syzbot


general protection fault in l2cap_chan_timeout (2)

Status: upstream: reported C repro on 2021/06/23 21:07
Reported-by: syzbot+134361f2dab7d2d9f8a2@syzkaller.appspotmail.com
First crash: 1009d, last: 917d
Fix bisection: failed (error log, bisect log)
  
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in l2cap_chan_timeout (2) bluetooth 1 1037d 1033d 0/26 auto-closed as invalid on 2021/09/23 19:42
upstream general protection fault in l2cap_chan_timeout bluetooth 1 1219d 1215d 0/26 auto-closed as invalid on 2021/03/25 23:40
upstream general protection fault in l2cap_chan_timeout (3) bluetooth C inconclusive inconclusive 5 1d09h 777d 0/26 upstream: reported C repro on 2022/02/10 18:27
linux-4.14 general protection fault in l2cap_chan_timeout 1 1335d 1335d 0/1 auto-closed as invalid on 2020/11/29 23:43
linux-4.19 general protection fault in l2cap_chan_timeout 1 1313d 1313d 0/1 auto-closed as invalid on 2020/12/21 18:33
linux-4.14 general protection fault in l2cap_chan_timeout (2) C 3 404d 769d 0/1 upstream: reported C repro on 2022/02/18 23:43

Sample crash report:
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 8170 Comm: kworker/0:0 Not tainted 4.19.207-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events l2cap_chan_timeout
RIP: 0010:__lock_acquire+0x1eb/0x3ff0 kernel/locking/lockdep.c:3295
Code: 2b 29 00 00 48 81 c4 98 01 00 00 44 89 f8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 b3 2a 00 00 49 81 3e 20 f2 66 8c 0f 84 65 ff ff
RSP: 0018:ffff8880af37f958 EFLAGS: 00010006
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000053 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000074071 R12: 0000000000000000
R13: ffff8880b3b7e080 R14: 0000000000000298 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc374dbc718 CR3: 00000000928c0000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908
 __mutex_lock_common kernel/locking/mutex.c:937 [inline]
 __mutex_lock+0xd7/0x1190 kernel/locking/mutex.c:1078
 l2cap_chan_timeout+0x69/0x2f0 net/bluetooth/l2cap_core.c:416
 process_one_work+0x864/0x1570 kernel/workqueue.c:2153
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Modules linked in:
---[ end trace 92fca598f788abb7 ]---
RIP: 0010:__lock_acquire+0x1eb/0x3ff0 kernel/locking/lockdep.c:3295
Code: 2b 29 00 00 48 81 c4 98 01 00 00 44 89 f8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 b3 2a 00 00 49 81 3e 20 f2 66 8c 0f 84 65 ff ff
RSP: 0018:ffff8880af37f958 EFLAGS: 00010006
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000053 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000074071 R12: 0000000000000000
R13: ffff8880b3b7e080 R14: 0000000000000298 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc374dbc718 CR3: 00000000928c0000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	2b 29                	sub    (%rcx),%ebp
   2:	00 00                	add    %al,(%rax)
   4:	48 81 c4 98 01 00 00 	add    $0x198,%rsp
   b:	44 89 f8             	mov    %r15d,%eax
   e:	5b                   	pop    %rbx
   f:	5d                   	pop    %rbp
  10:	41 5c                	pop    %r12
  12:	41 5d                	pop    %r13
  14:	41 5e                	pop    %r14
  16:	41 5f                	pop    %r15
  18:	c3                   	retq
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	4c 89 f2             	mov    %r14,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 b3 2a 00 00    	jne    0x2ae7
  34:	49 81 3e 20 f2 66 8c 	cmpq   $0xffffffff8c66f220,(%r14)
  3b:	0f                   	.byte 0xf
  3c:	84 65 ff             	test   %ah,-0x1(%rbp)
  3f:	ff                   	.byte 0xff

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/09/23 22:09 linux-4.19.y 2950c9c5e0df 8cac236e .config console log report syz C ci2-linux-4-19 general protection fault in l2cap_chan_timeout
2021/06/23 21:06 linux-4.19.y eb575cd5d7f6 fe4ab389 .config console log report info ci2-linux-4-19 general protection fault in l2cap_chan_timeout
* Struck through repros no longer work on HEAD.