyond the end of the device.
> > > > 
> > > > Yes, that will go infinite loop. Otherwise, it will trigger a panic during
> > > > the device reboot. Let me think how to avoid that before trying to get the
> > > > wrong lba access.
> > > 
> > > Delivering f2fs_get_sum_page()'s return value needs a lot of codes change, I think
> > > we can just zeroing sum_page in error case, as we have already shutdown f2fs via
> > > calling f2fs_stop_checkpoint(), then f2fs_cp_error() will stop all updates to
> > > filesystem data including summary pages.
> > 
> > That sounds like one solution tho, I'm afraid of getting another panic by
> > wrong zero'ed summary page.
> 
> What case do you mean? maybe I missed some corner cases?

I sent v2 to fix syzbot issue, which fixes wrong use of
f2fs_get_meta_page_nofail.

> 
> Thanks,
> 
> > 
> > > 
> > > Thoughts?
> > > 
> > > Thanks,
> > > 
> > > > 
> > > > > 
> > > > > - Eric
> > > > 
> > > > 
> > > > _______________________________________________
> > > > Linux-f2fs-devel mailing list
> > > > Linux-f2fs-devel@lists.sourceforge.net
> > > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> > > > .
> > > > 
> > .
> > 


_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Re: [f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[Chao Yu]

On 2020/10/9 12:32, jaegeuk@kernel.org wrote:
> On 10/09, Chao Yu wrote:
>> On 2020/10/9 9:50, jaegeuk@kernel.org wrote:
>>> On 10/09, Chao Yu wrote:
>>>> On 2020/10/8 5:53, jaegeuk@kernel.org wrote:
>>>>> On 10/07, Eric Biggers wrote:
>>>>>> [moved linux-fsdevel to Bcc]
>>>>>>
>>>>>> On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
>>>>>>> Hello,
>>>>>>>
>>>>>>> syzbot found the following issue on:
>>>>>>>
>>>>>>> HEAD commit:    a804ab08 Add linux-next specific files for 20201006
>>>>>>> git tree:       linux-next
>>>>>>> console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
>>>>>>> kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
>>>>>>> dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
>>>>>>> compiler:       gcc (GCC) 10.1.0-syz 20200507
>>>>>>> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
>>>>>>> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
>>>>>>>
>>>>>>> The issue was bisected to:
>>>>>>>
>>>>>>> commit eede846af512572b1f30b34f9889d7df64c017d4
>>>>>>> Author: Jaegeuk Kim <jaegeuk@kernel.org>
>>>>>>> Date:   Fri Oct 2 21:17:35 2020 +0000
>>>>>>>
>>>>>>>        f2fs: f2fs_get_meta_page_nofail should not be failed
>>>>>>>
>>>>>>
>>>>>> Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
>>>>>> if the requested page is beyond the end of the device.
>>>>>
>>>>> Yes, that will go infinite loop. Otherwise, it will trigger a panic during
>>>>> the device reboot. Let me think how to avoid that before trying to get the
>>>>> wrong lba access.
>>>>
>>>> Delivering f2fs_get_sum_page()'s return value needs a lot of codes change, I think
>>>> we can just zeroing sum_page in error case, as we have already shutdown f2fs via
>>>> calling f2fs_stop_checkpoint(), then f2fs_cp_error() will stop all updates to
>>>> filesystem data including summary pages.
>>>
>>> That sounds like one solution tho, I'm afraid of getting another panic by
>>> wrong zero'ed summary page.
>>
>> What case do you mean? maybe I missed some corner cases?
> 
> I sent v2 to fix syzbot issue, which fixes wrong use of
> f2fs_get_meta_page_nofail.

I agreed to fix that case, however we may encounter deadloop in other
places where we call f2fs_get_meta_page_nofail()? like the case that
filesystem will always see EIO after we shutdown device via dmflakey?

