From: syzbot <syzbot+9d17de59c48d71bd6824@syzkaller.appspotmail.com>
To: bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com,
linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org,
mingo@redhat.com, syzkaller-bugs@googlegroups.com,
tglx@kernel.org, tony.luck@intel.com, x86@kernel.org
Subject: Re: [syzbot] [edac?] WARNING in mce_timer_fn
Date: Sat, 17 Oct 2026 05:23:42 -0700 [thread overview]
Message-ID: <6ad368ce.a6d1a155.34a93f.0014.GAE@google.com> (raw)
In-Reply-To: <6a6cd87b.2d659fcc.1d46f5.019c.GAE@google.com>
syzbot has found a reproducer for the following issue on:
HEAD commit: 70dd4ee72eb2 Merge tag 'pinctrl-v7.3-3' of git://git.kerne..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=114c8031580000
kernel config: https://syzkaller.appspot.com/x/.config?x=129d675874dbf896
dashboard link: https://syzkaller.appspot.com/bug?extid=9d17de59c48d71bd6824
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1391efd1580000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9d17de59c48d71bd6824@syzkaller.appspotmail.com
------------[ cut here ]------------
cpu_t != t
WARNING: arch/x86/kernel/cpu/mce/core.c:1770 at mce_timer_fn+0x289/0x2e0 arch/x86/kernel/cpu/mce/core.c:1770, CPU#0: udevd/4970
Modules linked in:
CPU: 0 UID: 0 PID: 4970 Comm: udevd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
RIP: 0010:mce_timer_fn+0x289/0x2e0 arch/x86/kernel/cpu/mce/core.c:1770
Code: 59 00 4d 01 e4 4d 39 ec 4d 0f 47 e5 31 ff 4c 89 e6 e8 6b 40 59 00 4d 85 e4 0f 84 20 ff ff ff e9 f7 fe ff ff e8 b8 45 59 00 90 <0f> 0b 90 e9 cf fd ff ff 4c 89 f6 48 c7 c7 a0 ef bf 8f e8 60 dc 84
RSP: 0018:ffffc90000007c20 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880b8223440 RCX: 0000000000000100
RDX: ffff88807cbccb00 RSI: ffffffff81b311b8 RDI: ffffffff8e6af920
RBP: ffff8880b8323440 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000100 R14: 1ffff92000000f8d R15: ffffffff81b30f30
FS: 00007fa1f48b4880(0000) GS:ffff888122946000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563a7ab14be0 CR3: 000000007be29000 CR4: 00000000003526f0
Call Trace:
<IRQ>
call_timer_fn+0x198/0x5f0 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers+0x757/0xb00 kernel/time/timer.c:2374
__run_timer_base kernel/time/timer.c:2386 [inline]
__run_timer_base kernel/time/timer.c:2378 [inline]
run_timer_base+0x114/0x190 kernel/time/timer.c:2395
run_timer_softirq+0x10/0x50 kernel/time/timer.c:2403
handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645
__do_softirq kernel/softirq.c:679 [inline]
invoke_softirq kernel/softirq.c:519 [inline]
__irq_exit_rcu+0x16a/0x210 kernel/softirq.c:758
irq_exit_rcu+0x9/0x30 kernel/softirq.c:775
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa3/0xc0 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:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline]
RIP: 0010:lock_acquire kernel/locking/lockdep.c:5938 [inline]
RIP: 0010:lock_acquire+0x166/0x380 kernel/locking/lockdep.c:5899
Code: d5 00 00 00 65 8b 05 61 63 a6 13 85 c0 0f 85 c6 00 00 00 65 48 8b 05 91 1c a6 13 8b 90 a4 0b 00 00 85 d2 0f 85 b0 00 00 00 9c <8f> 04 24 fa 48 c7 c7 49 a7 4d 8e e8 6a 07 ed 09 45 89 e8 44 89 f6
RSP: 0018:ffffc90004e9f578 EFLAGS: 00000246
RAX: ffff88807cbccb00 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff81b9c261 RDI: fffffbfff1fbd8bc
RBP: ffffffff8fdec5e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000200 R11: 000000000000b9e5 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
rcu_read_lock include/linux/rcupdate.h:849 [inline]
class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495
__unwind_start+0x3cd/0x7e0 arch/x86/kernel/unwind_orc.c:787
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0x73/0xf0 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5414 [inline]
__kmalloc_noprof+0x32f/0x840 mm/slub.c:5439
_kmalloc_noprof include/linux/slab.h:995 [inline]
tomoyo_realpath_from_path+0xb6/0x690 security/tomoyo/realpath.c:251
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_perm+0x276/0x460 security/tomoyo/file.c:827
security_inode_getattr+0x116/0x280 security/security.c:1895
vfs_getattr fs/stat.c:259 [inline]
vfs_fstat+0x4b/0xe0 fs/stat.c:281
__do_sys_newfstat+0x8b/0x110 fs/stat.c:551
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa1f4111ad7
Code: 73 01 c3 48 8b 0d 21 f3 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 05 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8
RSP: 002b:00007ffe5cd40ab8 EFLAGS: 00000206 ORIG_RAX: 0000000000000005
RAX: ffffffffffffffda RBX: 000000000000000d RCX: 00007fa1f4111ad7
RDX: 0000000000090800 RSI: 00007ffe5cd40ac0 RDI: 000000000000000d
RBP: 00007ffe5cd40ac0 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000206 R12: 00005592845d9170
R13: 00000000000000ff R14: 000055926871bbe0 R15: 00007ffe5cd40e10
</TASK>
----------------
Code disassembly (best guess):
0: d5 00 00 00 {rex2 0x0} add %al,(%rax)
4: 65 8b 05 61 63 a6 13 mov %gs:0x13a66361(%rip),%eax # 0x13a6636c
b: 85 c0 test %eax,%eax
d: 0f 85 c6 00 00 00 jne 0xd9
13: 65 48 8b 05 91 1c a6 mov %gs:0x13a61c91(%rip),%rax # 0x13a61cac
1a: 13
1b: 8b 90 a4 0b 00 00 mov 0xba4(%rax),%edx
21: 85 d2 test %edx,%edx
23: 0f 85 b0 00 00 00 jne 0xd9
29: 9c pushf
* 2a: 8f 04 24 pop (%rsp) <-- trapping instruction
2d: fa cli
2e: 48 c7 c7 49 a7 4d 8e mov $0xffffffff8e4da749,%rdi
35: e8 6a 07 ed 09 call 0x9ed07a4
3a: 45 89 e8 mov %r13d,%r8d
3d: 44 89 f6 mov %r14d,%esi
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
prev parent reply other threads:[~2026-10-17 12:23 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-31 17:16 syzbot
2026-07-31 18:23 ` Borislav Petkov
2026-10-17 12:23 ` syzbot [this message]
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