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INFO: rcu detected stall in irqentry_exit

Status: upstream: reported C repro on 2025/08/25 11:36
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+b88c7fb221e9dae9caf0@syzkaller.appspotmail.com
First crash: 300d, last: 7d06h
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2025/11/20 linux-6.6.y (ToT) 0a805b6ea8cd C [report] INFO: rcu detected stall in smp_call_function
2025/11/20 upstream (ToT) fd95357fd8c6 C Didn't crash
▶ ▼ Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: rcu detected stall in irqentry_exit 1 1 673d 673d 0/3 auto-obsoleted due to no activity on 2024/11/25 13:22
linux-5.15 INFO: rcu detected stall in irqentry_exit (2) 1 10 17d 278d 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 24d 223d 0/3 upstream: reported syz repro on 2025/11/10 20:44
linux-5.15 INFO: rcu detected stall in irqentry_exit 1 1 741d 741d 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 256d 256d 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 549d 545d 0/29 auto-obsoleted due to no activity on 2025/03/29 05:27
▶ ▼ Fix bisection attempts (1)
Created Duration User Patch Repo Result
2025/12/12 10:04 2h45m fix candidate upstream OK (0) job log

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (1 GPs behind) idle=bb04/1/0x4000000000000000 softirq=12318/12319 fqs=5054
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:  1320323          0            0
rcu: 	cputime:    21096      31383           29   ==> 52490(ms)
rcu: 	(t=10501 jiffies g=9445 q=17646 ncpus=2)
CPU: 1 PID: 5975 Comm: syz.0.38 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:kcov_remote_start+0x2b/0x7e0 kernel/kcov.c:933
Code: 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 18 65 4c 8b 35 a6 82 7c 7e 48 b8 00 00 00 00 ff ff ff 00 48 85 c7 74 11 0f 0b <48> 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f 5d c3 48 89 f8 48 c1 e8 39
RSP: 0018:ffffc900001f0990 EFLAGS: 00000206
RAX: f3889d328931f400 RBX: 0000000000000246 RCX: f3889d328931f400
RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: ffffffff8b1c9c20
RBP: ffffc900001f0c30 R08: ffffffff8e8b666f R09: 1ffffffff1d16ccd
R10: dffffc0000000000 R11: fffffbfff1d16cce R12: fffffffffffffff0
R13: ffffffff8187340f R14: ffff88807730da00 R15: 0000000000000000
FS:  0000555569201500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000000013a2 CR3: 000000005dca2000 CR4: 00000000003506e0
Call Trace:
 <IRQ>
 kcov_remote_start_common include/linux/kcov.h:50 [inline]
 ieee80211_rx_list+0x813/0x32d0 net/mac80211/rx.c:5419
 ieee80211_rx_napi+0x1b2/0x3d0 net/mac80211/rx.c:5460
 ieee80211_rx include/net/mac80211.h:4971 [inline]
 ieee80211_handle_queued_frames+0x106/0x1a0 net/mac80211/main.c:319
 tasklet_action_common+0x302/0x4d0 kernel/softirq.c:809
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:preempt_schedule_irq+0xba/0x150 kernel/sched/core.c:7010
Code: 00 00 43 c6 44 37 04 f8 74 0b 0f 0b 48 f7 03 08 00 00 00 74 6f bf 01 00 00 00 e8 a1 ea cb f6 e8 4c fd fc f6 fb bf 01 00 00 00 <e8> f1 b4 ff ff 43 c6 44 37 08 00 48 c7 44 24 40 00 00 00 00 9c 8f
RSP: 0018:ffffc900034f7da0 EFLAGS: 00000286
RAX: f3889d328931f400 RBX: 0000000000000000 RCX: f3889d328931f400
RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: 0000000000000001
RBP: ffffc900034f7e50 R08: ffffffff8e8b666f R09: 1ffffffff1d16ccd
R10: dffffc0000000000 R11: fffffbfff1d16cce R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff9200069efb4
 irqentry_exit+0x67/0x70 kernel/entry/common.c:438
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:x64_sys_call+0x0/0x2030 arch/x86/entry/syscall_64.c:29
Code: 90 90 90 90 90 90 90 90 90 90 31 ed 65 48 8b 04 25 50 b6 03 00 48 8d a0 58 ff ff ff e8 59 9a 51 00 cc cc cc cc cc cc cc cc cc <66> 0f 1f 00 81 fe e2 00 00 00 7f 6e 83 fe 70 0f 8e d6 00 00 00 81
RSP: 0018:ffffc900034f7f18 EFLAGS: 00000206
RAX: ffffffffffffffff RBX: ffffc900034f7f20 RCX: 00000000000001c6
RDX: dffffc0000000000 RSI: 00000000000000ca RDI: ffffc900034f7f58
RBP: ffffc900034f7f48 R08: ffffffff8e8b666f R09: 1ffffffff1d16ccd
R10: dffffc0000000000 R11: fffffbfff1d16cce R12: 0000000000000000
R13: 0000000000000000 R14: ffffc900034f7f58 R15: 00000000000000ca
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f411559ce59
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:00007fffe5d5a938 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f411559ce59
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f4115815fac
RBP: 00000000000013a2 R08: 0000000000745a4d R09: 0000000000000000
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4115815fac R14: 00007f4115815fa8 R15: 00007f4115815fa0
 </TASK>

Crashes (21):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/14 21:45 linux-6.6.y 924b4a879cbb 1d2f3589 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2026/03/04 05:42 linux-6.6.y 7a137e9bfa0e 4180d919 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2025/11/19 04:49 linux-6.6.y 0a805b6ea8cd ef766cd7 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2026/06/14 19:11 linux-6.6.y 924b4a879cbb 1d2f3589 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2026/04/06 00:29 linux-6.6.y 08667c1437c0 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2026/04/05 01:31 linux-6.6.y 08667c1437c0 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2026/03/20 20:20 linux-6.6.y 4fc00fe35d46 ac6f1dff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2026/03/08 05:41 linux-6.6.y 4fc00fe35d46 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2026/03/04 08:02 linux-6.6.y 7a137e9bfa0e 4180d919 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2026/02/27 07:52 linux-6.6.y 7a137e9bfa0e a2f13f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2026/01/26 09:38 linux-6.6.y cbb31f77b879 55756628 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2026/01/11 15:06 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2026/01/06 08:08 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2026/01/05 02:52 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2025/12/18 21:33 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2025/12/16 19:41 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2025/12/16 00:50 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2025/11/26 12:19 linux-6.6.y 1e89a1be4fe9 64219f15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2025/10/10 14:21 linux-6.6.y e617101e5626 ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2025/08/28 14:10 linux-6.6.y bb9c90ab9c5a e12e5ba4 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
2025/08/25 11:35 linux-6.6.y bb9c90ab9c5a bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in irqentry_exit
* Struck through repros no longer work on HEAD.