KASAN: stack-out-of-bounds Write in __hrtimer_run_queues

Status: upstream: reported C repro on 2026/11/15 08:26
Subsystems: kernel
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+c6b6d5e5800184a5fa86@syzkaller.appspotmail.com
First crash: 28d, last: 23m
▶ ▼ ✨ AI Jobs (3)
ID Workflow Result Correct Bug Created Started Finished Revision
552e1dad repro-c 💥 KASAN: stack-out-of-bounds Write in __hrtimer_run_queues 2026/10/23 14:11 2026/10/23 14:11 2026/10/24 05:10 1d9ca40b
2e5ced40 repro-c 💥 KASAN: stack-out-of-bounds Write in __hrtimer_run_queues 2026/10/21 11:26 2026/10/21 11:26 2026/10/21 14:07 61c200c7
99b56158 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ KASAN: stack-out-of-bounds Write in __hrtimer_run_queues 2026/10/20 00:51 2026/10/20 00:51 2026/10/20 01:41 e931f328
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [kernel?] KASAN: stack-out-of-bounds Write in __hrtimer_run_queues 0 (1) 2026/11/15 08:26
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: unable to handle kernel NULL pointer dereference in __hrtimer_run_queues kernel 10 syz, C 2 898d 894d 0/29 auto-obsoleted due to no activity on 2024/09/07 15:16
upstream general protection fault in __hrtimer_run_queues (3) kernel 17 syz, C error done 2 1070d 1235d 25/29 fixed on 2024/01/30 15:47
upstream Internal error in __hrtimer_run_queues kernel 2 1 796d 792d 0/29 auto-obsoleted due to no activity on 2024/12/08 21:40
upstream general protection fault in __hrtimer_run_queues kernel 2 syz, C 1 3052d 3052d 0/29 closed as invalid on 2018/07/07 21:38
upstream general protection fault in __hrtimer_run_queues (2) kernel 2 1 2872d 2872d 0/29 auto-closed as invalid on 2019/07/02 11:21

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 2 UID: 0 PID: 6558 Comm: syz.1.18 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:lookup_object lib/debugobjects.c:440 [inline]
RIP: 0010:debug_object_deactivate+0x19b/0x3b0 lib/debugobjects.c:938
Code: 48 c1 e8 03 42 80 3c 28 00 0f 85 8e 01 00 00 48 8b 1b 48 85 db 0f 84 32 01 00 00 48 8d 7b 18 41 83 c4 01 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 0f 85 4c 01 00 00 4c 3b 73 18 75 c2 48 b8 00 00 00
RSP: 0018:ffffc90000548da0 EFLAGS: 00010003
RAX: 0000000000000002 RBX: ffffffffffffffff RCX: 0000000000000002
RDX: ffffffff9cee70b0 RSI: 0000000000000004 RDI: 0000000000000017
RBP: ffffc90000548e80 R08: 0000000000000001 R09: fffff520000a91a2
R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000002
R13: dffffc0000000000 R14: ffffc9000635fd50 R15: 1ffff920000a91b6
FS:  0000000000000000(0000) GS:ffff888095472000(0063) knlGS:00000000f687eb40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000032963fff CR3: 000000006e2ab000 CR4: 0000000000352ef0
Call Trace:
 <IRQ>
 debug_hrtimer_deactivate kernel/time/hrtimer.c:491 [inline]
 __run_hrtimer kernel/time/hrtimer.c:2047 [inline]
 __hrtimer_run_queues+0x2e9/0x9a0 kernel/time/hrtimer.c:2136
 hrtimer_interrupt+0x441/0xaa0 kernel/time/hrtimer.c:2255
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
 __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:220 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:229
Code: 90 f3 0f 1e fa 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 fa 5a f7 f5 48 89 df e8 82 b1 f7 f5 e8 0d a9 24 f6 fb bf 01 00 00 00 <e8> d2 77 e6 f5 65 48 83 3d c1 52 c9 09 00 74 06 5b c3 cc cc cc cc
RSP: 0018:ffffc90002f3fc08 EFLAGS: 00000202
RAX: 00000000000001c1 RBX: ffffffff90cc6660 RCX: 0000000000000080
RDX: 0000000000000001 RSI: ffffffff8e627409 RDI: 0000000000000001
RBP: 0000000000000060 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880226f3000
R13: 0000000063702f73 R14: ffffffff8be2e420 R15: 000000000000009c
 pci_user_write_config_dword+0x150/0x230 drivers/pci/access.c:278
 proc_bus_pci_write+0x531/0x5e0 drivers/pci/proc.c:173
 pde_write fs/proc/inode.c:330 [inline]
 proc_reg_write+0x240/0x330 fs/proc/inode.c:342
 vfs_write+0x2aa/0x1040 fs/read_write.c:665
 ksys_write+0x12a/0x250 fs/read_write.c:719
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline]
 __do_fast_syscall_32+0x14d/0x8e0 arch/x86/entry/syscall_32.c:286
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:311
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7fc4fbc
Code: d2 74 05 c1 e8 0c 89 02 8b 5d fc 31 c0 c9 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 2e 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 58 b8
RSP: 002b:00000000f687e50c EFLAGS: 00000292 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080000300
RDX: 000000000000010f RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 000
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
   0:	48 c1 e8 03          	shr    $0x3,%rax
   4:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1)
   9:	0f 85 8e 01 00 00    	jne    0x19d
   f:	48 8b 1b             	mov    (%rbx),%rbx
  12:	48 85 db             	test   %rbx,%rbx
  15:	0f 84 32 01 00 00    	je     0x14d
  1b:	48 8d 7b 18          	lea    0x18(%rbx),%rdi
  1f:	41 83 c4 01          	add    $0x1,%r12d
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2f:	0f 85 4c 01 00 00    	jne    0x181
  35:	4c 3b 73 18          	cmp    0x18(%rbx),%r14
  39:	75 c2                	jne    0xfffffffd
  3b:	48                   	rex.W
  3c:	b8                   	.byte 0xb8
  3d:	00 00                	add    %al,(%rax)

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/11/15 08:25 git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 23c62304dde2 5c462c66 .config console log report C ci-qemu-upstream-386 general protection fault in __hrtimer_run_queues
2026/10/18 01:58 bpf-next 458575e1f2dd 432c0077 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce KASAN: stack-out-of-bounds Write in __hrtimer_run_queues
* Struck through repros no longer work on HEAD.