------------[ cut here ]------------ !atomic_long_inc_not_zero(&event->refcount) WARNING: kernel/events/core.c:10447 at __perf_event_overflow+0xb9e/0xec0 kernel/events/core.c:10447, CPU#1: syz.4.1930/14103 Modules linked in: CPU: 1 UID: 0 PID: 14103 Comm: syz.4.1930 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:__perf_event_overflow+0xb9e/0xec0 kernel/events/core.c:10447 Code: 93 36 00 4d 89 3e 4c 8b 7c 24 10 e9 c2 fc ff ff e8 87 42 ce ff 49 bd 00 00 00 00 00 fc ff df e9 08 fe ff ff e8 73 42 ce ff 90 <0f> 0b 90 e9 21 ff ff ff e8 65 42 ce ff 48 c7 c7 20 12 b7 8b e8 89 RSP: 0018:ffffc9000f517840 EFLAGS: 00010287 RAX: ffffffff81f637ad RBX: ffff888020750100 RCX: 0000000000080000 RDX: ffffc90010464000 RSI: 0000000000000065 RDI: 0000000000000066 RBP: ffffc9000f517950 R08: ffff888020750257 R09: 1ffff110040ea04a R10: dffffc0000000000 R11: ffffed10040ea04b R12: ffff888020750000 R13: dffffc0000000000 R14: ffff888020750250 R15: 0000000000000000 FS: 00007f12dee4a6c0(0000) GS:ffff8881257f3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000029d16000 CR4: 00000000003526f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: perf_swevent_overflow kernel/events/core.c:10545 [inline] perf_swevent_event+0x323/0x650 kernel/events/core.c:-1 do_perf_sw_event kernel/events/core.c:10685 [inline] ___perf_sw_event+0x4a6/0x730 kernel/events/core.c:10712 __perf_sw_event+0xf9/0x1a0 kernel/events/core.c:10724 perf_sw_event include/linux/perf_event.h:1596 [inline] do_user_addr_fault+0x12c4/0x1360 arch/x86/mm/fault.c:1281 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0010:__put_user_4+0xd/0x20 arch/x86/lib/putuser.S:94 Code: 66 89 01 31 c9 0f 01 ca c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 89 cb 48 c1 fb 3f 48 09 d9 0f 01 cb <89> 01 31 c9 0f 01 ca c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc9000f517e50 EFLAGS: 00050246 RAX: 0000000000000007 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8df350bb RDI: ffffffff8c073b00 RBP: 0000000000000007 R08: ffffffff82139a5f R09: ffff888011a32800 R10: dffffc0000000000 R11: ffffed1006900f21 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000005 __sys_socketpair+0xb7/0x560 net/socket.c:1797 __do_sys_socketpair net/socket.c:1863 [inline] __se_sys_socketpair net/socket.c:1860 [inline] __x64_sys_socketpair+0x9b/0xb0 net/socket.c:1860 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f12ddf9aeb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f12dee4a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000035 RAX: ffffffffffffffda RBX: 00007f12de215fa0 RCX: 00007f12ddf9aeb9 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000001 RBP: 00007f12de008c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f12de216038 R14: 00007f12de215fa0 R15: 00007fffa2090db8 ---------------- Code disassembly (best guess): 0: 66 89 01 mov %ax,(%rcx) 3: 31 c9 xor %ecx,%ecx 5: 0f 01 ca clac 8: c3 ret 9: cc int3 a: cc int3 b: cc int3 c: cc int3 d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 48 89 cb mov %rcx,%rbx 20: 48 c1 fb 3f sar $0x3f,%rbx 24: 48 09 d9 or %rbx,%rcx 27: 0f 01 cb stac * 2a: 89 01 mov %eax,(%rcx) <-- trapping instruction 2c: 31 c9 xor %ecx,%ecx 2e: 0f 01 ca clac 31: c3 ret 32: cc int3 33: cc int3 34: cc int3 35: cc int3 36: 90 nop 37: 90 nop 38: 90 nop 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop