------------[ cut here ]------------
WARNING: CPU: 0 PID: 1103 at kernel/rcu/tree_stall.h:1050 rcu_check_gp_start_stall+0x2e4/0x470 kernel/rcu/tree_stall.h:1050
Modules linked in:
CPU: 0 UID: 0 PID: 1103 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:rcu_check_gp_start_stall+0x2e4/0x470 kernel/rcu/tree_stall.h:1050
Code: ff ff 48 c7 c7 20 74 b0 99 be 04 00 00 00 e8 53 e0 7c 00 4c 89 f7 b8 01 00 00 00 87 05 15 67 09 18 85 c0 0f 85 17 ff ff ff 90 <0f> 0b 90 48 81 ff 80 f4 13 8e 74 47 48 c7 c0 60 e6 a3 8f 48 c1 e8
RSP: 0018:ffffc90000007bb8 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000a02 RCX: ffffffff81a70cfd
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff8e13f480
RBP: ffffc90000007e30 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff3360e84 R12: 0000000000002904
R13: 1ffff110170c75f2 R14: ffffffff8e13f480 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888125c11000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 000000000df36000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000082
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
rcu_core+0x5fa/0x1770 kernel/rcu/tree.c:2856
handle_softirqs+0x283/0x870 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:check_kcov_mode kernel/kcov.c:194 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x70 kernel/kcov.c:217
Code: 08 f0 a0 92 65 8b 15 78 2a e1 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 3c 16 00 00 00 74 2c 8b 91 18 16 00 00 <83> fa 02 75 21 48 8b 91 20 16 00 00 48 8b 32 48 8d 7e 01 8b 89 1c
RSP: 0018:ffffc90003c8f658 EFLAGS: 00000246
RAX: ffffffff81b4665b RBX: 1ffff110170e7f61 RCX: ffff888026c88000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003c8f7e0 R08: ffffffff8fa3b537 R09: 1ffffffff1f476a6
R10: dffffc0000000000 R11: fffffbfff1f476a7 R12: ffff8880b873fb08
R13: dffffc0000000000 R14: ffff8880b863b1c0 R15: 0000000000000001
csd_lock_wait kernel/smp.c:342 [inline]
smp_call_function_many_cond+0xd4b/0x12d0 kernel/smp.c:877
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2653 [inline]
smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2863
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:850
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
----------------
Code disassembly (best guess):
0: 08 f0 or %dh,%al
2: a0 92 65 8b 15 78 2a movabs 0x10e12a78158b6592,%al
9: e1 10
b: 81 e2 00 01 ff 00 and $0xff0100,%edx
11: 74 11 je 0x24
13: 81 fa 00 01 00 00 cmp $0x100,%edx
19: 75 35 jne 0x50
1b: 83 b9 3c 16 00 00 00 cmpl $0x0,0x163c(%rcx)
22: 74 2c je 0x50
24: 8b 91 18 16 00 00 mov 0x1618(%rcx),%edx
* 2a: 83 fa 02 cmp $0x2,%edx <-- trapping instruction
2d: 75 21 jne 0x50
2f: 48 8b 91 20 16 00 00 mov 0x1620(%rcx),%rdx
36: 48 8b 32 mov (%rdx),%rsi
39: 48 8d 7e 01 lea 0x1(%rsi),%rdi
3d: 8b .byte 0x8b
3e: 89 .byte 0x89
3f: 1c .byte 0x1c