------------[ cut here ]------------
1
WARNING: kernel/rcu/tree_stall.h:1049 at rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1049, CPU#1: kworker/u8:4/57
Modules linked in:
CPU: 1 UID: 0 PID: 57 Comm: kworker/u8:4 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:rcu_check_gp_start_stall.part.0+0x1c4/0x4b0 kernel/rcu/tree_stall.h:1049
Code: 88 61 01 00 00 be 04 00 00 00 48 c7 c7 40 43 1a 9b e8 90 17 89 00 b8 01 00 00 00 87 05 e5 09 2d 19 85 c0 0f 85 3d 01 00 00 90 <0f> 0b 90 48 c7 c3 e4 cf d7 90 48 81 fd c0 08 7f 8e 74 5a 48 b8 00
RSP: 0018:ffffc90000a08de8 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000002904 RCX: ffffffff81ed3950
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff9b1a4340
RBP: ffffffff8e7f08c0 R08: 0000000000000001 R09: fffffbfff3634868
R10: 0000000000000003 R11: 0000000000000000 R12: 1ffffffff1c81e50
R13: 0000000000000246 R14: 0000000000000200 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888124475000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdbca1b4d58 CR3: 000000000e596000 CR4: 00000000003526f0
Call Trace:
rcu_check_gp_start_stall kernel/rcu/tree_stall.h:1012 [inline]
rcu_core+0x2cb/0x10d0 kernel/rcu/tree.c:2864
handle_softirqs+0x1ea/0xa00 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x162/0x210 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x59e/0x1700 kernel/smp.c:892
Code: c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 79 83 0c 00 f3 90 41 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 63 0f 00 00 8b 45 08 <31> ff 83 e0 01 41 89 c6 89 c6 e8 03 7e 0c 00 45 85 f6 75 d0 e8 49
RSP: 0018:ffffc900015e7870 EFLAGS: 00000246
RAX: 0000000000000011 RBX: 0000000000000000 RCX: ffffffff81fc0fcd
RDX: ffff88801f2a8000 RSI: ffffffff81fc0fa7 RDI: ffff88801f2a8000
RBP: ffff8880b8443320 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed1017088665 R14: 0000000000000001 R15: ffff8880b853c5c0
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057
on_each_cpu include/linux/smp.h:72 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline]
smp_text_poke_batch_finish+0x337/0xc60 arch/x86/kernel/alternative.c:2983
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
jump_label_update+0x37a/0x550 kernel/jump_label.c:910
static_key_enable_cpuslocked+0x1bc/0x270 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate mm/kfence/core.c:906 [inline]
toggle_allocation_gate+0xfe/0x2d0 mm/kfence/core.c:898
process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
process_scheduled_works kernel/workqueue.c:3385 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
----------------
Code disassembly (best guess):
0: c1 ed 03 shr $0x3,%ebp
3: 41 83 e4 07 and $0x7,%r12d
7: 49 01 c5 add %rax,%r13
a: 41 83 c4 03 add $0x3,%r12d
e: e8 79 83 0c 00 call 0xc838c
13: f3 90 pause
15: 41 0f b6 45 00 movzbl 0x0(%r13),%eax
1a: 41 38 c4 cmp %al,%r12b
1d: 7c 08 jl 0x27
1f: 84 c0 test %al,%al
21: 0f 85 63 0f 00 00 jne 0xf8a
27: 8b 45 08 mov 0x8(%rbp),%eax
* 2a: 31 ff xor %edi,%edi <-- trapping instruction
2c: 83 e0 01 and $0x1,%eax
2f: 41 89 c6 mov %eax,%r14d
32: 89 c6 mov %eax,%esi
34: e8 03 7e 0c 00 call 0xc7e3c
39: 45 85 f6 test %r14d,%r14d
3c: 75 d0 jne 0xe
3e: e8 .byte 0xe8
3f: 49 rex.WB