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INFO: rcu detected stall in mac80211_hwsim_beacon (4)

Status: upstream: reported on 2025/09/09 14:58
Reported-by: syzbot+16566e2176db580ec63f@syzkaller.appspotmail.com
First crash: 101d, last: 13h33m
▶ ▼ Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in mac80211_hwsim_beacon kernel 1 C error inconclusive 1904 1333d 1913d 0/29 closed as invalid on 2022/10/12 18:37
linux-6.1 INFO: rcu detected stall in mac80211_hwsim_beacon (3) 1 1 121d 121d 0/3 auto-obsoleted due to no activity on 2025/11/28 14:14
linux-5.15 INFO: rcu detected stall in mac80211_hwsim_beacon 1 1 791d 791d 0/3 auto-obsoleted due to no activity on 2024/01/28 07:17
linux-5.15 INFO: rcu detected stall in mac80211_hwsim_beacon (3) 1 3 445d 452d 0/3 auto-obsoleted due to no activity on 2025/01/08 17:17
linux-6.1 INFO: rcu detected stall in mac80211_hwsim_beacon (2) 1 1 330d 330d 0/3 auto-obsoleted due to no activity on 2025/05/03 16:43
linux-6.1 INFO: rcu detected stall in mac80211_hwsim_beacon 1 3 445d 470d 0/3 auto-obsoleted due to no activity on 2025/01/08 20:04
upstream BUG: soft lockup in mac80211_hwsim_beacon (2) wireless trace 1 C error inconclusive 153 13d 648d 0/29 upstream: reported C repro on 2024/03/11 14:28
linux-5.15 INFO: rcu detected stall in mac80211_hwsim_beacon (2) 1 1 668d 668d 0/3 auto-obsoleted due to no activity on 2024/05/30 17:39
upstream BUG: soft lockup in mac80211_hwsim_beacon wireless 1 syz error unreliable 180 1333d 1906d 0/29 auto-obsoleted due to no activity on 2023/01/21 14:41

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10500 ticks this GP) idle=7ab/1/0x4000000000000000 softirq=8093/8093 fqs=0 
	(t=10500 jiffies g=7861 q=1154)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g7861 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=4692
rcu: rcu_preempt kthread starved for 10500 jiffies! g7861 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
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:I stack:27328 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 4335 Comm: syz.0.13 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
 print_cpu_stall+0x318/0x5f0 kernel/rcu/tree_stall.h:631
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x6d8/0x1110 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:seqcount_lockdep_reader_access+0x17b/0x1c0 include/linux/seqlock.h:106
Code: 00 4d 85 e4 75 16 e8 54 cc 0f 00 eb 15 e8 4d cc 0f 00 e8 88 e7 39 08 4d 85 e4 74 ea e8 3e cc 0f 00 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3e 00 00 00 00 66 43 c7 44 3e 09 00 00 43 c6 44 3e 0b 00
RSP: 0018:ffffc90000007b20 EFLAGS: 00000246
RAX: ffffffff8167ffd2 RBX: 0000000000000000 RCX: ffff8880765fbb80
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000007bd8 R08: dffffc0000000000 R09: fffffbfff1ff541a
R10: fffffbfff1ff541a R11: 1ffffffff1ff5419 R12: 0000000000000200
R13: 0000005f6ba92b99 R14: 1ffff92000000f64 R15: dffffc0000000000
 ktime_get+0x31/0x270 kernel/time/timekeeping.c:829
 hrtimer_forward_now include/linux/hrtimer.h:508 [inline]
 mac80211_hwsim_beacon+0x13b/0x180 drivers/net/wireless/mac80211_hwsim.c:1874
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1749
 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:___might_sleep+0x1c/0x600 kernel/sched/core.c:9617
Code: ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec e0 00 00 00 89 54 24 2c <89> 74 24 14 48 89 7c 24 20 65 48 8b 04 25 28 00 00 00 48 89 84 24
RSP: 0018:ffffc900034af640 EFLAGS: 00000282
RAX: 1ffff11005970cd2 RBX: ffffffff964a3b80 RCX: 0000000000080000
RDX: 0000000000000000 RSI: 000000000000010b RDI: ffffffff8b08c520
RBP: ffffc900034af750 R08: dffffc0000000000 R09: fffffbfff1ad26b6
R10: fffffbfff1ad26b6 R11: 1ffffffff1ad26b5 R12: 0000000000070cd1
R13: dffffc0000000000 R14: ffff88802cb86690 R15: ffffffff8d40d0a8
 inet_twsk_purge+0x10a/0x810 net/ipv4/inet_timewait_sock.c:267
 ops_exit_list net/core/net_namespace.c:177 [inline]
 setup_net+0x822/0x9f0 net/core/net_namespace.c:365
 copy_net_ns+0x348/0x5b0 net/core/net_namespace.c:503
