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BUG: KCSAN: data-race in __htab_map_lookup_elem / bpf_lru_pop_free

write to 0xffff88811b217568 of 4 bytes by task 3582 on cpu 0:
 __local_list_add_pending kernel/bpf/bpf_lru_list.c:350 [inline]
 bpf_common_lru_pop_free kernel/bpf/bpf_lru_list.c:449 [inline]
 bpf_lru_pop_free+0xbea/0xcc0 kernel/bpf/bpf_lru_list.c:496
 prealloc_lru_pop kernel/bpf/hashtab.c:299 [inline]
 __htab_lru_percpu_map_update_elem+0xea/0x630 kernel/bpf/hashtab.c:1346
 bpf_percpu_hash_update+0x61/0xa0 kernel/bpf/hashtab.c:2400
 bpf_map_update_value+0x36b/0x570 kernel/bpf/syscall.c:270
 generic_map_update_batch+0x3eb/0x540 kernel/bpf/syscall.c:2038
 bpf_map_do_batch+0x25c/0x380 kernel/bpf/syscall.c:5647
 __sys_bpf+0x5f8/0x7c0 kernel/bpf/syscall.c:-1
 __do_sys_bpf kernel/bpf/syscall.c:6274 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6272 [inline]
 __x64_sys_bpf+0x41/0x50 kernel/bpf/syscall.c:6272
 x64_sys_call+0x28e1/0x3000 arch/x86/include/generated/asm/syscalls_64.h:322
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xca/0x2b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88811b217568 of 4 bytes by task 3554 on cpu 1:
 lookup_nulls_elem_raw kernel/bpf/hashtab.c:639 [inline]
 __htab_map_lookup_elem+0xab/0x150 kernel/bpf/hashtab.c:668
 htab_lru_percpu_map_lookup_elem+0x20/0xb0 kernel/bpf/hashtab.c:2334
 bpf_prog_1908f35e458ae2da+0x48/0x50
 bpf_dispatcher_nop_func include/linux/bpf.h:1378 [inline]
 __bpf_prog_run include/linux/filter.h:723 [inline]
 bpf_prog_run include/linux/filter.h:730 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline]
 bpf_trace_run2+0x107/0x1d0 kernel/trace/bpf_trace.c:2116
 __traceiter_kfree+0x2e/0x50 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+0x353/0x3c0 mm/slub.c:6865
 io_req_alloc_apoll io_uring/poll.c:653 [inline]
 io_arm_apoll+0x1b1/0x420 io_uring/poll.c:682
 io_arm_poll_handler+0x131/0x160 io_uring/poll.c:718
 io_queue_async+0x25d/0x2d0 io_uring/io_uring.c:2024
 io_queue_sqe io_uring/io_uring.c:2050 [inline]
 io_req_task_submit+0x9b/0xa0 io_uring/io_uring.c:1435
 io_handle_tw_list+0x1f7/0x230 io_uring/io_uring.c:1122
 tctx_task_work_run+0x42/0x160 io_uring/io_uring.c:1182
 tctx_task_work+0x3f/0x80 io_uring/io_uring.c:1200
 task_work_run+0x131/0x1a0 kernel/task_work.c:233
 get_signal+0xe12/0xf70 kernel/signal.c:2807
 arch_do_signal_or_restart+0x96/0x450 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x6a/0x740 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x1dd/0x2b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x9faea785 -> 0x2a6bb53a

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3554 Comm: syz.2.20 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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