syzbot


WARNING in hrtimer_forward

Status: upstream: reported C repro on 2025/10/16 17:07
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+20af1bede69975f751dc@syzkaller.appspotmail.com
First crash: 67d, last: 66d
Fix bisection: failed (error log)
  
Bug presence (2)
Date Name Commit Repro Result
2025/10/18 linux-6.6.y (ToT) 0bbbd97a442d C [report] WARNING in hrtimer_forward
2025/10/18 upstream (ToT) f406055cb18c C Didn't crash
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in hrtimer_forward kernel -1 C done done 217 1430d 1915d 20/29 fixed on 2022/03/08 16:11
upstream WARNING in hrtimer_forward (4) kernel -1 3 91d 115d 0/29 upstream: reported on 2025/08/30 02:00
upstream WARNING in hrtimer_forward (2) kernel -1 1 627d 623d 0/29 auto-obsoleted due to no activity on 2024/07/14 02:37
upstream WARNING in hrtimer_forward (3) kernel -1 3 411d 505d 28/29 fixed on 2024/12/16 09:50

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 10729 at kernel/time/hrtimer.c:1071 hrtimer_forward+0x1d0/0x290 kernel/time/hrtimer.c:1071
Modules linked in:
CPU: 1 PID: 10729 Comm: syz.3.2187 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:hrtimer_forward+0x1d0/0x290 kernel/time/hrtimer.c:1071
Code: df e8 74 65 67 00 4c 89 33 48 8b 04 24 eb 07 e8 c6 0b 10 00 31 c0 48 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 b0 0b 10 00 <0f> 0b eb e6 48 89 e8 31 d2 49 f7 f4 48 89 04 24 49 89 c5 4d 0f af
RSP: 0018:ffffc900001f0c18 EFLAGS: 00010246
RAX: ffffffff81757f20 RBX: ffff88807e78f1c0 RCX: ffff88802c80bc00
RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 000000000152712b R08: ffffffff90da7507 R09: 1ffffffff21b4ea0
R10: dffffc0000000000 R11: fffffbfff21b4ea1 R12: 0000000000000001
R13: 00000000061a8000 R14: 1ffff1100fcf1e3b R15: ffff88807e78f1d8
FS:  00007f2f5ed466c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa98fdb12f8 CR3: 0000000019ff2000 CR4: 00000000003506e0
Call Trace:
 <IRQ>
 hrtimer_forward_now include/linux/hrtimer.h:509 [inline]
 mac80211_hwsim_beacon+0x164/0x1b0 drivers/net/wireless/virtual/mac80211_hwsim.c:2304
 __run_hrtimer kernel/time/hrtimer.c:1750 [inline]
 __hrtimer_run_queues+0x51e/0xc40 kernel/time/hrtimer.c:1814
 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1831
 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+0xc7/0x190 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:trace_event_get_offsets_lock_acquire include/trace/events/lock.h:-1 [inline]
RIP: 0010:perf_trace_lock_acquire+0xb6/0x3e0 include/trace/events/lock.h:24
Code: 00 00 00 00 00 00 48 89 74 24 30 48 8d 5e 18 48 89 d8 48 c1 e8 03 48 89 44 24 20 42 80 3c 20 00 74 08 48 89 df e8 1a c0 76 00 <48> 89 5c 24 28 48 8b 03 48 85 c0 48 c7 c7 60 a8 aa 8a 48 0f 45 f8
RSP: 0018:ffffc9000c18f4c0 EFLAGS: 00000246
RAX: 1ffff11002f0cc12 RBX: ffff888017866090 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff888017866078 RDI: ffffffff8cbfb0c0
RBP: ffffc9000c18f5c0 R08: 0000000000000000 R09: 0000000000000001
R10: dffffc0000000000 R11: fffffbfff1c950ae R12: dffffc0000000000
R13: ffff888017866078 R14: ffffffff8cbfb0c0 R15: 1ffff92001831ea0
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x3e2/0x410 kernel/locking/lockdep.c:5725
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 __pte_offset_map_lock+0x107/0x1e0 mm/pgtable-generic.c:375
 get_locked_pte include/linux/mm.h:2741 [inline]
 __text_poke+0x29b/0xb20 arch/x86/kernel/alternative.c:2036
 text_poke arch/x86/kernel/alternative.c:2121 [inline]
 text_poke_bp_batch+0x4e4/0x930 arch/x86/kernel/alternative.c:2454
 text_poke_flush arch/x86/kernel/alternative.c:2623 [inline]
 text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2630
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x123/0x240 kernel/jump_label.c:207
 static_key_enable+0x1a/0x20 kernel/jump_label.c:220
 tracepoint_add_func+0x83b/0x9a0 kernel/tracepoint.c:361
 tracepoint_probe_register_prio kernel/tracepoint.c:511 [inline]
 tracepoint_probe_register+0x5e/0x90 kernel/tracepoint.c:531
 perf_trace_event_reg kernel/trace/trace_event_perf.c:129 [inline]
 perf_trace_event_init+0x4d2/0x9b0 kernel/trace/trace_event_perf.c:202
 perf_trace_init+0x238/0x2d0 kernel/trace/trace_event_perf.c:226
 perf_tp_event_init+0x8d/0x110 kernel/events/core.c:10203
 perf_try_init_event+0x12b/0x3c0 kernel/events/core.c:11817
 perf_init_event kernel/events/core.c:11887 [inline]
 perf_event_alloc+0xfa4/0x21b0 kernel/events/core.c:12168
 __do_sys_perf_event_open kernel/events/core.c:12675 [inline]
 __se_sys_perf_event_open+0x70e/0x1c20 kernel/events/core.c:12566
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2f5df8eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2f5ed46038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f2f5e1e5fa0 RCX: 00007f2f5df8eec9
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000200000000040
RBP: 00007f2f5e011f91 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f5e1e6038 R14: 00007f2f5e1e5fa0 R15: 00007fff46ce5a08
 </TASK>
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	00 00                	add    %al,(%rax)
   4:	00 00                	add    %al,(%rax)
   6:	48 89 74 24 30       	mov    %rsi,0x30(%rsp)
   b:	48 8d 5e 18          	lea    0x18(%rsi),%rbx
   f:	48 89 d8             	mov    %rbx,%rax
  12:	48 c1 e8 03          	shr    $0x3,%rax
  16:	48 89 44 24 20       	mov    %rax,0x20(%rsp)
  1b:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1)
  20:	74 08                	je     0x2a
  22:	48 89 df             	mov    %rbx,%rdi
  25:	e8 1a c0 76 00       	call   0x76c044
* 2a:	48 89 5c 24 28       	mov    %rbx,0x28(%rsp) <-- trapping instruction
  2f:	48 8b 03             	mov    (%rbx),%rax
  32:	48 85 c0             	test   %rax,%rax
  35:	48 c7 c7 60 a8 aa 8a 	mov    $0xffffffff8aaaa860,%rdi
  3c:	48 0f 45 f8          	cmovne %rax,%rdi

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/16 17:06 linux-6.6.y 0bbbd97a442d 19568248 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf WARNING in hrtimer_forward
* Struck through repros no longer work on HEAD.