Thanks,

> 
>>
>> Thanks,
>>
>>>
>>>>
>>>> Thoughts?
>>>>
>>>> Thanks,
>>>>
>>>>>
>>>>>>
>>>>>> - Eric
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Linux-f2fs-devel mailing list
>>>>> Linux-f2fs-devel@lists.sourceforge.net
>>>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
>>>>> .
>>>>>
>>> .
>>>
> .
> 

Re: [f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[Chao Yu]

On 2020/10/9 12:32, jaegeuk@kernel.org wrote:
> On 10/09, Chao Yu wrote:
>> On 2020/10/9 9:50, jaegeuk@kernel.org wrote:
>>> On 10/09, Chao Yu wrote:
>>>> On 2020/10/8 5:53, jaegeuk@kernel.org wrote:
>>>>> On 10/07, Eric Biggers wrote:
>>>>>> [moved linux-fsdevel to Bcc]
>>>>>>
>>>>>> On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
>>>>>>> Hello,
>>>>>>>
>>>>>>> syzbot found the following issue on:
>>>>>>>
>>>>>>> HEAD commit:    a804ab08 Add linux-next specific files for 20201006
>>>>>>> git tree:       linux-next
>>>>>>> console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
>>>>>>> kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
>>>>>>> dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
>>>>>>> compiler:       gcc (GCC) 10.1.0-syz 20200507
>>>>>>> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
>>>>>>> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
>>>>>>>
>>>>>>> The issue was bisected to:
>>>>>>>
>>>>>>> commit eede846af512572b1f30b34f9889d7df64c017d4
>>>>>>> Author: Jaegeuk Kim <jaegeuk@kernel.org>
>>>>>>> Date:   Fri Oct 2 21:17:35 2020 +0000
>>>>>>>
>>>>>>>        f2fs: f2fs_get_meta_page_nofail should not be failed
>>>>>>>
>>>>>>
>>>>>> Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
>>>>>> if the requested page is beyond the end of the device.
>>>>>
>>>>> Yes, that will go infinite loop. Otherwise, it will trigger a panic during
>>>>> the device reboot. Let me think how to avoid that before trying to get the
>>>>> wrong lba access.
>>>>
>>>> Delivering f2fs_get_sum_page()'s return value needs a lot of codes change, I think
>>>> we can just zeroing sum_page in error case, as we have already shutdown f2fs via
>>>> calling f2fs_stop_checkpoint(), then f2fs_cp_error() will stop all updates to
>>>> filesystem data including summary pages.
>>>
>>> That sounds like one solution tho, I'm afraid of getting another panic by
>>> wrong zero'ed summary page.
>>
>> What case do you mean? maybe I missed some corner cases?
> 
> I sent v2 to fix syzbot issue, which fixes wrong use of
> f2fs_get_meta_page_nofail.

I agreed to fix that case, however we may encounter deadloop in other
places where we call f2fs_get_meta_page_nofail()? like the case that
filesystem will always see EIO after we shutdown device via dmflakey?

Thanks,

> 
>>
>> Thanks,
>>
>>>
>>>>
>>>> Thoughts?
>>>>
>>>> Thanks,
>>>>
>>>>>
>>>>>>
>>>>>> - Eric
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Linux-f2fs-devel mailing list
>>>>> Linux-f2fs-devel@lists.sourceforge.net
>>>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
>>>>> .
>>>>>
>>> .
>>>
> .
> 


_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Re: [f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[jaegeuk]

On 10/09, Chao Yu wrote:
> On 2020/10/9 12:32, jaegeuk@kernel.org wrote:
> > On 10/09, Chao Yu wrote:
> > > On 2020/10/9 9:50, jaegeuk@kernel.org wrote:
> > > > On 10/09, Chao Yu wrote:
> > > > > On 2020/10/8 5:53, jaegeuk@kernel.org wrote:
> > > > > > On 10/07, Eric Biggers wrote:
> > > > > > > [moved linux-fsdevel to Bcc]
> > > > > > > 
> > > > > > > On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
> > > > > > > > Hello,
> > > > > > > > 
> > > > > > > > syzbot found the following issue on:
> > > > > > > > 
> > > > > > > > HEAD commit:    a804ab08 Add linux-next specific files for 20201006
> > > > > > > > git tree:       linux-next
> > > > > > > > console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
> > > > > > > > kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
> > > > > > > > dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
> > > > > > > > compiler:       gcc (GCC) 10.1.0-syz 20200507
> > > > > > > > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
> > > > > > > > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
> > > > > > > > 
> > > > > > > > The issue was bisected to:
> > > > > > > > 
> > > > > > > > commit eede846af512572b1f30b34f9889d7df64c017d4
> > > > > > > > Author: Jaegeuk Kim <jaegeuk@kernel.org>
> > > > > > > > Date:   Fri Oct 2 21:17:35 2020 +0000
> > > > > > > > 
> > > > > > > >        f2fs: f2fs_get_meta_page_nofail should not be failed
> > > > > > > > 
> > > > > > > 
> > > > > > > Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
> > > > > > > if the requested page is beyond the end of the device.
> > > > > > 
> > > > > > Yes, that will go infinite loop. Otherwise, it will trigger a panic during
> > > > > > the device reboot. Let me think how to avoid that before trying to get the
> > > > > > wrong lba access.
> > > > > 
> > > > > Delivering f2fs_get_sum_page()'s return value needs a lot of codes change, I think
> > > > > we can just zeroing sum_page in error case, as we have already shutdown f2fs via
> > > > > calling f2fs_stop_checkpoint(), then f2fs_cp_error() will stop all updates to
> > > > > filesystem data including summary pages.
> > > > 
> > > > That sounds like one solution tho, I'm afraid of getting another panic by
> > > > wrong zero'ed summary page.
> > > 
> > > What case do you mean? maybe I missed some corner cases?
> > 
> > I sent v2 to fix syzbot issue, which fixes wrong use of
> > f2fs_get_meta_page_nofail.
> 
> I agreed to fix that case, however we may encounter deadloop in other
> places where we call f2fs_get_meta_page_nofail()? like the case that
> filesystem will always see EIO after we shutdown device via dmflakey?

