syzbot

 sign-in | mailing list | source | docs
🐞 Open [119]
🐞 Fixed [23]
🐞 Invalid [360]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
💬 Send us feedback

BUG: soft lockup in br_multicast_port_group_expired

Status: auto-obsoleted due to no activity on 2025/02/05 03:41
Reported-by: syzbot+b22a067ccaa408dbecdd@syzkaller.appspotmail.com
First crash: 571d, last: 488d
▶ ▼ Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-1 BUG: soft lockup in br_multicast_port_group_expired 1 3 522d 633d 0/2 auto-obsoleted due to no activity on 2025/01/02 19:42
android-54 BUG: soft lockup in br_multicast_port_group_expired 1 1 643d 643d 0/2 auto-obsoleted due to no activity on 2024/09/03 00:58
upstream BUG: soft lockup in br_multicast_port_group_expired net 1 1 69d 69d 0/29 closed as invalid on 2026/03/06 16:20
android-54 BUG: soft lockup in br_multicast_port_group_expired (2) 1 2 317d 356d 0/2 auto-obsoleted due to no activity on 2025/07/26 14:48
android-5-10 BUG: soft lockup in br_multicast_port_group_expired 1 1 564d 564d 0/2 auto-obsoleted due to no activity on 2024/11/21 20:11
linux-5.15 INFO: rcu detected stall in br_multicast_port_group_expired 1 1 615d 615d 0/3 auto-obsoleted due to no activity on 2024/10/11 20:34

Sample crash report:
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff94785bf80 R15: 00007ffc0851ab48
 </TASK>
watchdog: BUG: soft lockup - CPU#0 stuck for 128s! [syz.2.94:828]
Modules linked in:
CPU: 0 PID: 828 Comm: syz.2.94 Not tainted 5.15.167-syzkaller-android13-5.15.167_r00 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:hlist_unhashed_lockless include/linux/list.h:839 [inline]
RIP: 0010:timer_pending include/linux/timer.h:172 [inline]
RIP: 0010:br_multicast_port_group_expired+0xe6/0x870 net/bridge/br_multicast.c:739
Code: 8b 1b 89 de 83 e6 01 31 ff e8 a6 2e fc fc f6 c3 01 75 07 e8 5c 2a fc fc eb 25 49 8d 5d 08 48 89 d8 48 c1 e8 03 42 80 3c 30 00 <74> 08 48 89 df e8 20 7c 3e fd 48 83 3b 00 74 1c e8 35 2a fc fc 4c
RSP: 0018:ffffc90000007cc0 EFLAGS: 00000246
RAX: 1ffff110246f460c RBX: ffff8881237a3060 RCX: ffff888110a1bb40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000007d50 R08: ffffffff84742d1a R09: ffffed1022a08808
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000100005e00
R13: ffff8881237a3058 R14: dffffc0000000000 R15: ffff888115044ddc
FS:  0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557648a4a8 CR3: 000000010fc6a000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 call_timer_fn+0x3b/0x2d0 kernel/time/timer.c:1457
 expire_timers kernel/time/timer.c:1502 [inline]
 __run_timers+0x72a/0xa10 kernel/time/timer.c:1773
 run_timer_softirq+0x69/0xf0 kernel/time/timer.c:1786
 handle_softirqs+0x25e/0x5c0 kernel/softirq.c:565
 __do_softirq kernel/softirq.c:603 [inline]
 invoke_softirq kernel/softirq.c:425 [inline]
 __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:652
 irq_exit_rcu+0x9/0x10 kernel/softirq.c:664
 sysvec_apic_timer_interrupt+0x9a/0xc0 arch/x86/kernel/apic/apic.c:1096
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:check_kcov_mode kernel/kcov.c:174 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:227 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x2e/0x80 kernel/kcov.c:300
Code: 4c 8b 45 08 65 48 8b 0d b0 11 92 7e 65 8b 05 b1 11 92 7e 25 00 01 ff 00 74 10 3d 00 01 00 00 75 57 83 b9 5c 0b 00 00 00 74 4e <8b> 81 38 0b 00 00 83 f8 03 75 43 48 8b 91 40 0b 00 00 44 8b 89 3c
RSP: 0018:ffffc90000ca75d0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88812bb2f1c0 RCX: ffff888110a1bb40
RDX: 0000555587000000 RSI: 000000012af3f007 RDI: 0000000000000000
RBP: ffffc90000ca75d0 R08: ffffffff81a6c837 R09: 0000000000000014
R10: ffffc90000ca7350 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff11025765e38 R14: ffff88812bb2f1c0 R15: 000000012af3f067
 pmd_none arch/x86/include/asm/pgtable.h:795 [inline]
 pmd_none_or_clear_bad include/linux/pgtable.h:875 [inline]
 free_pmd_range mm/memory.c:310 [inline]
 free_pud_range mm/memory.c:346 [inline]
 free_p4d_range mm/memory.c:380 [inline]
 free_pgd_range+0x537/0xdf0 mm/memory.c:460
 free_pgtables+0x19f/0x280 mm/memory.c:492
 exit_mmap+0x405/0x940 mm/mmap.c:3217
 __mmput+0x95/0x310 kernel/fork.c:1179
 mmput+0x5b/0x170 kernel/fork.c:1202
 exit_mm kernel/exit.c:554 [inline]
 do_exit+0xb9c/0x2ca0 kernel/exit.c:867
 do_group_exit+0x141/0x310 kernel/exit.c:1002
 get_signal+0x7a3/0x1630 kernel/signal.c:2904
 arch_do_signal_or_restart+0xbd/0x1680 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0xa0/0xe0 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x26/0x160 kernel/entry/common.c:307
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7ff9476a4719
Code: Unable to access opcode bytes at RIP 0x7ff9476a46ef.
