syzbot

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BUG: KCSAN: data-race in __perf_event_overflow / perf_event_attach_bpf_prog

write to 0xffff88811ca18418 of 8 bytes by task 16702 on cpu 1:
 perf_event_attach_bpf_prog+0x138/0x1d0 kernel/trace/bpf_trace.c:1954
 __perf_event_set_bpf_prog+0x44d/0x470 kernel/events/core.c:11662
 _perf_ioctl kernel/events/core.c:6663 [inline]
 perf_ioctl+0x92e/0x15d0 kernel/events/core.c:6723
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xce/0x140 fs/ioctl.c:583
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:583
 x64_sys_call+0x1563/0x3020 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811ca18418 of 8 bytes by task 16670 on cpu 0:
 __perf_event_overflow+0x252/0x920 kernel/events/core.c:10700
 perf_swevent_overflow kernel/events/core.c:10842 [inline]
 perf_swevent_event+0x3f4/0x4d0 kernel/events/core.c:10903
 perf_tp_event+0x347/0x1660 kernel/events/core.c:11415
 perf_trace_run_bpf_submit+0xac/0x110 kernel/events/core.c:11334
 do_perf_trace_kfree include/trace/events/kmem.h:97 [inline]
 perf_trace_kfree+0xc2/0x100 include/trace/events/kmem.h:97
 __do_trace_kfree include/trace/events/kmem.h:97 [inline]
 trace_kfree include/trace/events/kmem.h:97 [inline]
 kfree+0x303/0x380 mm/slub.c:6469
 ___sys_recvmsg+0x135/0x3b0 net/socket.c:2855
 do_recvmmsg+0x1ef/0x560 net/socket.c:2949
 __sys_recvmmsg net/socket.c:3023 [inline]
 __do_sys_recvmmsg net/socket.c:3046 [inline]
 __se_sys_recvmmsg net/socket.c:3039 [inline]
 __x64_sys_recvmmsg+0xe5/0x170 net/socket.c:3039
 x64_sys_call+0x80f/0x3020 arch/x86/include/generated/asm/syscalls_64.h:300
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0xffffc900038b1000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 16670 Comm: syz.8.3768 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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