We may need another option to deal with this. At least, however, it's literally
_nofail function which should guarantee no error, instead of hiding the error
with zero'ed page.

> 
> Thanks,
> 
> > 
> > > 
> > > Thanks,
> > > 
> > > > 
> > > > > 
> > > > > Thoughts?
> > > > > 
> > > > > Thanks,
> > > > > 
> > > > > > 
> > > > > > > 
> > > > > > > - Eric
> > > > > > 
> > > > > > 
> > > > > > _______________________________________________
> > > > > > Linux-f2fs-devel mailing list
> > > > > > Linux-f2fs-devel@lists.sourceforge.net
> > > > > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> > > > > > .
> > > > > > 
> > > > .
> > > > 
> > .
> > 

Re: [f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[jaegeuk]

On 10/09, Chao Yu wrote:
> On 2020/10/9 12:32, jaegeuk@kernel.org wrote:
> > On 10/09, Chao Yu wrote:
> > > On 2020/10/9 9:50, jaegeuk@kernel.org wrote:
> > > > On 10/09, Chao Yu wrote:
> > > > > On 2020/10/8 5:53, jaegeuk@kernel.org wrote:
> > > > > > On 10/07, Eric Biggers wrote:
> > > > > > > [moved linux-fsdevel to Bcc]
> > > > > > > 
> > > > > > > On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
> > > > > > > > Hello,
> > > > > > > > 
> > > > > > > > syzbot found the following issue on:
> > > > > > > > 
> > > > > > > > HEAD commit:    a804ab08 Add linux-next specific files for 20201006
> > > > > > > > git tree:       linux-next
> > > > > > > > console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
> > > > > > > > kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
> > > > > > > > dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
> > > > > > > > compiler:       gcc (GCC) 10.1.0-syz 20200507
> > > > > > > > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
> > > > > > > > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
> > > > > > > > 
> > > > > > > > The issue was bisected to:
> > > > > > > > 
> > > > > > > > commit eede846af512572b1f30b34f9889d7df64c017d4
> > > > > > > > Author: Jaegeuk Kim <jaegeuk@kernel.org>
> > > > > > > > Date:   Fri Oct 2 21:17:35 2020 +0000
> > > > > > > > 
> > > > > > > >        f2fs: f2fs_get_meta_page_nofail should not be failed
> > > > > > > > 
> > > > > > > 
> > > > > > > Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
> > > > > > > if the requested page is beyond the end of the device.
> > > > > > 
> > > > > > Yes, that will go infinite loop. Otherwise, it will trigger a panic during
> > > > > > the device reboot. Let me think how to avoid that before trying to get the
> > > > > > wrong lba access.
> > > > > 
> > > > > Delivering f2fs_get_sum_page()'s return value needs a lot of codes change, I think
> > > > > we can just zeroing sum_page in error case, as we have already shutdown f2fs via
> > > > > calling f2fs_stop_checkpoint(), then f2fs_cp_error() will stop all updates to
> > > > > filesystem data including summary pages.
> > > > 
> > > > That sounds like one solution tho, I'm afraid of getting another panic by
> > > > wrong zero'ed summary page.
> > > 
> > > What case do you mean? maybe I missed some corner cases?
> > 
> > I sent v2 to fix syzbot issue, which fixes wrong use of
> > f2fs_get_meta_page_nofail.
> 
> I agreed to fix that case, however we may encounter deadloop in other
> places where we call f2fs_get_meta_page_nofail()? like the case that
> filesystem will always see EIO after we shutdown device via dmflakey?

