syzbot


linux-next boot error: BUG: unable to handle kernel paging request in copy_namespaces

Status: fixed on 2023/02/24 13:50
Subsystems: kernel
[Documentation on labels]
Fix commit: 9993a4f989c7 virtio: Revert "virtio: find_vqs() add arg sizes"
First crash: 839d, last: 839d

Sample crash report:
BUG: unable to handle page fault for address: ffffdc0000000013
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 11826067 P4D 11826067 PUD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 55 Comm: kworker/u4:4 Not tainted 6.0.0-rc1-next-20220816-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
Workqueue: events_unbound call_usermodehelper_exec_work
RIP: 0010:copy_namespaces+0xe8/0x480 kernel/nsproxy.c:154
Code: ee 6a 2b 00 45 85 ed 0f 84 d4 01 00 00 e8 20 6e 2b 00 49 8d bf 98 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 42 03 00 00 4d 8b bf 98 00 00 00 e8 82 b9 15 00
RSP: 0000:ffffc90001567900 EFLAGS: 00010a02
RAX: dffffc0000000000 RBX: ffff8880201e0000 RCX: 0000000000000000
RDX: 1fffe00000000013 RSI: ffffffff8150a700 RDI: ffff000000000098
RBP: ffff000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000808100
R13: 0000000000000001 R14: ffff8880201e08a0 R15: ffff000000000000
FS:  0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffdc0000000013 CR3: 000000000bc8e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 copy_process+0x308a/0x7120 kernel/fork.c:2260
 kernel_clone+0xe7/0xab0 kernel/fork.c:2675
 user_mode_thread+0xad/0xe0 kernel/fork.c:2744
 call_usermodehelper_exec_work kernel/umh.c:174 [inline]
 call_usermodehelper_exec_work+0xcc/0x180 kernel/umh.c:160
 process_one_work+0x991/0x1610 kernel/workqueue.c:2312
 worker_thread+0x665/0x1080 kernel/workqueue.c:2459
 kthread+0x2e4/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>
Modules linked in:
CR2: ffffdc0000000013
---[ end trace 0000000000000000 ]---
RIP: 0010:copy_namespaces+0xe8/0x480 kernel/nsproxy.c:154
Code: ee 6a 2b 00 45 85 ed 0f 84 d4 01 00 00 e8 20 6e 2b 00 49 8d bf 98 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 42 03 00 00 4d 8b bf 98 00 00 00 e8 82 b9 15 00
RSP: 0000:ffffc90001567900 EFLAGS: 00010a02
RAX: dffffc0000000000 RBX: ffff8880201e0000 RCX: 0000000000000000
RDX: 1fffe00000000013 RSI: ffffffff8150a700 RDI: ffff000000000098
RBP: ffff000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000808100
R13: 0000000000000001 R14: ffff8880201e08a0 R15: ffff000000000000
FS:  0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffdc0000000013 CR3: 000000000bc8e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	ee                   	out    %al,(%dx)
   1:	6a 2b                	pushq  $0x2b
   3:	00 45 85             	add    %al,-0x7b(%rbp)
   6:	ed                   	in     (%dx),%eax
   7:	0f 84 d4 01 00 00    	je     0x1e1
   d:	e8 20 6e 2b 00       	callq  0x2b6e32
  12:	49 8d bf 98 00 00 00 	lea    0x98(%r15),%rdi
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	48 89 fa             	mov    %rdi,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 42 03 00 00    	jne    0x376
  34:	4d 8b bf 98 00 00 00 	mov    0x98(%r15),%r15
  3b:	e8 82 b9 15 00       	callq  0x15b9c2

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/08/16 04:38 linux-next e1084bacab44 8dfcaa3d .config console log report ci-upstream-linux-next-kasan-gce-root linux-next boot error: BUG: unable to handle kernel paging request in copy_namespaces
* Struck through repros no longer work on HEAD.