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: 330d, last: 91d
▶ ▼ Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: rcu detected stall in mac80211_hwsim_beacon (4) origin:lts-only 1 syz, C error 13 13d 112d 0/3 upstream: reported C repro on 2026/04/15 21:01
upstream INFO: rcu detected stall in mac80211_hwsim_beacon kernel 1 syz, C error inconclusive 1904 1563d 2142d 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 350d 350d 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 1021d 1021d 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 674d 682d 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 559d 559d 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 674d 699d 0/3 auto-obsoleted due to no activity on 2025/01/08 20:04
linux-6.6 INFO: rcu detected stall in mac80211_hwsim_beacon origin:lts-only 1 syz, C 2 20d 57d 0/2 upstream: reported C repro on 2026/06/10 10:49
upstream BUG: soft lockup in mac80211_hwsim_beacon (2) wireless prio:high 1 syz, C error inconclusive 171 116d 877d 0/29 auto-obsoleted due to no activity on 2026/06/21 00:56
linux-5.15 INFO: rcu detected stall in mac80211_hwsim_beacon (2) 1 1 897d 897d 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 1563d 2135d 0/29 auto-obsoleted due to no activity on 2023/01/21 14:41
upstream BUG: soft lockup in mac80211_hwsim_beacon (3) virt prio:normal 1 2 10d 7d05h 0/29 moderation: reported on 2026/07/30 07:17

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (3981 ticks this GP) idle=567/1/0x4000000000000000 softirq=24087/24089 fqs=5234 
	(t=10500 jiffies g=32665 q=2828)
NMI backtrace for cpu 1
CPU: 1 PID: 8654 Comm: syz.4.1183 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 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+0x6ea/0x1120 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:2021
 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+0x4b4/0xb70 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:arch_stack_walk+0x100/0x140 arch/x86/kernel/stacktrace.c:27
Code: 76 62 08 00 83 bd 78 ff ff ff 00 74 32 4c 8d bd 78 ff ff ff 4c 89 ff e8 8e 42 08 00 48 85 c0 74 1e 48 89 df 48 89 c6 41 ff d6 <84> c0 74 11 4c 89 ff e8 94 43 08 00 83 bd 78 ff ff ff 00 75 d5 65
RSP: 0018:ffffc90000dd03a8 EFLAGS: 00000292
RAX: 0000000000000001 RBX: ffffc90000dd0460 RCX: 0000000000000101
RDX: dffffc0000000000 RSI: ffffffff8187e7cf RDI: ffffc90000dd0460
RBP: ffffc90000dd0430 R08: ffffc90000dd0470 R09: 0000000000000022
R10: dffffc0000000000 R11: fffff520001ba081 R12: ffff888023815940
R13: ffff888144bf1140 R14: ffffffff8167ad70 R15: ffffc90000dd03a8
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 kmem_cache_alloc_node+0x12d/0x2d0 mm/slub.c:3261
 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415
 __netdev_alloc_skb+0x110/0x4c0 net/core/skbuff.c:494
 netdev_alloc_skb include/linux/skbuff.h:3024 [inline]
 dev_alloc_skb include/linux/skbuff.h:3037 [inline]
 __ieee80211_beacon_get+0xaa1/0x2000 net/mac80211/tx.c:5088
 ieee80211_beacon_get_tim+0x48/0x840 net/mac80211/tx.c:5202
 ieee80211_beacon_get include/net/mac80211.h:4983 [inline]
 mac80211_hwsim_beacon_tx+0xf4/0x920 drivers/net/wireless/mac80211_hwsim.c:1812
 __iterate_interfaces+0x243/0x500 net/mac80211/util.c:793
 ieee80211_iterate_active_interfaces_atomic+0xb3/0x140 net/mac80211/util.c:829
 mac80211_hwsim_beacon+0x9b/0x180 drivers/net/wireless/mac80211_hwsim.c:1865
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4f2/0xb70 kernel/time/hrtimer.c:1749
 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766
 handle_softirqs+0x339/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 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:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:202
