rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (8436 ticks this GP) idle=2dcc/1/0x4000000000000000 softirq=39836/39837 fqs=4406 rcu: hardirqs softirqs csw/system rcu: number: 1331070 4 0 rcu: cputime: 17219 35269 71 ==> 52490(ms) rcu: (t=10500 jiffies g=51389 q=2134 ncpus=2) CPU: 1 PID: 11946 Comm: syz.0.1660 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:212 Code: 00 0f 0b 0f 1f 80 00 00 00 00 f3 0f 1e fa 53 48 89 fb e8 13 00 00 00 48 8b 3d 9c 92 c4 0c 48 89 de 5b e9 43 9d 56 00 cc cc cc 0f 1e fa 48 8b 04 24 65 48 8b 0d f0 24 7e 7e 65 8b 15 f1 24 7e RSP: 0018:ffffc900001f0490 EFLAGS: 00000292 RAX: fffffffffffffff0 RBX: ffffffff8f48a837 RCX: 0000000000000003 RDX: ffffc900001f0608 RSI: ffffc900001f0a70 RDI: ffffc900001f05c8 RBP: dffffc0000000000 R08: ffff888026ebda00 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000100 R12: ffffc900001f05c8 R13: dffffc0000000000 R14: ffffffff8f48a836 R15: ffffc900001f05c8 FS: 00007fd6a69836c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d40dff8 CR3: 000000001f766000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: deref_stack_reg+0x29/0x240 arch/x86/kernel/unwind_orc.c:402 unwind_next_frame+0x1789/0x2970 arch/x86/kernel/unwind_orc.c:648 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 __kfence_alloc+0x29a/0x3a0 mm/kfence/core.c:1101 kfence_alloc include/linux/kfence.h:129 [inline] slab_alloc_node mm/slub.c:3481 [inline] kmem_cache_alloc_node+0x2c0/0x330 mm/slub.c:3540 __alloc_skb+0x108/0x2c0 net/core/skbuff.c:643 alloc_skb include/linux/skbuff.h:1284 [inline] new_skb drivers/block/aoe/aoecmd.c:66 [inline] aoecmd_cfg_pkts drivers/block/aoe/aoecmd.c:430 [inline] aoecmd_cfg+0x29c/0xa00 drivers/block/aoe/aoecmd.c:1374 call_timer_fn+0x16e/0x530 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x52d/0x7d0 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 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 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:generic_exec_single+0x476/0x4f0 kernel/smp.c:418 Code: 75 11 e8 cd e6 0a 00 48 85 db 75 16 e8 c3 e6 0a 00 eb 15 e8 bc e6 0a 00 e8 47 cd ec 08 48 85 db 74 ea e8 ad e6 0a 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 04 2c 00 00 00 00 66 43 c7 44 2c RSP: 0018:ffffc900036bfa00 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000080000 RDX: ffffc9000bfd9000 RSI: 00000000000043c7 RDI: 00000000000043c8 RBP: ffffc900036bfad0 R08: ffffffff90d945ff R09: 1ffffffff21b28bf R10: dffffc0000000000 R11: fffffbfff21b28c0 R12: 1ffff920006d7f44 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff920006d7f65 smp_call_function_single+0x352/0x580 kernel/smp.c:647 task_function_call kernel/events/core.c:120 [inline] perf_install_in_context+0x591/0x8e0 kernel/events/core.c:2948 __do_sys_perf_event_open kernel/events/core.c:12915 [inline] __se_sys_perf_event_open+0x17fa/0x1c20 kernel/events/core.c:12567 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: 0033:0x7fd6a5b8f749 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:00007fd6a6983038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007fd6a5de5fa0 RCX: 00007fd6a5b8f749 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000140 RBP: 00007fd6a5c13f91 R08: 0000000000000002 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd6a5de6038 R14: 00007fd6a5de5fa0 R15: 00007ffffcf703c8