syzbot


BUG: soft lockup in br_ip6_multicast_query_expired

Status: upstream: reported C repro on 2021/09/16 13:02
Reported-by: syzbot+f1358d82a4dee12ee4df@syzkaller.appspotmail.com
First crash: 1192d, last: 1077d
Fix bisection: failed (error log, bisect log)
  

Sample crash report:
watchdog: BUG: soft lockup - CPU#1 stuck for 23s! [ksoftirqd/1:18]
Modules linked in:
irq event stamp: 10784237
hardirqs last  enabled at (10784236): [<ffffffff81980aba>] slab_alloc_node mm/slab.c:3334 [inline]
hardirqs last  enabled at (10784236): [<ffffffff81980aba>] kmem_cache_alloc_node+0x2da/0x3b0 mm/slab.c:3647
hardirqs last disabled at (10784237): [<ffffffff81003d00>] trace_hardirqs_off_thunk+0x1a/0x1c
softirqs last  enabled at (2681798): [<ffffffff88400678>] __do_softirq+0x678/0x980 kernel/softirq.c:318
softirqs last disabled at (2681823): [<ffffffff81392417>] run_ksoftirqd+0x57/0x110 kernel/softirq.c:653
CPU: 1 PID: 18 Comm: ksoftirqd/1 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:26 [inline]
RIP: 0010:__orc_find+0x83/0xf0 arch/x86/kernel/unwind_orc.c:48
Code: 01 d0 48 d1 f8 48 8d 5c 85 00 48 89 d8 48 c1 e8 03 42 0f b6 14 38 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 48 48 63 03 <48> 01 d8 48 39 c1 73 b0 4c 8d 63 fc 49 39 ec 73 b3 4d 29 ee 49 c1
RSP: 0018:ffff8880b5acf488 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: fffffffffbaacdba RBX: ffffffff8b7dc444 RCX: ffffffff872892a5
RDX: 0000000000000000 RSI: ffffffff8c0102d8 RDI: ffffffff8b7dc444
RBP: ffffffff8b7dc444 R08: 0000000000000000 R09: ffffffff8c0102d8
R10: ffff8880b5acf65f R11: 0000000000074071 R12: ffffffff8b7dc444
R13: ffffffff8b7dc444 R14: ffffffff8b7dc444 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005596285bdaa0 CR3: 0000000009e6d000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 orc_find arch/x86/kernel/unwind_orc.c:159 [inline]
 unwind_next_frame+0x339/0x1400 arch/x86/kernel/unwind_orc.c:422
 __save_stack_trace+0x9f/0x190 arch/x86/kernel/stacktrace.c:44
 save_stack mm/kasan/kasan.c:448 [inline]
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:553
 kmem_cache_alloc_node+0x146/0x3b0 mm/slab.c:3649
 __alloc_skb+0x71/0x560 net/core/skbuff.c:193
 __netdev_alloc_skb+0x76/0x460 net/core/skbuff.c:407
 __netdev_alloc_skb_ip_align include/linux/skbuff.h:2700 [inline]
 netdev_alloc_skb_ip_align include/linux/skbuff.h:2710 [inline]
 br_ip6_multicast_alloc_query net/bridge/br_multicast.c:479 [inline]
 br_multicast_alloc_query net/bridge/br_multicast.c:585 [inline]
 __br_multicast_send_query+0x1a7/0x2dc0 net/bridge/br_multicast.c:941
 br_multicast_send_query+0x216/0x3a0 net/bridge/br_multicast.c:988
 br_multicast_query_expired net/bridge/br_multicast.c:1942 [inline]
 br_ip6_multicast_query_expired+0xdc/0x110 net/bridge/br_multicast.c:1958
 call_timer_fn+0x177/0x700 kernel/time/timer.c:1338
 expire_timers+0x243/0x4e0 kernel/time/timer.c:1375
 __run_timers kernel/time/timer.c:1696 [inline]
 run_timer_softirq+0x21c/0x670 kernel/time/timer.c:1709
 __do_softirq+0x265/0x980 kernel/softirq.c:292
 run_ksoftirqd+0x57/0x110 kernel/softirq.c:653
 smpboot_thread_fn+0x655/0x9e0 kernel/smpboot.c:164
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
----------------
Code disassembly (best guess):
   0:	01 d0                	add    %edx,%eax
   2:	48 d1 f8             	sar    %rax
   5:	48 8d 5c 85 00       	lea    0x0(%rbp,%rax,4),%rbx
   a:	48 89 d8             	mov    %rbx,%rax
   d:	48 c1 e8 03          	shr    $0x3,%rax
  11:	42 0f b6 14 38       	movzbl (%rax,%r15,1),%edx
  16:	48 89 d8             	mov    %rbx,%rax
  19:	83 e0 07             	and    $0x7,%eax
  1c:	83 c0 03             	add    $0x3,%eax
  1f:	38 d0                	cmp    %dl,%al
  21:	7c 04                	jl     0x27
  23:	84 d2                	test   %dl,%dl
  25:	75 48                	jne    0x6f
  27:	48 63 03             	movslq (%rbx),%rax
* 2a:	48 01 d8             	add    %rbx,%rax <-- trapping instruction
  2d:	48 39 c1             	cmp    %rax,%rcx
  30:	73 b0                	jae    0xffffffe2
  32:	4c 8d 63 fc          	lea    -0x4(%rbx),%r12
  36:	49 39 ec             	cmp    %rbp,%r12
  39:	73 b3                	jae    0xffffffee
  3b:	4d 29 ee             	sub    %r13,%r14
  3e:	49                   	rex.WB
  3f:	c1                   	.byte 0xc1

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/01/01 15:21 linux-4.19.y 3f8a27f9e27b e1768e9c .config console log report syz C ci2-linux-4-19 BUG: soft lockup in br_ip6_multicast_query_expired
2021/12/20 23:44 linux-4.19.y 3f8a27f9e27b 62bd192b .config console log report syz C ci2-linux-4-19 BUG: soft lockup in br_ip6_multicast_query_expired
2022/01/08 16:37 linux-4.19.y 3f8a27f9e27b 2ca0d385 .config console log report info ci2-linux-4-19 BUG: soft lockup in br_ip6_multicast_query_expired
2022/01/07 19:40 linux-4.19.y 3f8a27f9e27b 2ca0d385 .config console log report info ci2-linux-4-19 BUG: soft lockup in br_ip6_multicast_query_expired
2022/01/02 17:52 linux-4.19.y 3f8a27f9e27b e1768e9c .config console log report info ci2-linux-4-19 BUG: soft lockup in br_ip6_multicast_query_expired
2021/12/19 14:19 linux-4.19.y 3f8a27f9e27b 44068e19 .config console log report info ci2-linux-4-19 BUG: soft lockup in br_ip6_multicast_query_expired
2021/09/17 05:12 linux-4.19.y b172b44fcb17 5b989942 .config console log report info ci2-linux-4-19 BUG: soft lockup in br_ip6_multicast_query_expired
2021/09/16 13:02 linux-4.19.y b172b44fcb17 07e953c1 .config console log report info ci2-linux-4-19 BUG: soft lockup in br_ip6_multicast_query_expired
* Struck through repros no longer work on HEAD.