syzbot


INFO: rcu detected stall in hsr_announce (3)

Status: upstream: reported on 2026/06/26 13:35
Reported-by: syzbot+e3a50322dcc0651cfbd4@syzkaller.appspotmail.com
First crash: 12d, last: 5d07h
Similar bugs (19)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: rcu detected stall in hsr_announce 1 3 572d 673d 0/3 auto-obsoleted due to no activity on 2025/03/22 17:50
upstream INFO: rcu detected stall in hsr_announce (3) net 1 1 2409d 2408d 0/29 closed as invalid on 2019/12/04 14:04
linux-6.1 INFO: rcu detected stall in hsr_announce (2) 1 2 221d 248d 0/3 auto-obsoleted due to no activity on 2026/03/09 02:56
upstream INFO: rcu detected stall in hsr_announce (5) net 1 4 1696d 1708d 0/29 closed as invalid on 2022/02/08 10:00
linux-6.6 BUG: soft lockup in hsr_announce origin:lts-only 1 C 2 3d09h 40d 0/2 upstream: reported C repro on 2026/05/28 20:15
upstream INFO: rcu detected stall in hsr_announce (6) kvm 1 2 1534d 1534d 0/29 auto-closed as invalid on 2022/06/25 07:59
linux-4.14 INFO: rcu detected stall in hsr_announce 1 C error 25 2196d 2394d 0/1 upstream: reported C repro on 2019/12/17 23:42
upstream INFO: rcu detected stall in hsr_announce (4) net 1 1 2035d 2035d 0/29 auto-closed as invalid on 2021/03/11 15:56
linux-5.15 INFO: rcu detected stall in hsr_announce (3) 1 5 129d 190d 0/3 auto-obsoleted due to no activity on 2026/06/09 03:32
upstream INFO: rcu detected stall in hsr_announce net 1 1 2488d 2488d 0/29 auto-closed as invalid on 2019/11/13 18:24
linux-6.6 INFO: rcu detected stall in hsr_announce 1 1 204d 204d 0/2 auto-obsoleted due to no activity on 2026/03/26 05:20
upstream INFO: rcu detected stall in hsr_announce (2) net 1 3 2413d 2413d 0/29 closed as invalid on 2019/11/29 14:24
upstream INFO: rcu detected stall in hsr_announce (7) net 1 30 512d 512d 0/29 closed as invalid on 2025/03/17 11:18
linux-5.15 INFO: rcu detected stall in hsr_announce (2) 1 1 321d 321d 0/3 auto-obsoleted due to no activity on 2025/11/28 17:51
linux-5.15 INFO: rcu detected stall in hsr_announce 1 6 645d 691d 0/3 auto-obsoleted due to no activity on 2025/01/08 22:52
linux-4.19 INFO: rcu detected stall in hsr_announce 1 1 2108d 2108d 0/1 auto-closed as invalid on 2021/01/27 07:34
linux-4.19 BUG: soft lockup in hsr_announce (2) 1 7 1359d 1813d 0/1 auto-obsoleted due to no activity on 2023/02/15 11:56
upstream BUG: soft lockup in hsr_announce (2) net 1 3 1014d 1023d 0/29 auto-obsoleted due to no activity on 2023/12/27 12:08
upstream BUG: soft lockup in hsr_announce (3) prio:normal net 1 syz 38 11d 441d 0/29 upstream: reported syz repro on 2025/04/23 07:51

