syzbot

 sign-in | mailing list | source | docs | 🏰
🐞 Open [1321]
≡ Subsystems
🐞 Fixed [7190]
🐞 Invalid [18989]
⬇ Missing Backports [221]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
Total Repo Heatmap Subsystems Heatmap
✨ AI
💬 Send us feedback

INFO: rcu detected stall in packet_rcv (2)

Status: auto-obsoleted due to no activity on 2024/03/25 03:49
Subsystems: net
[Documentation on labels]
First crash: 913d, last: 913d
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in packet_rcv net 1 1 1710d 1710d 0/29 auto-closed as invalid on 2021/12/19 00:49
upstream INFO: rcu detected stall in packet_rcv (3) net bpf 1 4 679d 705d 0/29 auto-obsoleted due to no activity on 2024/11/13 10:03
android-6-1 BUG: soft lockup in packet_rcv 1 1 46d 46d 0/2 premoderation: reported on 2026/05/10 15:44
upstream BUG: soft lockup in packet_rcv perf trace 1 2 179d 231d 0/29 closed as invalid on 2026/02/11 22:39

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=f39c/1/0x4000000000000000 softirq=64492/64492 fqs=543
rcu: 	(detected by 1, t=10502 jiffies, g=111105, q=179 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5052 Comm: syz-fuzzer Not tainted 6.7.0-rc7-syzkaller-00003-gfbafc3e621c3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x24/0x60 kernel/kcov.c:207
Code: 00 00 00 00 66 90 f3 0f 1e fa 65 48 8b 14 25 00 bd 03 00 65 8b 05 74 58 7d 7e a9 00 01 ff 00 48 8b 34 24 74 0f f6 c4 01 74 35 <8b> 82 fc 15 00 00 85 c0 74 2b 8b 82 d8 15 00 00 83 f8 02 75 20 48
RSP: 0018:ffffc90000007470 EFLAGS: 00000002
RAX: 0000000080010101 RBX: ffff8880b982ba40 RCX: ffffffff817519bb
RDX: ffff88801f5900c0 RSI: ffffffff81751da8 RDI: 0000000000000001
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000003 R12: ffff8880b982b940
R13: 0000000000000001 R14: ffff8880784c0340 R15: ffffffff88a26490
FS:  0000000001f3c2b0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020266000 CR3: 000000001ca6b000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 trace_hrtimer_expire_entry include/trace/events/timer.h:239 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x9d8/0xc20 kernel/time/hrtimer.c:1752
 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline]
 __sysvec_apic_timer_interrupt+0x105/0x400 arch/x86/kernel/apic/apic.c:1082
 sysvec_apic_timer_interrupt+0x43/0xb0 arch/x86/kernel/apic/apic.c:1076
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:__sanitizer_cov_trace_pc+0x59/0x60 kernel/kcov.c:225
Code: 82 d8 15 00 00 83 f8 02 75 20 48 8b 8a e0 15 00 00 8b 92 dc 15 00 00 48 8b 01 48 83 c0 01 48 39 d0 73 07 48 89 01 48 89 34 c1 <c3> 66 0f 1f 44 00 00 f3 0f 1e fa 41 57 41 56 49 89 d6 41 55 41 54
RSP: 0018:ffffc900000076f8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88802a084dc0 RCX: ffffffff88697b9c
RDX: ffff88801f5900c0 RSI: ffffffff89524a0d RDI: 0000000000000005
RBP: 0000000000000002 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000002 R12: ffff88807adaa000
R13: ffff88802a084e98 R14: 0000000000000000 R15: ffff88802a084e30
 packet_rcv+0x15d/0x1610 net/packet/af_packet.c:2231
 deliver_skb net/core/dev.c:2205 [inline]
 deliver_ptype_list_skb net/core/dev.c:2220 [inline]
 __netif_receive_skb_core.constprop.0+0xda9/0x3f50 net/core/dev.c:5483
 __netif_receive_skb_list_core+0x343/0x8a0 net/core/dev.c:5608
 __netif_receive_skb_list net/core/dev.c:5675 [inline]
 netif_receive_skb_list_internal+0x769/0xe00 net/core/dev.c:5766
 gro_normal_list include/net/gro.h:439 [inline]
 gro_normal_list include/net/gro.h:435 [inline]
 napi_complete_done+0x23f/0x990 net/core/dev.c:6106
 virtqueue_napi_complete drivers/net/virtio_net.c:440 [inline]
 virtnet_poll+0xf4a/0x15d0 drivers/net/virtio_net.c:2158
 __napi_poll.constprop.0+0xb4/0x540 net/core/dev.c:6536
 napi_poll net/core/dev.c:6605 [inline]
 net_rx_action+0x956/0xe90 net/core/dev.c:6738
 __do_softirq+0x21a/0x8de kernel/softirq.c:553
 invoke_softirq kernel/softirq.c:427 [inline]
 __irq_exit_rcu kernel/softirq.c:632 [inline]
 irq_exit_rcu+0xb7/0x120 kernel/softirq.c:644
 common_interrupt+0xb0/0xd0 arch/x86/kernel/irq.c:247
 </IRQ>
 <TASK>
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:640
RIP: 0010:write_comp_data+0x7e/0x80 kernel/kcov.c:262
Code: 00 00 4a 8d 34 dd 28 00 00 00 48 39 f2 72 1b 48 83 c7 01 48 89 38 4c 89 44 30 e0 4c 89 4c 30 e8 4c 89 54 30 f0 4a 89 4c d8 20 <c3> 90 f3 0f 1e fa 48 8b 0c 24 40 0f b6 d6 40 0f b6 f7 31 ff e9 69
RSP: 0018:ffffc9000332f418 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffffffff8139fcf5
RDX: ffff88801f5900c0 RSI: 0000000000000004 RDI: 0000000000000001
