On Mon, May 11, 2020 at 11:55:16PM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following crash on:
This is like
https://lore.kernel.org/linux-nfs/5016dd05a5e6b...@google.com/
in that we're discovering the drc is corrupt while destroying it.
I don't see the problem yet.
--b.
>
> HEAD commit:6e7f2eac Merge tag 'arm64-fixes' of git://git.kernel.org/p..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=1456703410
> kernel config: https://syzkaller.appspot.com/x/.config?x=b0212dbee046bc1f
> dashboard link: https://syzkaller.appspot.com/bug?extid=a29df412692980277f9d
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
>
> Unfortunately, I don't have any reproducer for this crash yet.
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+a29df412692980277...@syzkaller.appspotmail.com
>
> general protection fault, probably for non-canonical address
> 0xdc02: [#1] PREEMPT SMP KASAN
> KASAN: null-ptr-deref in range [0x0010-0x0017]
> CPU: 0 PID: 27932 Comm: kworker/u4:4 Not tainted 5.7.0-rc4-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> Workqueue: netns cleanup_net
> RIP: 0010:nfsd_reply_cache_free_locked+0x2d/0x380 fs/nfsd/nfscache.c:122
> Code: 56 41 55 41 54 49 89 fc 55 48 89 f5 53 48 89 d3 e8 08 c0 2f ff 48 8d 7d
> 61 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa
> 83 e2 07 38 d0 7f 08 84 c0 0f 85 a7 02 00 00
> RSP: 0018:c90008bb7b70 EFLAGS: 00010202
> RAX: dc00 RBX: 88826000 RCX: dc00
> RDX: 0002 RSI: 82436ea8 RDI: 0011
> RBP: ffb0 R08: 888093792400 R09: fbfff185cf3e
> R10: 8c2e79ef R11: fbfff185cf3d R12: 88800010
> R13: 88800018 R14: R15: 88800010
> FS: () GS:8880ae60() knlGS:
> CS: 0010 DS: ES: CR0: 80050033
> CR2: 001b2c531000 CR3: 685a2000 CR4: 001426f0
> DR0: DR1: DR2:
> DR3: DR6: fffe0ff0 DR7: 0400
> Call Trace:
> nfsd_reply_cache_shutdown+0x150/0x350 fs/nfsd/nfscache.c:203
> nfsd_exit_net+0x189/0x4c0 fs/nfsd/nfsctl.c:1504
> ops_exit_list.isra.0+0xa8/0x150 net/core/net_namespace.c:186
> cleanup_net+0x511/0xa50 net/core/net_namespace.c:603
> process_one_work+0x965/0x16a0 kernel/workqueue.c:2268
> worker_thread+0x96/0xe20 kernel/workqueue.c:2414
> kthread+0x388/0x470 kernel/kthread.c:268
> ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
> Modules linked in:
> ---[ end trace 54f06072fc6a1afa ]---
> RIP: 0010:nfsd_reply_cache_free_locked+0x2d/0x380 fs/nfsd/nfscache.c:122
> Code: 56 41 55 41 54 49 89 fc 55 48 89 f5 53 48 89 d3 e8 08 c0 2f ff 48 8d 7d
> 61 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa
> 83 e2 07 38 d0 7f 08 84 c0 0f 85 a7 02 00 00
> RSP: 0018:c90008bb7b70 EFLAGS: 00010202
> RAX: dc00 RBX: 88826000 RCX: dc00
> RDX: 0002 RSI: 82436ea8 RDI: 0011
> RBP: ffb0 R08: 888093792400 R09: fbfff185cf3e
> R10: 8c2e79ef R11: fbfff185cf3d R12: 88800010
> R13: 88800018 R14: R15: 88800010
> FS: () GS:8880ae60() knlGS:
> CS: 0010 DS: ES: CR0: 80050033
> CR2: 001b2c531000 CR3: 94cfb000 CR4: 001426f0
> DR0: DR1: DR2:
> DR3: DR6: fffe0ff0 DR7: 0400
>
>
> ---
> This bug is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
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>
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