 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110
 copy_namespaces+0x37d/0x3e0 kernel/nsproxy.c:178
 copy_process+0x180f/0x3e00 kernel/fork.c:2293
 kernel_clone+0x219/0x930 kernel/fork.c:2679
 __do_sys_clone kernel/fork.c:2796 [inline]
 __se_sys_clone kernel/fork.c:2780 [inline]
 __x64_sys_clone+0x170/0x1c0 kernel/fork.c:2780
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f6529ab6749
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:00007f6527d1cfe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f6529d0cfa0 RCX: 00007f6529ab6749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040222000
RBP: 00007f6529b3af91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f6529d0d038 R14: 00007f6529d0cfa0 R15: 00007ffe04661018
 </TASK>
NMI backtrace for cpu 0
CPU: 0 PID: 4335 Comm: syz.0.13 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_dump_cpu_stacks+0x22f/0x380 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x31d/0x5f0 kernel/rcu/tree_stall.h:633
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x6d8/0x1110 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:seqcount_lockdep_reader_access+0x17b/0x1c0 include/linux/seqlock.h:106
Code: 00 4d 85 e4 75 16 e8 54 cc 0f 00 eb 15 e8 4d cc 0f 00 e8 88 e7 39 08 4d 85 e4 74 ea e8 3e cc 0f 00 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3e 00 00 00 00 66 43 c7 44 3e 09 00 00 43 c6 44 3e 0b 00
RSP: 0018:ffffc90000007b20 EFLAGS: 00000246
RAX: ffffffff8167ffd2 RBX: 0000000000000000 RCX: ffff8880765fbb80
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000007bd8 R08: dffffc0000000000 R09: fffffbfff1ff541a
R10: fffffbfff1ff541a R11: 1ffffffff1ff5419 R12: 0000000000000200
R13: 0000005f6ba92b99 R14: 1ffff92000000f64 R15: dffffc0000000000
 ktime_get+0x31/0x270 kernel/time/timekeeping.c:829
 hrtimer_forward_now include/linux/hrtimer.h:508 [inline]
 mac80211_hwsim_beacon+0x13b/0x180 drivers/net/wireless/mac80211_hwsim.c:1874
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1749
 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:___might_sleep+0x1c/0x600 kernel/sched/core.c:9617
Code: ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec e0 00 00 00 89 54 24 2c <89> 74 24 14 48 89 7c 24 20 65 48 8b 04 25 28 00 00 00 48 89 84 24
RSP: 0018:ffffc900034af640 EFLAGS: 00000282
RAX: 1ffff11005970cd2 RBX: ffffffff964a3b80 RCX: 0000000000080000
RDX: 0000000000000000 RSI: 000000000000010b RDI: ffffffff8b08c520
RBP: ffffc900034af750 R08: dffffc0000000000 R09: fffffbfff1ad26b6
R10: fffffbfff1ad26b6 R11: 1ffffffff1ad26b5 R12: 0000000000070cd1
R13: dffffc0000000000 R14: ffff88802cb86690 R15: ffffffff8d40d0a8
 inet_twsk_purge+0x10a/0x810 net/ipv4/inet_timewait_sock.c:267
 ops_exit_list net/core/net_namespace.c:177 [inline]
 setup_net+0x822/0x9f0 net/core/net_namespace.c:365
 copy_net_ns+0x348/0x5b0 net/core/net_namespace.c:503
 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110
 copy_namespaces+0x37d/0x3e0 kernel/nsproxy.c:178
 copy_process+0x180f/0x3e00 kernel/fork.c:2293
 kernel_clone+0x219/0x930 kernel/fork.c:2679
 __do_sys_clone kernel/fork.c:2796 [inline]
 __se_sys_clone kernel/fork.c:2780 [inline]
 __x64_sys_clone+0x170/0x1c0 kernel/fork.c:2780
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f6529ab6749
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:00007f6527d1cfe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f6529d0cfa0 RCX: 00007f6529ab6749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040222000
RBP: 00007f6529b3af91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f6529d0d038 R14: 00007f6529d0cfa0 R15: 00007ffe04661018
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/19 16:36 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in mac80211_hwsim_beacon
2025/11/18 00:10 linux-5.15.y cc5ec8769306 ef766cd7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in mac80211_hwsim_beacon
2025/09/09 14:57 linux-5.15.y 7a6c2d093c45 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in mac80211_hwsim_beacon
* Struck through repros no longer work on HEAD.