We may need another option to deal with this. At least, however, it's literally
_nofail function which should guarantee no error, instead of hiding the error
with zero'ed page.

> 
> Thanks,
> 
> > 
> > > 
> > > Thanks,
> > > 
> > > > 
> > > > > 
> > > > > Thoughts?
> > > > > 
> > > > > Thanks,
> > > > > 
> > > > > > 
> > > > > > > 
> > > > > > > - Eric
> > > > > > 
> > > > > > 
> > > > > > _______________________________________________
> > > > > > Linux-f2fs-devel mailing list
> > > > > > Linux-f2fs-devel@lists.sourceforge.net
> > > > > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> > > > > > .
> > > > > > 
> > > > .
> > > > 
> > .
> > 


_______________________________________________
Linux-f2fs-devel mailing list
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https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Re: [f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[Chao Yu]

Jaegeuk,

I guess you missed sending last applied patch to mailing list?

Thanks,

On 2020/10/9 22:56, jaegeuk@kernel.org wrote:
> On 10/09, Chao Yu wrote:
>> On 2020/10/9 12:32, jaegeuk@kernel.org wrote:
>>> On 10/09, Chao Yu wrote:
>>>> On 2020/10/9 9:50, jaegeuk@kernel.org wrote:
>>>>> On 10/09, Chao Yu wrote:
>>>>>> On 2020/10/8 5:53, jaegeuk@kernel.org wrote:
>>>>>>> On 10/07, Eric Biggers wrote:
>>>>>>>> [moved linux-fsdevel to Bcc]
>>>>>>>>
>>>>>>>> On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
>>>>>>>>> Hello,
>>>>>>>>>
>>>>>>>>> syzbot found the following issue on:
>>>>>>>>>
>>>>>>>>> HEAD commit:    a804ab08 Add linux-next specific files for 20201006
>>>>>>>>> git tree:       linux-next
>>>>>>>>> console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
>>>>>>>>> kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
>>>>>>>>> dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
>>>>>>>>> compiler:       gcc (GCC) 10.1.0-syz 20200507
>>>>>>>>> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
>>>>>>>>> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
>>>>>>>>>
>>>>>>>>> The issue was bisected to:
>>>>>>>>>
>>>>>>>>> commit eede846af512572b1f30b34f9889d7df64c017d4
>>>>>>>>> Author: Jaegeuk Kim <jaegeuk@kernel.org>
>>>>>>>>> Date:   Fri Oct 2 21:17:35 2020 +0000
>>>>>>>>>
>>>>>>>>>         f2fs: f2fs_get_meta_page_nofail should not be failed
>>>>>>>>>
>>>>>>>>
>>>>>>>> Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
>>>>>>>> if the requested page is beyond the end of the device.
>>>>>>>
>>>>>>> Yes, that will go infinite loop. Otherwise, it will trigger a panic during
>>>>>>> the device reboot. Let me think how to avoid that before trying to get the
>>>>>>> wrong lba access.
>>>>>>
>>>>>> Delivering f2fs_get_sum_page()'s return value needs a lot of codes change, I think
>>>>>> we can just zeroing sum_page in error case, as we have already shutdown f2fs via
>>>>>> calling f2fs_stop_checkpoint(), then f2fs_cp_error() will stop all updates to
>>>>>> filesystem data including summary pages.
>>>>>
>>>>> That sounds like one solution tho, I'm afraid of getting another panic by
>>>>> wrong zero'ed summary page.
>>>>
>>>> What case do you mean? maybe I missed some corner cases?
>>>
>>> I sent v2 to fix syzbot issue, which fixes wrong use of
>>> f2fs_get_meta_page_nofail.
>>
>> I agreed to fix that case, however we may encounter deadloop in other
>> places where we call f2fs_get_meta_page_nofail()? like the case that
>> filesystem will always see EIO after we shutdown device via dmflakey?
> 
> We may need another option to deal with this. At least, however, it's literally
> _nofail function which should guarantee no error, instead of hiding the error
> with zero'ed page.
> 
>>
>> Thanks,
>>
>>>
>>>>
>>>> Thanks,
>>>>
>>>>>
>>>>>>
>>>>>> Thoughts?
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>> - Eric
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Linux-f2fs-devel mailing list
>>>>>>> Linux-f2fs-devel@lists.sourceforge.net
>>>>>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
>>>>>>> .
>>>>>>>
>>>>> .
>>>>>
>>> .
>>>
> .
> 

Re: [f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[Chao Yu]

Jaegeuk,

I guess you missed sending last applied patch to mailing list?

