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BUG: KCSAN: data-race in __perf_event_overflow / __perf_event_set_bpf_prog

write to 0xffff88811b4af428 of 8 bytes by task 3563 on cpu 0:
 perf_event_set_bpf_handler kernel/events/core.c:10681 [inline]
 __perf_event_set_bpf_prog+0x419/0x470 kernel/events/core.c:11667
 _perf_ioctl kernel/events/core.c:6662 [inline]
 perf_ioctl+0x928/0x15c0 kernel/events/core.c:6722
 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/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811b4af428 of 8 bytes by interrupt on cpu 1:
 __perf_event_overflow+0x252/0x920 kernel/events/core.c:10739
 perf_event_overflow kernel/events/core.c:10823 [inline]
 perf_swevent_hrtimer+0x28d/0x310 kernel/events/core.c:12234
 __run_hrtimer kernel/time/hrtimer.c:1930 [inline]
 __hrtimer_run_queues+0x276/0x4f0 kernel/time/hrtimer.c:1994
 hrtimer_interrupt+0x261/0x850 kernel/time/hrtimer.c:2113
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 __sysvec_apic_timer_interrupt+0x5f/0x1c0 arch/x86/kernel/apic/apic.c:1067
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0x32/0x80 arch/x86/kernel/apic/apic.c:1061
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
 __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:95 [inline]
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:188 [inline]
 _raw_spin_unlock_irq+0x12/0x30 kernel/locking/spinlock.c:206
 expire_timers kernel/time/timer.c:1798 [inline]
 __run_timers kernel/time/timer.c:2374 [inline]
 __run_timer_base+0x405/0x5f0 kernel/time/timer.c:2386
 run_timer_base kernel/time/timer.c:2395 [inline]
 run_timer_softirq+0x31/0x70 kernel/time/timer.c:2405
 handle_softirqs+0xb9/0x280 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x42/0xd0 kernel/softirq.c:735
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0x74/0x80 arch/x86/kernel/apic/apic.c:1061
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
 __tsan_unaligned_write1+0x12/0x180 kernel/kcsan/core.c:1022
 mpage_write_folio fs/mpage.c:602 [inline]
 __mpage_writepages+0xa60/0x1390 fs/mpage.c:686
 mpage_writepages include/linux/mpage.h:27 [inline]
 fat_writepages+0x26/0x30 fs/fat/inode.c:200
 do_writepages+0x1c6/0x310 mm/page-writeback.c:2571
 filemap_writeback mm/filemap.c:388 [inline]
 filemap_fdatawrite_range mm/filemap.c:413 [inline]
 file_write_and_wait_range+0x178/0x2f0 mm/filemap.c:787
 mmb_fsync_noflush+0x48/0x140 fs/buffer.c:645
 fat_file_fsync+0x98/0x110 fs/fat/file.c:192
 vfs_fsync_range+0xc5/0xe0 fs/sync.c:186
 generic_write_sync include/linux/fs.h:2654 [inline]
 generic_file_write_iter+0x1ba/0x310 mm/filemap.c:4472
 iter_file_splice_write+0x6c4/0xa80 fs/splice.c:736
 do_splice_from fs/splice.c:936 [inline]
 direct_splice_actor+0x156/0x2a0 fs/splice.c:1159
 splice_direct_to_actor+0x311/0x670 fs/splice.c:1103
 do_splice_direct_actor fs/splice.c:1202 [inline]
 do_splice_direct+0x119/0x1a0 fs/splice.c:1228
 do_sendfile+0x382/0x650 fs/read_write.c:1372
 __do_sys_sendfile64 fs/read_write.c:1433 [inline]
 __se_sys_sendfile64 fs/read_write.c:1419 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1419
 x64_sys_call+0x2dc4/0x3020 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -> 0xffffc900017c4000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3538 Comm: syz.1.11 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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