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2668 jiffies s: 77241 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: 18572 Comm: syz.9.4806 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:perf_tp_event+0x183/0xc10 kernel/events/core.c:10041
Code: 07 e8 e1 db dc ff eb 1d 65 8b 1d 38 31 5d 7e 31 ff 89 de e8 2f df dc ff 85 db 0f 85 27 0a 00 00 e8 c2 db dc ff ba 00 01 00 00 <48> 8d 9c 24 80 00 00 00 48 89 df 31 f6 e8 1b 05 2e 00 48 8b 44 24
RSP: 0018:ffffc900001e0040 EFLAGS: 00000006
RAX: ffffffff81a5452f RBX: 0000000000010504 RCX: ffff88807a3ebc00
RDX: 0000000000000100 RSI: 0000000000010504 RDI: 0000000000000000
RBP: ffffc900001e02a8 R08: ffff8880b8f35600 R09: ffffe8ffffd3dd20
R10: dffffc0000000000 R11: fffffbfff1c4247e R12: dffffc0000000000
R13: 0000000000000034 R14: ffffe8ffffd3dd20 R15: ffffc900001e0200
FS:  00007f55e9fce6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000078160000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000000000008d24 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10032
 perf_trace_lock+0x301/0x390 include/trace/events/lock.h:50
 trace_lock_release include/trace/events/lock.h:69 [inline]
 lock_release+0x8ad/0x920 kernel/locking/lockdep.c:5673
 seqcount_lockdep_reader_access+0xe0/0x1d0 include/linux/seqlock.h:103
 timekeeping_get_delta kernel/time/timekeeping.c:254 [inline]
 timekeeping_get_ns kernel/time/timekeeping.c:388 [inline]
 ktime_get_update_offsets_now+0x95/0x3e0 kernel/time/timekeeping.c:2320
 hrtimer_update_base kernel/time/hrtimer.c:652 [inline]
 hrtimer_interrupt+0x11a/0x980 kernel/time/hrtimer.c:1859
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1118
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__raw_spin_lock_bh include/linux/spinlock_api_smp.h:127 [inline]
RIP: 0010:_raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178
Code: 89 f7 be 01 02 00 00 e8 a8 f2 14 f7 48 8d 7b 18 31 f6 31 d2 31 c9 41 b8 01 00 00 00 45 31 c9 41 56 e8 4e ad 29 f7 48 83 c4 08 <48> 89 df 5b 41 5e e9 df f1 2a f7 66 2e 0f 1f 84 00 00 00 00 00 0f
RSP: 0018:ffffc900001e0878 EFLAGS: 00000286
RAX: 5111169d78a71800 RBX: ffff88802f455c10 RCX: 5111169d78a71800
RDX: 0000000000000000 RSI: ffffffff8a8c2920 RDI: ffffffff8adf4160
RBP: 000000000000fc2d R08: dffffc0000000000 R09: 1ffffffff2162065
R10: dffffc0000000000 R11: fffffbfff2162066 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffffff8a0dea53 R15: ffff88802f455c00
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 hsr_register_frame_out+0x33/0x390 net/hsr/hsr_framereg.c:468
 hsr_forward_do net/hsr/hsr_forward.c:443 [inline]
 hsr_forward_skb+0xdcb/0x20c0 net/hsr/hsr_forward.c:626
 send_hsr_supervision_frame+0x5f7/0xb90 net/hsr/hsr_device.c:346
 hsr_announce+0x194/0x340 net/hsr/hsr_device.c:402
 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:2023
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x291/0x910 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:mas_next_entry+0x1a3/0xe90 lib/maple_tree.c:4833
Code: bf 04 00 00 00 44 89 ee e8 4a f5 64 f7 41 83 fd 03 0f 87 aa 00 00 00 49 8d 9d e0 be b1 8b 48 89 d8 48 c1 e8 03 42 0f b6 04 38 <84> c0 0f 85 d7 00 00 00 44 0f b6 3b 41 0f b6 fe 41 0f b6 df 89 de
RSP: 0018:ffffc900038d78d8 EFLAGS: 00000a02
RAX: 0000000000000004 RBX: ffffffff8bb1bee1 RCX: 0000000000000002
RDX: ffff88807a3ebc00 RSI: 0000000000000001 RDI: 0000000000000004
RBP: ffffc900038d7a00 R08: ffff88807a3ebc00 R09: 0000000000000002
R10: 0000000000000009 R11: 0000000000000002 R12: ffff888026352600
R13: 0000000000000001 R14: 0000000000000001 R15: dffffc0000000000
 mt_find+0x53f/0x830 lib/maple_tree.c:6550
 find_vma+0x12c/0x1b0 mm/mmap.c:1898
 lock_mm_and_find_vma+0x71/0x2f0 mm/memory.c:5385
 do_user_addr_fault+0x2e8/0xb20 arch/x86/mm/fault.c:1310
 handle_page_fault arch/x86/mm/fault.c:1429 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0010:copy_user_enhanced_fast_string+0xa/0x40 arch/x86/lib/copy_user_64.S:166
Code: ff c9 75 f2 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 8d 0c ca 89 ca eb 20 0f 01 cb 83 fa 40 72 38 89 d1 <f3> a4 31 c0 0f 01 ca c3 89 ca eb 0a 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900038d7d48 EFLAGS: 00050202
RAX: ffffffff84153e01 RBX: 0000000000000048 RCX: 0000000000000048
RDX: 0000000000000048 RSI: 0000000000000000 RDI: ffffc900038d7dc0
RBP: 0000000000000000 R08: ffffc900038d7e07 R09: 1ffff9200071afc0
R10: dffffc0000000000 R11: fffff5200071afc1 R12: 00007fffffffefb8
R13: 0000000000000048 R14: ffffc900038d7dc0 R15: 0000000000000000
 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
 raw_copy_from_user arch/x86/include/asm/uaccess_64.h:52 [inline]
 _copy_from_user+0xf4/0x170 lib/usercopy.c:23
 copy_from_user include/linux/uaccess.h:161 [inline]
 copy_from_bpfptr_offset include/linux/bpfptr.h:53 [inline]
 copy_from_bpfptr include/linux/bpfptr.h:59 [inline]
 __sys_bpf+0x2ea/0x780 kernel/bpf/syscall.c:5004
 __do_sys_bpf kernel/bpf/syscall.c:5135 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5133 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5133
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f55e919de59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f55e9fce028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f55e9425fa0 RCX: 00007f55e919de59
RDX: 0000000000000048 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f55e9233e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f55e9426038 R14: 00007f55e9425fa0 R15: 00007ffd4c549848
 </TASK>
net_ratelimit: 5163 callbacks suppressed
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:82:0c:e8:92:52:3d, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:82:0c:e8:92:52:3d, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:82:0c:e8:92:52:3d, vlan:0)
net_ratelimit: 8428 callbacks suppressed
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:82:0c:e8:92:52:3d, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/03 09:54 linux-6.1.y fdb6fcb41cc7 58bf2096 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in hsr_announce
2026/06/26 13:34 linux-6.1.y fdb6fcb41cc7 7ff32d8b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in hsr_announce
* Struck through repros no longer work on HEAD.