Thanks,

On 2020/10/9 22:56, jaegeuk@kernel.org wrote:
> On 10/09, Chao Yu wrote:
>> On 2020/10/9 12:32, jaegeuk@kernel.org wrote:
>>> On 10/09, Chao Yu wrote:
>>>> On 2020/10/9 9:50, jaegeuk@kernel.org wrote:
>>>>> On 10/09, Chao Yu wrote:
>>>>>> On 2020/10/8 5:53, jaegeuk@kernel.org wrote:
>>>>>>> On 10/07, Eric Biggers wrote:
>>>>>>>> [moved linux-fsdevel to Bcc]
>>>>>>>>
>>>>>>>> On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
>>>>>>>>> Hello,
>>>>>>>>>
>>>>>>>>> syzbot found the following issue on:
>>>>>>>>>
>>>>>>>>> HEAD commit:    a804ab08 Add linux-next specific files for 20201006
>>>>>>>>> git tree:       linux-next
>>>>>>>>> console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
>>>>>>>>> kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
>>>>>>>>> dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
>>>>>>>>> compiler:       gcc (GCC) 10.1.0-syz 20200507
>>>>>>>>> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
>>>>>>>>> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
>>>>>>>>>
>>>>>>>>> The issue was bisected to:
>>>>>>>>>
>>>>>>>>> commit eede846af512572b1f30b34f9889d7df64c017d4
>>>>>>>>> Author: Jaegeuk Kim <jaegeuk@kernel.org>
>>>>>>>>> Date:   Fri Oct 2 21:17:35 2020 +0000
>>>>>>>>>
>>>>>>>>>         f2fs: f2fs_get_meta_page_nofail should not be failed
>>>>>>>>>
>>>>>>>>
>>>>>>>> Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
>>>>>>>> if the requested page is beyond the end of the device.
>>>>>>>
>>>>>>> Yes, that will go infinite loop. Otherwise, it will trigger a panic during
>>>>>>> the device reboot. Let me think how to avoid that before trying to get the
>>>>>>> wrong lba access.
>>>>>>
>>>>>> Delivering f2fs_get_sum_page()'s return value needs a lot of codes change, I think
>>>>>> we can just zeroing sum_page in error case, as we have already shutdown f2fs via
>>>>>> calling f2fs_stop_checkpoint(), then f2fs_cp_error() will stop all updates to
>>>>>> filesystem data including summary pages.
>>>>>
>>>>> That sounds like one solution tho, I'm afraid of getting another panic by
>>>>> wrong zero'ed summary page.
>>>>
>>>> What case do you mean? maybe I missed some corner cases?
>>>
>>> I sent v2 to fix syzbot issue, which fixes wrong use of
>>> f2fs_get_meta_page_nofail.
>>
>> I agreed to fix that case, however we may encounter deadloop in other
>> places where we call f2fs_get_meta_page_nofail()? like the case that
>> filesystem will always see EIO after we shutdown device via dmflakey?
> 
> We may need another option to deal with this. At least, however, it's literally
> _nofail function which should guarantee no error, instead of hiding the error
> with zero'ed page.
> 
>>
>> Thanks,
>>
>>>
>>>>
>>>> Thanks,
>>>>
>>>>>
>>>>>>
>>>>>> Thoughts?
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>> - Eric
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Linux-f2fs-devel mailing list
>>>>>>> Linux-f2fs-devel@lists.sourceforge.net
>>>>>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
>>>>>>> .
>>>>>>>
>>>>> .
>>>>>
>>> .
>>>
> .
> 


_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Re: [f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[jaegeuk]

On 10/13, Chao Yu wrote:
> Jaegeuk,
> 
> I guess you missed sending last applied patch to mailing list?

I was testing locally and supposed to post it soon before pull request. Putting
it in -dev can give some soak time in -next.

No worries.

