INFO: rcu detected stall in schedule_preempt_disabled

Status: upstream: reported on 2026/06/15 08:21
Reported-by: syzbot+8fd4ebb3dfb59e9dd666@syzkaller.appspotmail.com
First crash: 128d, last: 4d03h
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 INFO: rcu detected stall in schedule_preempt_disabled 1 1 268d 268d 0/2 auto-obsoleted due to no activity on 2026/05/07 02:22
linux-6.1 INFO: rcu detected stall in schedule_preempt_disabled 1 1 407d 407d 0/3 auto-obsoleted due to no activity on 2025/12/18 07:49

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-....: (1 GPs behind) idle=735/1/0x4000000000000002 softirq=24533/24534 fqs=5245 
	(detected by 1, t=10502 jiffies, g=31825, q=1285)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 11367 Comm: syz.4.1679 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:225 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x4/0x80 kernel/kcov.c:299
Code: 77 22 89 ff 89 f6 4a c7 44 02 08 05 00 00 00 4a 89 7c 02 10 4a 89 74 02 18 4a 89 44 02 20 48 ff c1 48 89 0a c3 90 48 8b 04 24 <65> 48 8b 0d 74 48 89 7e 65 8b 15 75 48 89 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc90000007358 EFLAGS: 00000046
RAX: ffffffff81980acb RBX: ffffc90000007500 RCX: ffff88805e0fbb80
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000007450 R08: ffffc900000074d7 R09: ffffc900000074a0
R10: dffffc0000000000 R11: fffff52000000e9b R12: dffffc0000000000
R13: ffffc90000007506 R14: 0000000000000000 R15: ffffc900000076c0
FS:  00007f350187b6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3ca03a964c CR3: 0000000069fae000 CR4: 00000000003506f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 perf_prepare_sample+0x97b/0x1cb0 kernel/events/core.c:7702
 __perf_event_output kernel/events/core.c:7812 [inline]
 perf_event_output_forward+0x185/0x2e0 kernel/events/core.c:7832
 __perf_event_overflow+0x35f/0x550 kernel/events/core.c:9525
 perf_swevent_overflow kernel/events/core.c:9601 [inline]
 perf_swevent_event+0x4b8/0x540 kernel/events/core.c:9639
 perf_tp_event+0x324/0xbe0 kernel/events/core.c:10057
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10031
 perf_trace_preemptirq_template+0x2aa/0x360 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 82 fc 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc90000007b00 EFLAGS: 00000206
RAX: c2ca7f9466d47800 RBX: 1ffff92000000f64 RCX: c2ca7f9466d47800
RDX: dffffc0000000000 RSI: ffffffff8a2b2b60 RDI: ffffffff8a7a4b40
RBP: ffffc90000007bd8 R08: ffffffff910150cf R09: 1ffffffff2202a19
R10: dffffc0000000000 R11: fffffbfff2202a1a R12: ffffffff8d123400
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 ieee80211_iterate_active_interfaces_atomic+0x132/0x140 net/mac80211/util.c:831
 mac80211_hwsim_beacon+0x9b/0x180 drivers/net/wireless/mac80211_hwsim.c:1865
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4ea/0xb60 kernel/time/hrtimer.c:1749
 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766
 handle_softirqs+0x336/0x830 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:finish_lock_switch+0x12f/0x290 kernel/sched/core.c:4804
Code: 83 c7 18 be ff ff ff ff e8 be bc 6d 08 85 c0 74 46 4d 85 ff 75 62 0f 1f 44 00 00 48 89 df e8 58 2d 77 08 e8 a3 f2 2a 00 fb 5b <41> 5c 41 5d 41 5e 41 5f 5d c3 48 89 df e8 2f 0e fe ff 43 80 3c 2c
RSP: 0018:ffffc9000304eff8 EFLAGS: 00000286
RAX: c2ca7f9466d47800 RBX: ffff888075d1bb80 RCX: c2ca7f9466d47800
RDX: dffffc0000000000 RSI: ffffffff8a2b2b60 RDI: ffffffff8a7a4b40
RBP: 1ffff110171c7613 R08: ffffffff910150cf R09: 1ffffffff2202a19
R10: dffffc0000000000 R11: fffffbfff2202a1a R12: 1ffff110171c75c1
R13: dffffc0000000000 R14: ffff8880b8e3ae08 R15: 0000000000000000
 finish_task_switch+0x12f/0x650 kernel/sched/core.c:4921
 context_switch kernel/sched/core.c:5052 [inline]
 __schedule+0x11cb/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xdf5/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 rtnl_lock net/core/rtnetlink.c:72 [inline]
 rtnetlink_rcv_msg+0x79f/0xf10 net/core/rtnetlink.c:5695
 netlink_rcv_skb+0x1e9/0x430 net/netlink/af_netlink.c:2519
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x78f/0x940 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 ____sys_sendmsg+0x5be/0x8f0 net/socket.c:2446
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2500
 __sys_sendmsg net/socket.c:2529 [inline]
 __do_sys_sendmsg net/socket.c:2538 [inline]
 __se_sys_sendmsg+0x1b7/0x2a0 net/socket.c:2536
 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: 0033:0x7f3503665559
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:00007f350187b028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f35038ed180 RCX: 00007f3503665559
RDX: 000000000000c800 RSI: 00002000000000c0 RDI: 0000000000000000
RBP: 00007f35036fcab8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f35038ed218 R14: 00007f35038ed180 R15: 00007ffde6655f88
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/18 03:34 linux-5.15.y 792fbe1537d8 432c0077 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in schedule_preempt_disabled
2026/09/05 13:52 linux-5.15.y 0996e0926f6b 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in schedule_preempt_disabled
2026/06/15 08:21 linux-5.15.y dc027a595035 1d2f3589 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in schedule_preempt_disabled
* Struck through repros no longer work on HEAD.