Code: 66 2e 0f 1f 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d d0 bd 10 0c 48 89 de 5b e9 27 55 44 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d 24 3b 89 7e 65 8b 15 25 3b 89 7e 81 e2 00
RSP: 0018:ffffc90003caed08 EFLAGS: 00000246
RAX: 1ffff1102800a84d RBX: 0000000000000001 RCX: 0000000000080000
RDX: ffffc90010f62000 RSI: 000000000000170f RDI: 0000000000001710
RBP: 0000000000000000 R08: ffff888140054207 R09: 1ffff1102800a840
R10: dffffc0000000000 R11: ffffed102800a841 R12: dffffc0000000000
R13: ffffffffffffffff R14: 0000000000000000 R15: 0000000000000439
 page_counter_uncharge+0xf7/0x110 mm/page_counter.c:159
 obj_cgroup_uncharge_pages mm/memcontrol.c:2995 [inline]
 __memcg_kmem_uncharge_page+0x12e/0x140 mm/memcontrol.c:3083
 memcg_kmem_uncharge_page include/linux/memcontrol.h:1703 [inline]
 free_thread_stack+0x275/0x430 kernel/fork.c:283
 release_task_stack kernel/fork.c:433 [inline]
 put_task_stack+0x97/0x140 kernel/fork.c:444
 finish_task_switch+0x26f/0x640 kernel/sched/core.c:4961
 context_switch kernel/sched/core.c:5052 [inline]
 __schedule+0x11f7/0x43c0 kernel/sched/core.c:6395
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
 irqentry_exit+0x63/0x70 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__nr_to_section include/linux/mmzone.h:1383 [inline]
RIP: 0010:__pfn_to_section include/linux/mmzone.h:1468 [inline]
RIP: 0010:lookup_page_ext+0x59/0x120 mm/page_ext.c:209
Code: ff 03 00 00 00 48 89 de e8 b4 31 b3 ff 48 89 d8 48 c1 e8 22 0f 85 c2 00 00 00 48 c7 c0 80 4b 33 96 48 c1 e8 03 42 80 3c 38 00 <74> 0c 48 c7 c7 80 4b 33 96 e8 79 4c f8 ff 48 8b 05 92 44 6d 14 48
RSP: 0018:ffffc90003caf188 EFLAGS: 00000246
RAX: 1ffffffff2c66970 RBX: 000000000005fc71 RCX: ffff888023815940
RDX: 0000000000000002 RSI: 000000000005fc71 RDI: 00000003ffffffff
RBP: 0000000000000000 R08: ffffea00017f1c77 R09: ffffed100bf8e200
R10: dffffc0000000000 R11: fffff940002fe38f R12: 0000000000102dc2
R13: 0000000000000000 R14: ffffea00017f1c40 R15: dffffc0000000000
 __set_page_owner+0x23/0x2d0 mm/page_owner.c:175
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 vm_area_alloc_pages mm/vmalloc.c:2876 [inline]
 __vmalloc_area_node mm/vmalloc.c:2932 [inline]
 __vmalloc_node_range+0x4b2/0x8b0 mm/vmalloc.c:3037
 __vmalloc_node mm/vmalloc.c:3087 [inline]
 vzalloc+0x75/0x80 mm/vmalloc.c:3157
 bpf_check+0x1bf/0xf270 kernel/bpf/verifier.c:14053
 bpf_prog_load+0xfec/0x1510 kernel/bpf/syscall.c:2354
 __sys_bpf+0x532/0x6f0 kernel/bpf/syscall.c:4657
 __do_sys_bpf kernel/bpf/syscall.c:4761 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4759 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4759
 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: 0033:0x7f38c2c6ddd9
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:00007f38c0ea6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f38c2ee7090 RCX: 00007f38c2c6ddd9
RDX: 0000000000000048 RSI: 0000200000000080 RDI: 0000000000000005
RBP: 00007f38c2d03d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f38c2ee7128 R14: 00007f38c2ee7090 R15: 00007ffc37e3c128
 </TASK>

Crashes (8):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/06 16:41 linux-5.15.y ef251c45f1cd 1dddfd3d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in mac80211_hwsim_beacon
2026/05/02 11:24 linux-5.15.y ef251c45f1cd a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in mac80211_hwsim_beacon
2026/03/01 09:05 linux-5.15.y 3330a8d33e08 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in mac80211_hwsim_beacon
2026/02/14 01:57 linux-5.15.y e45d5d41c134 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in mac80211_hwsim_beacon
2026/01/19 05:09 linux-5.15.y 68efe5a6c16a 20d37d28 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in mac80211_hwsim_beacon
2025/12/19 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.