Thanks,

> 
> Thanks,
> 
> On 2020/10/9 22:56, jaegeuk@kernel.org wrote:
> > On 10/09, Chao Yu wrote:
> > > On 2020/10/9 12:32, jaegeuk@kernel.org wrote:
> > > > On 10/09, Chao Yu wrote:
> > > > > On 2020/10/9 9:50, jaegeuk@kernel.org wrote:
> > > > > > On 10/09, Chao Yu wrote:
> > > > > > > On 2020/10/8 5:53, jaegeuk@kernel.org wrote:
> > > > > > > > On 10/07, Eric Biggers wrote:
> > > > > > > > > [moved linux-fsdevel to Bcc]
> > > > > > > > > 
> > > > > > > > > On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
> > > > > > > > > > Hello,
> > > > > > > > > > 
> > > > > > > > > > syzbot found the following issue on:
> > > > > > > > > > 
> > > > > > > > > > HEAD commit:    a804ab08 Add linux-next specific files for 20201006
> > > > > > > > > > git tree:       linux-next
> > > > > > > > > > console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
> > > > > > > > > > kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
> > > > > > > > > > dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
> > > > > > > > > > compiler:       gcc (GCC) 10.1.0-syz 20200507
> > > > > > > > > > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
> > > > > > > > > > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
> > > > > > > > > > 
> > > > > > > > > > The issue was bisected to:
> > > > > > > > > > 
> > > > > > > > > > commit eede846af512572b1f30b34f9889d7df64c017d4
> > > > > > > > > > Author: Jaegeuk Kim <jaegeuk@kernel.org>
> > > > > > > > > > Date:   Fri Oct 2 21:17:35 2020 +0000
> > > > > > > > > > 
> > > > > > > > > >         f2fs: f2fs_get_meta_page_nofail should not be failed
> > > > > > > > > > 
> > > > > > > > > 
> > > > > > > > > Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
> > > > > > > > > if the requested page is beyond the end of the device.
> > > > > > > > 
> > > > > > > > Yes, that will go infinite loop. Otherwise, it will trigger a panic during
> > > > > > > > the device reboot. Let me think how to avoid that before trying to get the
> > > > > > > > wrong lba access.
> > > > > > > 
> > > > > > > Delivering f2fs_get_sum_page()'s return value needs a lot of codes change, I think
> > > > > > > we can just zeroing sum_page in error case, as we have already shutdown f2fs via
> > > > > > > calling f2fs_stop_checkpoint(), then f2fs_cp_error() will stop all updates to
> > > > > > > filesystem data including summary pages.
> > > > > > 
> > > > > > That sounds like one solution tho, I'm afraid of getting another panic by
> > > > > > wrong zero'ed summary page.
> > > > > 
> > > > > What case do you mean? maybe I missed some corner cases?
> > > > 
> > > > I sent v2 to fix syzbot issue, which fixes wrong use of
> > > > f2fs_get_meta_page_nofail.
> > > 
> > > I agreed to fix that case, however we may encounter deadloop in other
> > > places where we call f2fs_get_meta_page_nofail()? like the case that
> > > filesystem will always see EIO after we shutdown device via dmflakey?
> > 
> > We may need another option to deal with this. At least, however, it's literally
> > _nofail function which should guarantee no error, instead of hiding the error
> > with zero'ed page.
> > 
> > > 
> > > Thanks,
> > > 
> > > > 
> > > > > 
> > > > > Thanks,
> > > > > 
> > > > > > 
> > > > > > > 
> > > > > > > Thoughts?
> > > > > > > 
> > > > > > > Thanks,
> > > > > > > 
> > > > > > > > 
> > > > > > > > > 
> > > > > > > > > - Eric
> > > > > > > > 
> > > > > > > > 
> > > > > > > > _______________________________________________
> > > > > > > > Linux-f2fs-devel mailing list
> > > > > > > > Linux-f2fs-devel@lists.sourceforge.net
> > > > > > > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> > > > > > > > .
> > > > > > > > 
> > > > > > .
> > > > > > 
> > > > .
> > > > 
> > .
> > 

Re: [f2fs-dev] [f2fs bug] infinite loop in f2fs_get_meta_page_nofail()

[jaegeuk]

On 10/13, Chao Yu wrote:
> Jaegeuk,
> 
> I guess you missed sending last applied patch to mailing list?

I was testing locally and supposed to post it soon before pull request. Putting
it in -dev can give some soak time in -next.

No worries.

