WARNING in irqentry_exit (2)

Status: upstream: reported C repro on 2026/08/05 00:13
Subsystems: kernel
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+93cc6b9a8a81c9e47978@syzkaller.appspotmail.com
First crash: 12d, last: 16h54m
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
1bfd7c64 repro-c Reproduced: ✅ WARNING in irqentry_exit (2) 2026/08/12 11:59 2026/08/12 11:59 2026/08/12 12:56 f8d35649
c5cacac5 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ WARNING in irqentry_exit (2) 2026/08/02 00:06 2026/08/02 00:06 2026/08/02 00:53 e611ffe1
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [kernel?] WARNING in irqentry_exit (2) 1 (3) 2026/08/12 13:33
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in irqentry_exit kernel -1 syz, C error done 2080 2130d 2197d 15/29 fixed on 2020/11/16 12:12
Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/08/12 13:13 19m nogikh@google.com upstream report job log log

Sample crash report:
------------[ cut here ]------------
__lockdep_enabled && this_cpu_read(hardirqs_enabled)
WARNING: ./include/linux/hrtimer_rearm.h:17 at hrtimer_test_and_clear_rearm_deferred_tif include/linux/hrtimer_rearm.h:17 [inline], CPU#0: syz-executor413/6031
WARNING: ./include/linux/hrtimer_rearm.h:17 at hrtimer_rearm_deferred_tif include/linux/hrtimer_rearm.h:52 [inline], CPU#0: syz-executor413/6031
WARNING: ./include/linux/hrtimer_rearm.h:17 at rseq_grant_slice_extension include/linux/rseq_entry.h:236 [inline], CPU#0: syz-executor413/6031
WARNING: ./include/linux/hrtimer_rearm.h:17 at __exit_to_user_mode_loop kernel/entry/common.c:54 [inline], CPU#0: syz-executor413/6031
WARNING: ./include/linux/hrtimer_rearm.h:17 at exit_to_user_mode_loop kernel/entry/common.c:101 [inline], CPU#0: syz-executor413/6031
WARNING: ./include/linux/hrtimer_rearm.h:17 at __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline], CPU#0: syz-executor413/6031
WARNING: ./include/linux/hrtimer_rearm.h:17 at irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline], CPU#0: syz-executor413/6031
WARNING: ./include/linux/hrtimer_rearm.h:17 at irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline], CPU#0: syz-executor413/6031
WARNING: ./include/linux/hrtimer_rearm.h:17 at irqentry_exit+0x718/0xa00 kernel/entry/common.c:165, CPU#0: syz-executor413/6031
Modules linked in:
CPU: 0 UID: 0 PID: 6031 Comm: syz-executor413 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:hrtimer_test_and_clear_rearm_deferred_tif include/linux/hrtimer_rearm.h:17 [inline]
RIP: 0010:hrtimer_rearm_deferred_tif include/linux/hrtimer_rearm.h:52 [inline]
RIP: 0010:rseq_grant_slice_extension include/linux/rseq_entry.h:236 [inline]
RIP: 0010:__exit_to_user_mode_loop kernel/entry/common.c:54 [inline]
RIP: 0010:exit_to_user_mode_loop kernel/entry/common.c:101 [inline]
RIP: 0010:__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
RIP: 0010:irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline]
RIP: 0010:irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline]
RIP: 0010:irqentry_exit+0x718/0xa00 kernel/entry/common.c:165
Code: 00 00 00 80 e8 79 f6 57 f6 fb 83 3d 55 fb 66 05 00 74 1a 65 8b 05 78 ba a8 08 85 c0 75 0f 65 8b 05 c9 b5 a8 08 85 c0 74 04 90 <0f> 0b 90 41 f7 c5 00 10 00 00 0f 84 74 fc ff ff f0 41 80 64 24 01
RSP: 0000:ffffc90005a8ff00 EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffffc90005a8ff48 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8e1a9419 RDI: ffffffff8c400480
RBP: ffffc90005a8ff38 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88802b490000
R13: 0000000000001010 R14: 0000001253cc57bd R15: 0000000000000000
FS:  000055555f665400(0000) GS:ffff8880d5dec000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f90fa2f5fe8 CR3: 000000003c93f000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0033:0x7f90fa3069ab
Code: 00 00 e8 f8 2e 00 00 45 31 c0 31 c9 31 c0 ba 01 00 00 00 be 02 00 00 00 bf 4f 00 00 00 e8 7d de 01 00 85 c0 75 0a c6 43 1c 01 <c6> 43 1c 01 eb f6 e8 0a 29 00 00 8b 38 e8 33 55 01 00 48 8d 3d 74
RSP: 002b:00007f90fa2f5ff0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 000055555f6677c0 RCX: 00007f90fa32482a
RDX: 0000000000000001 RSI: 0000000000000002 RDI: 000000000000004f
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff875f0e68
R13: 0000000000000002 R14: 00007f90fa3a7cc0 R15: 0000000000000002
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/12 13:33 upstream f5bbbfec59b4 aaffb173 .config console log report C ci-qemu-upstream WARNING in irqentry_exit
2026/07/31 08:38 upstream 3708dd948844 aaffb173 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in irqentry_exit
* Struck through repros no longer work on HEAD.