================================================================== BUG: KCSAN: data-race in do_select / pollwake read to 0xffffc900076a7a00 of 4 bytes by task 17814 on cpu 0: poll_schedule_timeout fs/select.c:240 [inline] do_select+0xe41/0xf40 fs/select.c:603 core_sys_select+0x3b2/0x600 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+0xd0/0x1a0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f write to 0xffffc900076a7a00 of 4 bytes by interrupt on cpu 1: __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+0x63/0xb0 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 __wrmsr arch/x86/include/asm/msr.h:96 [inline] native_write_msr arch/x86/include/asm/msr.h:147 [inline] wrmsr arch/x86/include/asm/msr.h:256 [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+0x80/0x1b0 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+0x47/0x4b bpf_dispatcher_nop_func include/linux/bpf.h:1316 [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:2363 [inline] bpf_trace_run3+0x10c/0x1d0 kernel/trace/bpf_trace.c:2405 __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+0x246/0x2f0 mm/slub.c:4743 kfree_skbmem net/core/skbuff.c:-1 [inline] __kfree_skb+0x109/0x150 net/core/skbuff.c:1177 sk_skb_reason_drop+0xbd/0x270 net/core/skbuff.c:1214 kfree_skb_reason include/linux/skbuff.h:1279 [inline] ip_rcv_core+0x388/0x690 net/ipv4/ip_input.c:550 ip_list_rcv+0x122/0x290 net/ipv4/ip_input.c:652 __netif_receive_skb_list_ptype net/core/dev.c:5930 [inline] __netif_receive_skb_list_core+0x4dc/0x500 net/core/dev.c:5977 __netif_receive_skb_list net/core/dev.c:6029 [inline] netif_receive_skb_list_internal+0x487/0x600 net/core/dev.c:6120 netif_receive_skb_list+0x31/0x200 net/core/dev.c:6172 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+0xdaf/0xfd0 net/bpf/test_run.c:390 bpf_prog_test_run_xdp+0x4f5/0x8f0 net/bpf/test_run.c:1316 bpf_prog_test_run+0x207/0x390 kernel/bpf/syscall.c:4427 __sys_bpf+0x3dc/0x790 kernel/bpf/syscall.c:5852 __do_sys_bpf kernel/bpf/syscall.c:5941 [inline] __se_sys_bpf kernel/bpf/syscall.c:5939 [inline] __x64_sys_bpf+0x41/0x50 kernel/bpf/syscall.c:5939 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+0xd0/0x1a0 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: 1 UID: 0 PID: 17835 Comm: syz.5.5175 Tainted: G W 6.15.0-rc5-syzkaller-00300-g3ce9925823c7 #0 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 ==================================================================