------------[ cut here ]------------ !atomic_long_inc_not_zero(&event->refcount) WARNING: kernel/events/core.c:10438 at __perf_event_overflow+0xb9e/0xec0 kernel/events/core.c:10438, CPU#1: syz.0.1995/12350 Modules linked in: CPU: 1 UID: 0 PID: 12350 Comm: syz.0.1995 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:10438 Code: 81 36 00 4d 89 3e 4c 8b 7c 24 10 e9 c2 fc ff ff e8 c7 a2 cd ff 49 bd 00 00 00 00 00 fc ff df e9 08 fe ff ff e8 b3 a2 cd ff 90 <0f> 0b 90 e9 21 ff ff ff e8 a5 a2 cd ff 48 c7 c7 80 15 b7 8b e8 a9 RSP: 0018:ffffc9000d467140 EFLAGS: 00010293 RAX: ffffffff81f6d38d RBX: ffff88802feda6b0 RCX: ffff88807ae9bd00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000d467250 R08: ffff88802feda807 R09: 1ffff11005fdb500 R10: dffffc0000000000 R11: ffffed1005fdb501 R12: ffff88802feda5b0 R13: dffffc0000000000 R14: ffff88802feda800 R15: 0000000000000000 FS: 00007fbe39dd76c0(0000) GS:ffff8881257f8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000002000 CR3: 000000007956e000 CR4: 00000000003526f0 Call Trace: perf_swevent_overflow kernel/events/core.c:10536 [inline] perf_swevent_event+0x323/0x650 kernel/events/core.c:-1 do_perf_sw_event kernel/events/core.c:10676 [inline] ___perf_sw_event+0x4a6/0x730 kernel/events/core.c:10703 __perf_sw_event+0xf9/0x1a0 kernel/events/core.c:10715 perf_sw_event include/linux/perf_event.h:1596 [inline] do_user_addr_fault+0x12c4/0x1360 arch/x86/mm/fault.c:1283 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0010:rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:74 Code: 44 04 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 db 83 f9 08 73 e8 eb c5 a4 e9 cf 44 04 00 48 8b 06 48 89 07 48 8d 47 08 48 83 e0 f8 48 RSP: 0018:ffffc9000d467758 EFLAGS: 00050206 RAX: 00007ffffffff001 RBX: ffff88805b5c0000 RCX: 0000000000032020 RDX: 0000000000000001 RSI: 0000200000002000 RDI: ffff88805b5c1fc0 RBP: ffffc9000d4678b0 R08: ffff88805b5f3fdf R09: 1ffff1100b6be7fb R10: dffffc0000000000 R11: ffffed100b6be7fc R12: ffffc9000d467df8 R13: 0000200000000040 R14: 0000000000033fe0 R15: 1ffff92001a8cfbf copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:141 [inline] copy_from_user_iter lib/iov_iter.c:67 [inline] iterate_ubuf include/linux/iov_iter.h:30 [inline] iterate_and_advance2 include/linux/iov_iter.h:302 [inline] iterate_and_advance include/linux/iov_iter.h:330 [inline] __copy_from_iter lib/iov_iter.c:261 [inline] _copy_from_iter+0x21b/0x1670 lib/iov_iter.c:272 copy_from_iter include/linux/uio.h:228 [inline] copy_from_iter_full include/linux/uio.h:245 [inline] memcpy_from_msg include/linux/skbuff.h:4272 [inline] netlink_sendmsg+0x6c0/0xb40 net/netlink/af_netlink.c:1879 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa68/0xad0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681 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: 0033:0x7fbe38f9a379 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:00007fbe39dd7028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fbe391e5fa0 RCX: 00007fbe38f9a379 RDX: 3500000000000000 RSI: 0000200000000000 RDI: 0000000000000005 RBP: 00007fbe3902dd68 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbe391e6038 R14: 00007fbe391e5fa0 R15: 00007ffcd9275858 ---------------- Code disassembly (best guess): 0: 44 04 00 rex.R add $0x0,%al 3: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) a: 00 00 00 d: 0f 1f 00 nopl (%rax) 10: 48 8b 06 mov (%rsi),%rax 13: 48 89 07 mov %rax,(%rdi) 16: 48 83 c6 08 add $0x8,%rsi 1a: 48 83 c7 08 add $0x8,%rdi 1e: 83 e9 08 sub $0x8,%ecx 21: 74 db je 0xfffffffe 23: 83 f9 08 cmp $0x8,%ecx 26: 73 e8 jae 0x10 28: eb c5 jmp 0xffffffef * 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2c: e9 cf 44 04 00 jmp 0x44500 31: 48 8b 06 mov (%rsi),%rax 34: 48 89 07 mov %rax,(%rdi) 37: 48 8d 47 08 lea 0x8(%rdi),%rax 3b: 48 83 e0 f8 and $0xfffffffffffffff8,%rax 3f: 48 rex.W