------------[ cut here ]------------ WARNING: CPU: 0 PID: 12737 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: 12737 Comm: syz.5.1749 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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: 000055556f985500(0000) GS:ffff888125c11000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c352901 CR3: 000000003072c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 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:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_single+0x3a9/0x590 kernel/smp.c:687 Code: 33 44 89 f6 83 e6 01 31 ff e8 83 7a 0b 00 41 83 e6 01 75 11 e8 38 76 0b 00 4d 89 fe eb 3f e8 2e 76 0b 00 eb 3c 4d 89 fe f3 90 <43> 0f b6 04 2c 84 c0 75 0f f7 03 01 00 00 00 74 1d e8 11 76 0b 00 RSP: 0018:ffffc9000cca7a40 EFLAGS: 00000293 RAX: ffffffff81b44f8f RBX: ffffc9000cca7a88 RCX: ffff88802ee05a00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000cca7b30 R08: ffffffff8fa3b537 R09: 1ffffffff1f476a6 R10: dffffc0000000000 R11: ffffffff81706100 R12: 1ffff92001994f51 R13: dffffc0000000000 R14: 1ffff92001994f4c R15: 1ffff92001994f4c task_function_call kernel/events/core.c:121 [inline] event_function_call+0x326/0x970 kernel/events/core.c:341 perf_event_release_kernel+0x15d/0x510 kernel/events/core.c:5801 perf_release+0x38/0x50 kernel/events/core.c:5876 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3c0198eec9 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:00007fffbf7ec9e8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f3c01be7da0 RCX: 00007f3c0198eec9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f3c01be7da0 R08: 0000000000000200 R09: 0000001dbf7eccdf R10: 00007f3c01be7cb0 R11: 0000000000000246 R12: 000000000005c517 R13: 00007f3c01be6360 R14: ffffffffffffffff R15: 00007fffbf7ecb00 ---------------- Code disassembly (best guess): 0: 33 44 89 f6 xor -0xa(%rcx,%rcx,4),%eax 4: 83 e6 01 and $0x1,%esi 7: 31 ff xor %edi,%edi 9: e8 83 7a 0b 00 call 0xb7a91 e: 41 83 e6 01 and $0x1,%r14d 12: 75 11 jne 0x25 14: e8 38 76 0b 00 call 0xb7651 19: 4d 89 fe mov %r15,%r14 1c: eb 3f jmp 0x5d 1e: e8 2e 76 0b 00 call 0xb7651 23: eb 3c jmp 0x61 25: 4d 89 fe mov %r15,%r14 28: f3 90 pause * 2a: 43 0f b6 04 2c movzbl (%r12,%r13,1),%eax <-- trapping instruction 2f: 84 c0 test %al,%al 31: 75 0f jne 0x42 33: f7 03 01 00 00 00 testl $0x1,(%rbx) 39: 74 1d je 0x58 3b: e8 11 76 0b 00 call 0xb7651