syzbot

 sign-in | mailing list | source | docs
🐞 Open [925]
🐞 Fixed [145]
🐞 Invalid [1148]
⬇ Missing Backports [73]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
💬 Send us feedback

INFO: rcu detected stall in irqentry_exit

Status: auto-obsoleted due to no activity on 2024/11/25 13:22
Reported-by: syzbot+73aa08cc18a21c0facde@syzkaller.appspotmail.com
First crash: 679d, last: 679d
▶ ▼ Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 INFO: rcu detected stall in irqentry_exit origin:lts-only 1 C inconclusive 21 13d 306d 0/2 upstream: reported C repro on 2025/08/25 11:36
linux-5.15 INFO: rcu detected stall in irqentry_exit (2) 1 10 23d 284d 0/3 upstream: reported on 2025/09/16 14:07
linux-6.1 INFO: rcu detected stall in irqentry_exit (2) origin:lts-only 1 syz error 2 30d 229d 0/3 upstream: reported syz repro on 2025/11/10 20:44
linux-5.15 INFO: rcu detected stall in irqentry_exit 1 1 747d 747d 0/3 auto-obsoleted due to no activity on 2024/09/18 22:14
upstream INFO: rcu detected stall in irqentry_exit (2) kernel 1 C 1 262d 262d 0/29 closed as invalid on 2026/01/13 17:54
upstream INFO: rcu detected stall in irqentry_exit kernel 1 syz inconclusive inconclusive 2 555d 551d 0/29 auto-obsoleted due to no activity on 2025/03/29 05:27

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2632 jiffies s: 1425 root: 0x2/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3737 Comm: syz.3.8 Not tainted 6.1.105-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:lockdep_hardirqs_off+0x45/0x100 kernel/locking/lockdep.c:4407
Code: 00 0f 84 8d 00 00 00 49 89 fe 65 8b 05 6c 22 5d 75 a9 00 00 f0 00 74 65 83 3d 76 d4 4d 07 00 75 15 48 c7 04 24 00 00 00 00 9c <8f> 04 24 f7 04 24 00 02 00 00 75 76 65 8b 05 a8 28 5d 75 85 c0 74
RSP: 0018:ffffc900001e02c0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffffff8aafaa4c RCX: ffff888028263b80
RDX: 0000000000000100 RSI: ffffffff8b0c0280 RDI: ffffffff8b5d5ec0
RBP: ffffc900001e0398 R08: ffffffff889b4cdc R09: fffffbfff1d339ae
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000246
R13: 1ffff9200003c060 R14: ffffffff8aafaa4c R15: dffffc0000000000
FS:  00007fd03e1876c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f110ff8 CR3: 0000000058114000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 trace_hardirqs_off+0xe/0x40 kernel/trace/trace_preemptirq.c:76
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline]
 _raw_spin_lock_irqsave+0xac/0x120 kernel/locking/spinlock.c:162
 rps_lock_irqsave net/core/dev.c:224 [inline]
 enqueue_to_backlog+0x76/0xc00 net/core/dev.c:4710
 netif_rx_internal+0x164/0x600 net/core/dev.c:4993
 __netif_rx+0x74/0xb0 net/core/dev.c:5013
 veth_forward_skb drivers/net/veth.c:290 [inline]
 veth_xmit+0x679/0xb10 drivers/net/veth.c:343
 __netdev_start_xmit include/linux/netdevice.h:4853 [inline]
 netdev_start_xmit include/linux/netdevice.h:4867 [inline]
 xmit_one net/core/dev.c:3627 [inline]
 dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3643
 __dev_queue_xmit+0x1bb1/0x3cf0 net/core/dev.c:4293
 dev_queue_xmit include/linux/netdevice.h:3021 [inline]
 hsr_xmit net/hsr/hsr_forward.c:380 [inline]
 hsr_forward_do net/hsr/hsr_forward.c:471 [inline]
 hsr_forward_skb+0x17f3/0x2390 net/hsr/hsr_forward.c:619
 send_hsr_supervision_frame+0x540/0xad0 net/hsr/hsr_device.c:323
 hsr_announce+0x1a4/0x340 net/hsr/hsr_device.c:379
 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1504
 expire_timers kernel/time/timer.c:1549 [inline]
 __run_timers+0x67c/0x890 kernel/time/timer.c:1820
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
 handle_softirqs+0x2ee/0xa40 kernel/softirq.c:571
 __do_softirq kernel/softirq.c:605 [inline]
 invoke_softirq kernel/softirq.c:445 [inline]
 __irq_exit_rcu+0x157/0x240 kernel/softirq.c:654
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:666
 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:preempt_schedule_irq+0xf2/0x1c0 kernel/sched/core.c:6870
Code: 89 f5 49 c1 ed 03 eb 0d 48 f7 03 08 00 00 00 0f 84 97 00 00 00 bf 01 00 00 00 e8 99 74 b0 f6 e8 54 72 e3 f6 fb bf 01 00 00 00 <e8> 79 b4 ff ff 43 80 7c 3d 00 00 74 08 4c 89 f7 e8 f9 2a 34 f7 48
RSP: 0018:ffffc9000497f880 EFLAGS: 00000282
RAX: 0142748e4ddea800 RBX: 1ffff9200092ff18 RCX: ffffffff91f32103
RDX: dffffc0000000000 RSI: ffffffff8b0c0260 RDI: 0000000000000001
RBP: ffffc9000497f930 R08: ffffffff9013d040 R09: ffffffff9013d048
R10: ffffffff9013d058 R11: ffffffff9013d050 R12: 1ffff9200092ff10
R13: 1ffff9200092ff14 R14: ffffc9000497f8a0 R15: dffffc0000000000
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:__stack_depot_save+0x14a/0x470 lib/stackdepot.c:445
Code: 41 29 cd 44 31 e8 44 89 e9 c1 c1 04 29 c8 31 c5 c1 c0 0e 29 c5 41 31 ed c1 c5 18 41 29 ed eb 03 44 89 e7 48 8b 05 6e 25 c6 0d <8b> 1d 64 25 c6 0d 44 21 eb 48 89 44 24 10 4c 8b 34 d8 4c 89 c5 41
RSP: 0018:ffffc9000497f9f8 EFLAGS: 00000216
RAX: ffff88823b400000 RBX: 00000000b7a6bef4 RCX: 000000009d14fd92
RDX: ffffc9000497fab4 RSI: 0000000000000001 RDI: 0000000000000800
RBP: 000000005b5b1e7c R08: 000000000000000b R09: 0000000000000001
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000800
R13: 0000000017741506 R14: 0000000000000000 R15: ffffc9000497fa60
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x60/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1724 [inline]
 slab_free_freelist_hook mm/slub.c:1750 [inline]
 slab_free mm/slub.c:3661 [inline]
 kmem_cache_free+0x292/0x510 mm/slub.c:3683
 file_free fs/file_table.c:56 [inline]
 __fput+0x665/0x8d0 fs/file_table.c:333
 task_work_run+0x246/0x300 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd03d379e79
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:00007fd03e187038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: fffffffffffffff7 RBX: 00007fd03d515f80 RCX: 00007fd03d379e79
RDX: 0000000000000000 RSI: 0000000020000240 RDI: ffffffffffffffff
RBP: 00007fd03d3e7916 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd03d515f80 R15: 00007ffc1f4730e8
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/17 13:21 linux-6.1.y 117ac406ba90 dbc93b08 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in irqentry_exit
* Struck through repros no longer work on HEAD.