RSP: 002b:00007ff94631d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007ff94785bf80 RCX: 00007ff9476a4719
RDX: 00000000200006c0 RSI: 0000000000005452 RDI: 0000000000000003
RBP: 00007ff94771739e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff94785bf80 R15: 00007ffc0851ab48
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 1309 Comm: syz.0.160 Not tainted 5.15.167-syzkaller-android13-5.15.167_r00 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:199
Code: 00 00 00 0f 0b 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb e8 13 00 00 00 48 8b 3d 14 3e b9 05 48 89 de e8 f4 8e 41 00 5b 5d c3 cc <55> 48 89 e5 48 8b 45 08 65 48 8b 0d f0 15 92 7e 65 8b 15 f1 15 92
RSP: 0000:ffffc900001cfb98 EFLAGS: 00000046
RAX: 000000000001b306 RBX: 7fffffffffffffff RCX: ffff888112bc13c0
RDX: 0000000000010100 RSI: 7fffffffffffffff RDI: 0000008594698b93
RBP: ffffc900001cfbe8 R08: ffffffff816185d1 R09: 0000000000000003
R10: fffff52000039f6c R11: dffffc0000000001 R12: 000000000001b306
R13: dffffc0000000000 R14: ffff8881f7129ab8 R15: 0000008594698b93
FS:  00007f9a335ee6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2a178c CR3: 00000001241d5000 CR4: 00000000003506a0
DR0: 0000000020000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 hrtimer_update_base kernel/time/hrtimer.c:631 [inline]
 hrtimer_interrupt+0x148/0xaa0 kernel/time/hrtimer.c:1795
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
 __sysvec_apic_timer_interrupt+0xfd/0x3c0 arch/x86/kernel/apic/apic.c:1102
 sysvec_apic_timer_interrupt+0x44/0xc0 arch/x86/kernel/apic/apic.c:1096
 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:update_stack_state+0x281/0x460 arch/x86/kernel/unwind_frame.c:224
Code: 00 fc ff df 41 80 3c 04 00 74 08 4c 89 f7 e8 56 a1 7d 00 49 83 3e 00 48 8b 45 a8 4c 8b ad 78 ff ff ff 74 22 44 3b 7d a4 75 1c <48> 3b 45 98 73 16 31 db 89 d8 48 81 c4 90 00 00 00 5b 41 5c 41 5d
RSP: 0000:ffffc900001cfe10 EFLAGS: 00000246
RAX: ffffc900001d06a0 RBX: ffffc900001cff88 RCX: ffffc900001d06b0
RDX: 1ffff92000039fee RSI: ffffc900001d06a0 RDI: ffffc900001cffb8
RBP: ffffc900001cfec8 R08: ffffc900001d0048 R09: 0000000000000007
R10: ffffc900001d0050 R11: dffffc0000000001 R12: 1ffff92000039ff4
R13: 0000000000000000 R14: ffffc900001cffa0 R15: 0000000000000002
 unwind_next_frame+0x3cb/0x700 arch/x86/kernel/unwind_frame.c:305
 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 kasan_save_stack+0x3b/0x60 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xd3/0xf0 mm/kasan/generic.c:348
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
 kvfree_call_rcu+0xb1/0x8b0 kernel/rcu/tree.c:3644
 neigh_destroy+0x411/0x540 net/core/neighbour.c:860
 neigh_release include/net/neighbour.h:427 [inline]
 neigh_cleanup_and_release+0x73/0x1b0 net/core/neighbour.c:103
 neigh_del net/core/neighbour.c:197 [inline]
 neigh_remove_one+0x3a6/0x430 net/core/neighbour.c:218
 neigh_forced_gc net/core/neighbour.c:251 [inline]
 neigh_alloc net/core/neighbour.c:429 [inline]
 ___neigh_create+0x474/0x1bd0 net/core/neighbour.c:591
 __neigh_create+0x32/0x40 net/core/neighbour.c:679
 ip6_finish_output2+0x9ee/0x16f0 net/ipv6/ip6_output.c:127
 __ip6_finish_output+0x60f/0x7c0 net/ipv6/ip6_output.c:201
 ip6_finish_output+0x31/0x210 net/ipv6/ip6_output.c:211
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0x1f7/0x4c0 net/ipv6/ip6_output.c:234