Thanks,

> 
> Thanks,
> 
> On 2020/10/9 22:56, jaegeuk@kernel.org wrote:
> > On 10/09, Chao Yu wrote:
> > > On 2020/10/9 12:32, jaegeuk@kernel.org wrote:
> > > > On 10/09, Chao Yu wrote:
> > > > > On 2020/10/9 9:50, jaegeuk@kernel.org wrote:
> > > > > > On 10/09, Chao Yu wrote:
> > > > > > > On 2020/10/8 5:53, jaegeuk@kernel.org wrote:
> > > > > > > > On 10/07, Eric Biggers wrote:
> > > > > > > > > [moved linux-fsdevel to Bcc]
> > > > > > > > > 
> > > > > > > > > On Wed, Oct 07, 2020 at 02:18:19AM -0700, syzbot wrote:
> > > > > > > > > > Hello,
> > > > > > > > > > 
> > > > > > > > > > syzbot found the following issue on:
> > > > > > > > > > 
> > > > > > > > > > HEAD commit:    a804ab08 Add linux-next specific files for 20201006
> > > > > > > > > > git tree:       linux-next
> > > > > > > > > > console output: https://syzkaller.appspot.com/x/log.txt?x=17fe30bf900000
> > > > > > > > > > kernel config:  https://syzkaller.appspot.com/x/.config?x=26c1b4cc4a62ccb
> > > > > > > > > > dashboard link: https://syzkaller.appspot.com/bug?extid=ee250ac8137be41d7b13
> > > > > > > > > > compiler:       gcc (GCC) 10.1.0-syz 20200507
> > > > > > > > > > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1336413b900000
> > > > > > > > > > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12f7392b900000
> > > > > > > > > > 
> > > > > > > > > > The issue was bisected to:
> > > > > > > > > > 
> > > > > > > > > > commit eede846af512572b1f30b34f9889d7df64c017d4
> > > > > > > > > > Author: Jaegeuk Kim <jaegeuk@kernel.org>
> > > > > > > > > > Date:   Fri Oct 2 21:17:35 2020 +0000
> > > > > > > > > > 
> > > > > > > > > >         f2fs: f2fs_get_meta_page_nofail should not be failed
> > > > > > > > > > 
> > > > > > > > > 
> > > > > > > > > Jaegeuk, it looks like the loop you added in the above commit doesn't terminate
> > > > > > > > > if the requested page is beyond the end of the device.
> > > > > > > > 
> > > > > > > > Yes, that will go infinite loop. Otherwise, it will trigger a panic during
> > > > > > > > the device reboot. Let me think how to avoid that before trying to get the
> > > > > > > > wrong lba access.
> > > > > > > 
> > > > > > > Delivering f2fs_get_sum_page()'s return value needs a lot of codes change, I think
> > > > > > > we can just zeroing sum_page in error case, as we have already shutdown f2fs via
> > > > > > > calling f2fs_stop_checkpoint(), then f2fs_cp_error() will stop all updates to
> > > > > > > filesystem data including summary pages.
> > > > > > 
> > > > > > That sounds like one solution tho, I'm afraid of getting another panic by
> > > > > > wrong zero'ed summary page.
> > > > > 
> > > > > What case do you mean? maybe I missed some corner cases?
> > > > 
> > > > I sent v2 to fix syzbot issue, which fixes wrong use of
> > > > f2fs_get_meta_page_nofail.
> > > 
> > > I agreed to fix that case, however we may encounter deadloop in other
> > > places where we call f2fs_get_meta_page_nofail()? like the case that
> > > filesystem will always see EIO after we shutdown device via dmflakey?
> > 
> > We may need another option to deal with this. At least, however, it's literally
> > _nofail function which should guarantee no error, instead of hiding the error
> > with zero'ed page.
> > 
> > > 
> > > Thanks,
> > > 
> > > > 
> > > > > 
> > > > > Thanks,
> > > > > 
> > > > > > 
> > > > > > > 
> > > > > > > Thoughts?
> > > > > > > 
> > > > > > > Thanks,
> > > > > > > 
> > > > > > > > 
> > > > > > > > > 
> > > > > > > > > - Eric
> > > > > > > > 
> > > > > > > > 
> > > > > > > > _______________________________________________
> > > > > > > > Linux-f2fs-devel mailing list
> > > > > > > > Linux-f2fs-devel@lists.sourceforge.net
> > > > > > > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> > > > > > > > .
> > > > > > > > 
> > > > > > .
> > > > > > 
> > > > .
> > > > 
> > .
> > 


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