================================================================== BUG: KCSAN: data-race in do_select / pollwake read to 0xffffc90000e139e0 of 4 bytes by task 15723 on cpu 1: poll_schedule_timeout fs/select.c:240 [inline] do_select+0xe48/0xf50 fs/select.c:603 core_sys_select+0x3d7/0x6e0 fs/select.c:677 do_pselect fs/select.c:759 [inline] __do_sys_pselect6 fs/select.c:802 [inline] __se_sys_pselect6+0x216/0x280 fs/select.c:793 __x64_sys_pselect6+0x78/0x90 fs/select.c:793 x64_sys_call+0x1caa/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:271 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f write to 0xffffc90000e139e0 of 4 bytes by interrupt on cpu 0: __pollwake fs/select.c:195 [inline] pollwake+0xb6/0x100 fs/select.c:215 __wake_up_common kernel/sched/wait.c:89 [inline] __wake_up_common_lock kernel/sched/wait.c:106 [inline] __wake_up+0x66/0xb0 kernel/sched/wait.c:127 bpf_ringbuf_notify+0x22/0x30 kernel/bpf/ringbuf.c:155 irq_work_single kernel/irq_work.c:221 [inline] irq_work_run_list kernel/irq_work.c:252 [inline] irq_work_run+0xdf/0x2d0 kernel/irq_work.c:261 __sysvec_irq_work+0x22/0x170 arch/x86/kernel/irq_work.c:22 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0x66/0x80 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:738 __wrmsrq arch/x86/include/asm/msr.h:80 [inline] native_write_msr arch/x86/include/asm/msr.h:137 [inline] wrmsrq arch/x86/include/asm/msr.h:199 [inline] native_apic_msr_write+0x3d/0x60 arch/x86/include/asm/apic.h:212 apic_write arch/x86/include/asm/apic.h:405 [inline] x2apic_send_IPI_self+0x10/0x20 arch/x86/kernel/apic/x2apic_phys.c:107 __apic_send_IPI_self arch/x86/include/asm/apic.h:455 [inline] arch_irq_work_raise+0x46/0x50 arch/x86/kernel/irq_work.c:31 irq_work_raise kernel/irq_work.c:84 [inline] __irq_work_queue_local+0x10f/0x2c0 kernel/irq_work.c:112 irq_work_queue+0x70/0x100 kernel/irq_work.c:124 bpf_ringbuf_commit kernel/bpf/ringbuf.c:-1 [inline] ____bpf_ringbuf_discard kernel/bpf/ringbuf.c:525 [inline] bpf_ringbuf_discard+0xd3/0xf0 kernel/bpf/ringbuf.c:523 bpf_prog_fe0ed97373b08409+0x4b/0x4f bpf_dispatcher_nop_func include/linux/bpf.h:1322 [inline] __bpf_prog_run include/linux/filter.h:718 [inline] bpf_prog_run include/linux/filter.h:725 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2258 [inline] bpf_trace_run3+0x10c/0x1d0 kernel/trace/bpf_trace.c:2300 __traceiter_kmem_cache_free+0x35/0x60 include/trace/events/kmem.h:114 __do_trace_kmem_cache_free include/trace/events/kmem.h:114 [inline] trace_kmem_cache_free include/trace/events/kmem.h:114 [inline] kmem_cache_free+0x257/0x300 mm/slub.c:4744 kfree_skbmem net/core/skbuff.c:-1 [inline] __kfree_skb+0x109/0x150 net/core/skbuff.c:1167 sk_skb_reason_drop+0xbd/0x270 net/core/skbuff.c:1204 kfree_skb_reason include/linux/skbuff.h:1275 [inline] ip_rcv_finish_core+0x5bb/0xb40 net/ipv4/ip_input.c:424 ip_list_rcv_finish net/ipv4/ip_input.c:609 [inline] ip_sublist_rcv+0x1f8/0x650 net/ipv4/ip_input.c:635 ip_list_rcv+0x261/0x290 net/ipv4/ip_input.c:669 __netif_receive_skb_list_ptype net/core/dev.c:6020 [inline] __netif_receive_skb_list_core+0x4dc/0x500 net/core/dev.c:6067 __netif_receive_skb_list net/core/dev.c:6119 [inline] netif_receive_skb_list_internal+0x487/0x600 net/core/dev.c:6210 netif_receive_skb_list+0x31/0x200 net/core/dev.c:6262 xdp_recv_frames net/bpf/test_run.c:280 [inline] xdp_test_run_batch net/bpf/test_run.c:361 [inline] bpf_test_run_xdp_live+0xdcb/0xfe0 net/bpf/test_run.c:390 bpf_prog_test_run_xdp+0x4f5/0x910 net/bpf/test_run.c:1322 bpf_prog_test_run+0x227/0x390 kernel/bpf/syscall.c:4429 __sys_bpf+0x3dc/0x790 kernel/bpf/syscall.c:5854 __do_sys_bpf kernel/bpf/syscall.c:5943 [inline] __se_sys_bpf kernel/bpf/syscall.c:5941 [inline] __x64_sys_bpf+0x41/0x50 kernel/bpf/syscall.c:5941 x64_sys_call+0x2478/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:322 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x00000001 -> 0x00000000 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 15719 Comm: syz.9.4370 Not tainted 6.16.0-rc1-syzkaller-00003-gf09079bd04a9 #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 ==================================================================