Re: kernel panic: System is deadlocked on memory

[Yafang Shao]

On Wed, Jul 15, 2020 at 12:49 PM syzbot
<syzbot+98be80110b9043885626@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    d31958b3 Add linux-next specific files for 20200710
> git tree:       linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=11a2fe13100000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=3fe4fccb94cbc1a6
> dashboard link: https://syzkaller.appspot.com/bug?extid=98be80110b9043885626
> compiler:       gcc (GCC) 10.1.0-syz 20200507
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=101ec967100000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14a77000900000
>
> The issue was bisected to:
>
> commit e642d9be463d02c735cd99a9a904063324ee03d6
> Author: Yafang Shao <laoar.shao@xxxxxxxxx>
> Date:   Fri Jul 10 04:58:08 2020 +0000
>
>     mm, oom: make the calculation of oom badness more accurate
>
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=1432bd77100000
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=1632bd77100000
> console output: https://syzkaller.appspot.com/x/log.txt?x=1232bd77100000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+98be80110b9043885626@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: e642d9be463d ("mm, oom: make the calculation of oom badness more accurate")
>
> Out of memory and no killable processes...
> Kernel panic - not syncing: System is deadlocked on memory
> CPU: 0 PID: 6810 Comm: syz-executor919 Not tainted 5.8.0-rc4-next-20200710-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+0x18f/0x20d lib/dump_stack.c:118
>  panic+0x2e3/0x75c kernel/panic.c:231
>  out_of_memory mm/oom_kill.c:1106 [inline]
>  out_of_memory.cold+0xa6/0x182 mm/oom_kill.c:1041
>  pagefault_out_of_memory+0x109/0x11c mm/oom_kill.c:1135
>  mm_fault_error+0x123/0x380 arch/x86/mm/fault.c:930
>  do_user_addr_fault+0x5f8/0xbf0 arch/x86/mm/fault.c:1317
>  handle_page_fault arch/x86/mm/fault.c:1351 [inline]
>  exc_page_fault+0xab/0x170 arch/x86/mm/fault.c:1404
>  asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:544
> RIP: 0033:0x40154d
> Code: Bad RIP value.
> RSP: 002b:00007ffddf4649b0 EFLAGS: 00010202
> RAX: 0000000000000001 RBX: 0000000000000000 RCX: fffffffffffffffd
> RDX: 0000000000000001 RSI: 00007ffddf4665e0 RDI: ffffffffffffffff
> RBP: 00007ffddf4665e0 R08: 0000000000000000 R09: 0000000000000001
> R10: 0000000000000064 R11: 0000000000000246 R12: ffffffffffffffff
> R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000000
> 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@xxxxxxxxxxxxxxxxx
>
> 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

Thanks for the report.
This issue has been already fixed by
"mm-oom-make-the-calculation-of-oom-badness-more-accurate-v3", which
is already in the -next tree.


-- 
Thanks
Yafang