syzbot

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BUG: KCSAN: data-race in __perf_event_overflow / perf_event_attach_bpf_prog

write to 0xffff8881263274e8 of 8 bytes by task 667 on cpu 1:
 perf_event_attach_bpf_prog+0x138/0x1d0 kernel/trace/bpf_trace.c:1940
 __perf_event_set_bpf_prog+0x44c/0x470 kernel/events/core.c:11328
 _perf_ioctl kernel/events/core.c:6376 [inline]
 perf_ioctl+0x717/0x1350 kernel/events/core.c:6436
 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+0x14b0/0x3000 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc0/0x2a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff8881263274e8 of 8 bytes by task 413 on cpu 0:
 __perf_event_overflow+0x252/0x920 kernel/events/core.c:10401
 perf_swevent_overflow kernel/events/core.c:10536 [inline]
 perf_swevent_event+0x39e/0x450 kernel/events/core.c:10574
 perf_tp_event+0x30e/0xa00 kernel/events/core.c:11081
 perf_trace_run_bpf_submit+0xac/0x110 kernel/events/core.c:11005
 do_perf_trace_kmalloc include/trace/events/kmem.h:57 [inline]
 perf_trace_kmalloc+0xe4/0x110 include/trace/events/kmem.h:57
 __do_trace_kmalloc include/trace/events/kmem.h:57 [inline]
 trace_kmalloc include/trace/events/kmem.h:57 [inline]
 __do_kmalloc_node mm/slub.c:5658 [inline]
 __kmalloc_node_track_caller_noprof+0x515/0x590 mm/slub.c:5764
 kmalloc_reserve+0xdf/0x190 net/core/skbuff.c:608
 __alloc_skb+0x328/0x4b0 net/core/skbuff.c:690
 alloc_skb include/linux/skbuff.h:1383 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:818 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:875 [inline]
 nsim_dev_trap_report_work+0x18a/0x630 drivers/net/netdevsim/dev.c:921
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0x4cd/0x9d0 kernel/workqueue.c:3340
 worker_thread+0x581/0x770 kernel/workqueue.c:3421
 kthread+0x488/0x510 kernel/kthread.c:463
 ret_from_fork+0x148/0x280 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

value changed: 0x0000000000000000 -> 0xffffc90003b8b000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 413 Comm: kworker/u8:6 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound nsim_dev_trap_report_work
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