Re: BUG: unable to handle kernel paging request in workingset_age_nonresident

[Dmitry Vyukov]

On Tue, Dec 1, 2020 at 8:40 AM syzbot
<syzbot+a59e7ceb87a83c5233df@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    c6b11acc Add linux-next specific files for 20201130
> git tree:       linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=114b94e9500000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=b5e03844e9b34d37
> dashboard link: https://syzkaller.appspot.com/bug?extid=a59e7ceb87a83c5233df
> compiler:       gcc (GCC) 10.1.0-syz 20200507
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=150fed8b500000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1726291d500000
>
> The issue was bisected to:
>
> commit 76761ffa9ea1ddca78e817bf7eec5fcb0378a00c
> Author: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx>
> Date:   Sun Nov 29 23:58:06 2020 +0000
>
>     mm/memcg: bail out early when !memcg in mem_cgroup_lruvec

This patch was removed from linux-next, so let's close the report:

#syz invalid


> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=122ff445500000
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=112ff445500000
> console output: https://syzkaller.appspot.com/x/log.txt?x=162ff445500000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+a59e7ceb87a83c5233df@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: 76761ffa9ea1 ("mm/memcg: bail out early when !memcg in mem_cgroup_lruvec")
>
> BUG: unable to handle page fault for address: ffffffff81417c79
> #PF: supervisor write access in kernel mode
> #PF: error_code(0x0003) - permissions violation
> PGD b08f067 P4D b08f067 PUD b090063 PMD 14001e1
> Oops: 0003 [#1] PREEMPT SMP KASAN
> CPU: 1 PID: 8503 Comm: syz-executor118 Not tainted 5.10.0-rc5-next-20201130-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> RIP: 0010:mem_cgroup_lruvec include/linux/memcontrol.h:630 [inline]
> RIP: 0010:parent_lruvec include/linux/memcontrol.h:1560 [inline]
> RIP: 0010:workingset_age_nonresident+0x179/0x1c0 mm/workingset.c:242
> Code: 85 db 0f 85 c8 fe ff ff 5b 5d 41 5c 41 5d 41 5e 41 5f e9 6a 67 cf ff e8 65 67 cf ff 49 8d 9d 18 4d 00 00 eb b3 e8 57 67 cf ff <4c> 89 ab c0 00 00 00 eb c7 e8 69 35 12 00 e9 d3 fe ff ff e8 5f 35
> RSP: 0018:ffffc9000112f4c0 EFLAGS: 00010093
> RAX: 0000000000000000 RBX: ffffffff81417bb9 RCX: 0000000000000000
> RDX: ffff88801eee5040 RSI: ffffffff81a159f9 RDI: ffffffff81417c79
> RBP: dffffc0000000000 R08: 0000000000000001 R09: ffff88813ffffdbf
> R10: ffffed1027ffffb7 R11: 0000000000000000 R12: ffffffff8e7911d0
> R13: ffff88813fffb000 R14: 0000000000000001 R15: ffffffff8e7910b0
> FS:  0000000002581880(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: ffffffff81417c79 CR3: 0000000013a2f000 CR4: 00000000001506e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  workingset_eviction+0x452/0x9b0 mm/workingset.c:266
>  __remove_mapping+0x867/0xd20 mm/vmscan.c:927
>  shrink_page_list+0x246a/0x5e80 mm/vmscan.c:1431
>  reclaim_pages+0x3e2/0xcd0 mm/vmscan.c:2148
>  madvise_cold_or_pageout_pte_range+0x1615/0x2880 mm/madvise.c:473
>  walk_pmd_range mm/pagewalk.c:89 [inline]
>  walk_pud_range mm/pagewalk.c:160 [inline]
>  walk_p4d_range mm/pagewalk.c:193 [inline]
>  walk_pgd_range mm/pagewalk.c:229 [inline]
>  __walk_page_range+0xda4/0x1e20 mm/pagewalk.c:331
>  walk_page_range+0x1be/0x450 mm/pagewalk.c:427
>  madvise_pageout_page_range mm/madvise.c:526 [inline]
>  madvise_pageout+0x21b/0x390 mm/madvise.c:562
>  madvise_vma mm/madvise.c:943 [inline]
>  do_madvise.part.0+0x9f2/0x1ed0 mm/madvise.c:1142
>  do_madvise mm/madvise.c:1168 [inline]
>  __do_sys_madvise mm/madvise.c:1168 [inline]
>  __se_sys_madvise mm/madvise.c:1166 [inline]
>  __x64_sys_madvise+0x113/0x150 mm/madvise.c:1166
>  do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
>  entry_SYSCALL_64_after_hwframe+0x44/0xa9
> RIP: 0033:0x440279
> Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
> RSP: 002b:00007ffe7c1ab298 EFLAGS: 00000246 ORIG_RAX: 000000000000001c
> RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440279
> RDX: 0000000000000015 RSI: 0000000000600003 RDI: 0000000020000000
> RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000401a80
> R13: 0000000000401b10 R14: 0000000000000000 R15: 0000000000000000
> Modules linked in:
> CR2: ffffffff81417c79
> ---[ end trace 89bcebda47215cf6 ]---
> RIP: 0010:mem_cgroup_lruvec include/linux/memcontrol.h:630 [inline]
> RIP: 0010:parent_lruvec include/linux/memcontrol.h:1560 [inline]
> RIP: 0010:workingset_age_nonresident+0x179/0x1c0 mm/workingset.c:242
> Code: 85 db 0f 85 c8 fe ff ff 5b 5d 41 5c 41 5d 41 5e 41 5f e9 6a 67 cf ff e8 65 67 cf ff 49 8d 9d 18 4d 00 00 eb b3 e8 57 67 cf ff <4c> 89 ab c0 00 00 00 eb c7 e8 69 35 12 00 e9 d3 fe ff ff e8 5f 35
> RSP: 0018:ffffc9000112f4c0 EFLAGS: 00010093
> RAX: 0000000000000000 RBX: ffffffff81417bb9 RCX: 0000000000000000
> RDX: ffff88801eee5040 RSI: ffffffff81a159f9 RDI: ffffffff81417c79
> RBP: dffffc0000000000 R08: 0000000000000001 R09: ffff88813ffffdbf
> R10: ffffed1027ffffb7 R11: 0000000000000000 R12: ffffffff8e7911d0
> R13: ffff88813fffb000 R14: 0000000000000001 R15: ffffffff8e7910b0
> FS:  0000000002581880(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: ffffffff81417c79 CR3: 0000000013a2f000 CR4: 00000000001506e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>
>
> ---
> 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@xxxxxxxxxxxxxxxx.
>
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> 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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