RBP: ffffffff8ac9d140 R08: 0000000000000001 R09: 0000000000000004
R10: 0000000000000005 R11: 0000000000000001 R12: 0000000000000005
R13: 0000000000000001 R14: 0000000000000008 R15: ffffc9000332f505
 __sanitizer_cov_trace_switch+0x54/0x90 kernel/kcov.c:341
 unwind_next_frame+0x6b5/0x2390 arch/x86/kernel/unwind_orc.c:515
 arch_stack_walk+0xfa/0x170 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x96/0xd0 kernel/stacktrace.c:122
 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 __kasan_slab_alloc+0x81/0x90 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook mm/slab.h:763 [inline]
 slab_alloc_node mm/slab.c:3237 [inline]
 kmem_cache_alloc_node+0x173/0x4a0 mm/slab.c:3509
 kmalloc_reserve+0x166/0x260 net/core/skbuff.c:560
 __alloc_skb+0x12b/0x330 net/core/skbuff.c:651
 alloc_skb_fclone include/linux/skbuff.h:1336 [inline]
 tcp_stream_alloc_skb+0x34/0x560 net/ipv4/tcp.c:871
 tcp_sendmsg_locked+0xeb2/0x3460 net/ipv4/tcp.c:1153
 tcp_sendmsg+0x2e/0x40 net/ipv4/tcp.c:1340
 inet_sendmsg+0x9d/0xe0 net/ipv4/af_inet.c:847
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0xd5/0x180 net/socket.c:745
 sock_write_iter+0x29b/0x3d0 net/socket.c:1158
 call_write_iter include/linux/fs.h:2020 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x64f/0xdf0 fs/read_write.c:584
 ksys_write+0x1f0/0x250 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x40/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x40720e
Code: 48 83 ec 38 e8 13 00 00 00 48 83 c4 38 5d c3 cc cc cc cc cc cc cc cc cc cc cc cc cc 49 89 f2 48 89 fa 48 89 ce 48 89 df 0f 05 <48> 3d 01 f0 ff ff 76 15 48 f7 d8 48 89 c1 48 c7 c0 ff ff ff ff 48
RSP: 002b:000000c00152b100 EFLAGS: 00000212 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000040720e
RDX: 00000000000000f0 RSI: 000000c0003d4200 RDI: 0000000000000003
RBP: 000000c00152b140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 000000c00152b280
R13: 0000000000000001 R14: 000000c00ebc4000 R15: 000000000000000e
 </TASK>
rcu: rcu_preempt kthread starved for 7785 jiffies! g111105 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:28240 pid:16    tgid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5376 [inline]
 __schedule+0xedb/0x5af0 kernel/sched/core.c:6688
 __schedule_loop kernel/sched/core.c:6763 [inline]
 schedule+0xe9/0x270 kernel/sched/core.c:6778
 schedule_timeout+0x137/0x290 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x1ec/0xb10 kernel/rcu/tree.c:1631
 rcu_gp_kthread+0x24b/0x380 kernel/rcu/tree.c:1830
 kthread+0x2c6/0x3a0 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 10149 Comm: kworker/u4:20 Not tainted 6.7.0-rc7-syzkaller-00003-gfbafc3e621c3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:write_comp_data+0x7e/0x80 kernel/kcov.c:262
Code: 00 00 4a 8d 34 dd 28 00 00 00 48 39 f2 72 1b 48 83 c7 01 48 89 38 4c 89 44 30 e0 4c 89 4c 30 e8 4c 89 54 30 f0 4a 89 4c d8 20 <c3> 90 f3 0f 1e fa 48 8b 0c 24 40 0f b6 d6 40 0f b6 f7 31 ff e9 69
RSP: 0018:ffffc90004e77928 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b98414c0 RCX: ffffffff817aada8
RDX: ffff888031596100 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000006 R12: ffffed1017308299
R13: 0000000000000001 R14: ffff8880b98414c8 R15: ffff8880b993d900
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556b74060310 CR3: 000000000cd77000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 csd_lock_wait kernel/smp.c:311 [inline]
 smp_call_function_many_cond+0x508/0x1550 kernel/smp.c:855
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1023
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:2016 [inline]
 text_poke_bp_batch+0x22b/0x750 arch/x86/kernel/alternative.c:2226
 text_poke_flush arch/x86/kernel/alternative.c:2417 [inline]
 text_poke_flush arch/x86/kernel/alternative.c:2414 [inline]
 text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2424
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 jump_label_update+0x1d7/0x400 kernel/jump_label.c:829
 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:205
 static_key_enable+0x1a/0x20 kernel/jump_label.c:218
 toggle_allocation_gate mm/kfence/core.c:830 [inline]
 toggle_allocation_gate+0xf4/0x250 mm/kfence/core.c:822
 process_one_work+0x886/0x15d0 kernel/workqueue.c:2627
 process_scheduled_works kernel/workqueue.c:2700 [inline]
 worker_thread+0x8b9/0x1290 kernel/workqueue.c:2781
 kthread+0x2c6/0x3a0 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/12/26 03:49 upstream fbafc3e621c3 fb427a07 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in packet_rcv
* Struck through repros no longer work on HEAD.