 dst_output include/net/dst.h:444 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ndisc_send_skb+0x73e/0xc90 net/ipv6/ndisc.c:511
 ndisc_send_rs+0x532/0x6a0 net/ipv6/ndisc.c:705
 addrconf_rs_timer+0x2d1/0x600 net/ipv6/addrconf.c:3979
 call_timer_fn+0x3b/0x2d0 kernel/time/timer.c:1457
 expire_timers kernel/time/timer.c:1502 [inline]
 __run_timers+0x72a/0xa10 kernel/time/timer.c:1773
 run_timer_softirq+0x69/0xf0 kernel/time/timer.c:1786
 handle_softirqs+0x25e/0x5c0 kernel/softirq.c:565
 __do_softirq kernel/softirq.c:603 [inline]
 invoke_softirq kernel/softirq.c:425 [inline]
 __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:652
 irq_exit_rcu+0x9/0x10 kernel/softirq.c:664
 sysvec_apic_timer_interrupt+0x9a/0xc0 arch/x86/kernel/apic/apic.c:1096
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:preempt_schedule_irq+0xc2/0x140 kernel/sched/core.c:6916
Code: 4c 89 e7 e8 90 7c cd fc f6 44 24 21 02 74 0b 0f 0b 48 f7 03 08 00 00 00 74 4d bf 01 00 00 00 e8 34 2f 67 fc fb bf 01 00 00 00 <e8> e9 e3 ff ff fa bf 01 00 00 00 e8 be 30 67 fc 65 48 8b 1d 76 40
RSP: 0000:ffffc90000cd7d40 EFLAGS: 00000246
RAX: 1ffff110225783ce RBX: 1ffff9200019afac RCX: ffffffff84e6ff00
RDX: 1ffff1102257827d RSI: 0000000000000000 RDI: 0000000000000001
RBP: ffffc90000cd7dd8 R08: ffffffff874ce040 R09: ffffffff874ce048
R10: ffffffff874ce058 R11: ffffffff874ce050 R12: ffffc90000cd7d60
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff9200019afa8
 irqentry_exit_cond_resched+0x2a/0x30 kernel/entry/common.c:398
 irqentry_exit+0x30/0x40 kernel/entry/common.c:432
 sysvec_apic_timer_interrupt+0x55/0xc0 arch/x86/kernel/apic/apic.c:1096
 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:exit_to_user_mode_loop+0x46/0xe0 kernel/entry/common.c:168
Code: 30 f2 56 00 e8 3b ae f7 00 fa e8 25 9f 81 03 65 48 8b 05 9d 3d a3 7e 48 8b 18 f7 c3 0e 30 02 00 0f 84 87 00 00 00 fb f6 c3 08 <74> 05 e8 73 f6 85 03 f7 c3 00 10 00 00 74 08 4c 89 f7 e8 f3 db 37
RSP: 0000:ffffc90000cd7ed0 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000008 RCX: ffff888112bc13c0
RDX: 1ffff1102257827d RSI: 0000000000000008 RDI: ffffc90000cd7f58
RBP: ffffc90000cd7ee0 R08: ffffffff874ce040 R09: ffffffff874ce048
R10: ffffffff874ce058 R11: ffffffff874ce050 R12: 0000000000000000
R13: 0000000000000000 R14: ffffc90000cd7f58 R15: ffff888112bc13c0
 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:214
 irqentry_exit_to_user_mode+0x9/0x10 kernel/entry/common.c:320
 irqentry_exit+0x12/0x40 kernel/entry/common.c:411
 sysvec_apic_timer_interrupt+0x55/0xc0 arch/x86/kernel/apic/apic.c:1096
 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0033:0x7f9a34975719
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9a335ee038 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007f9a34b2cf80 RCX: 00007f9a34975719
RDX: 00000000200006c0 RSI: 0000000000005452 RDI: 0000000000000003
RBP: 00007f9a349e839e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9a34b2cf80 R15: 00007ffec4b10cd8
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/07 03:33 android13-5.15-lts 5e4635681cf1 df3dc63b .config console log report info ci2-android-5-15-perf BUG: soft lockup in br_multicast_port_group_expired
2024/08/16 17:44 android13-5.15-lts da92e689a0c3 e1c76ab2 .config console log report info ci2-android-5-15-perf BUG: soft lockup in br_multicast_port_group_expired
* Struck through repros no longer work on HEAD.