general protection fault in nfsd_reply_cache_free

general protection fault in nfsd_reply_cache_free_locked
Status: upstream: reported on 2020/05/12 06:55
Reported-by: syzbot+a29df412692980277f9d@syzkaller.appspotmail.com
First crash: 26d, last: 26d

Sample crash report:

general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
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:ffffc90008bb7b70 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff888000026000 RCX: dffffc0000000000
RDX: 0000000000000002 RSI: ffffffff82436ea8 RDI: 0000000000000011
RBP: ffffffffffffffb0 R08: ffff888093792400 R09: fffffbfff185cf3e
R10: ffffffff8c2e79ef R11: fffffbfff185cf3d R12: ffff888000100000
R13: ffff888000100008 R14: 0000000000000000 R15: ffff888000100000
FS:  0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2c531000 CR3: 00000000685a2000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
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:ffffc90008bb7b70 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff888000026000 RCX: dffffc0000000000
RDX: 0000000000000002 RSI: ffffffff82436ea8 RDI: 0000000000000011
RBP: ffffffffffffffb0 R08: ffff888093792400 R09: fffffbfff185cf3e
R10: ffffffff8c2e79ef R11: fffffbfff185cf3d R12: ffff888000100000
R13: ffff888000100008 R14: 0000000000000000 R15: ffff888000100000
FS:  0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2c531000 CR3: 0000000094cfb000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	Maintainers
ci-upstream-kasan-gce-selinux-root	2020/05/07 23:21	upstream	6e7f2eac	6c70a1c2	.config	log	report			bfields@fieldses.org, chuck.lever@oracle.com, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org