==================================================================
BUG: KCSAN: data-race in do_select / pollwake

write to 0xffffc900001eb9e0 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+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
 __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
 __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]
 kfree_skb include/linux/skbuff.h:1284 [inline]
 napi_free_frags include/linux/netdevice.h:4167 [inline]
 napi_get_frags_check net/core/dev.c:7238 [inline]
 netif_napi_add_weight_locked+0x344/0x550 net/core/dev.c:7276
 netif_napi_add_weight include/linux/netdevice.h:2789 [inline]
 netif_napi_add include/linux/netdevice.h:2806 [inline]
 gro_cells_init+0x146/0x1b0 net/core/gro_cells.c:85
 ip_tunnel_init+0x8d/0x1e0 net/ipv4/ip_tunnel.c:1312
 gre_tap_init+0x206/0x220 net/ipv4/ip_gre.c:1324
 register_netdevice+0x281/0xf00 net/core/dev.c:11032
 __ip_tunnel_create+0x328/0x450 net/ipv4/ip_tunnel.c:268
 ip_tunnel_init_net+0x1ff/0x480 net/ipv4/ip_tunnel.c:1161
 ipgre_tap_init_net+0x35/0x40 net/ipv4/ip_gre.c:1751
 ops_init+0x22a/0x2e0 net/core/net_namespace.c:138
 setup_net+0x124/0x2e0 net/core/net_namespace.c:442
 copy_net_ns+0x55c/0x690 net/core/net_namespace.c:574
 create_new_namespaces+0x20e/0x3d0 kernel/nsproxy.c:110
 copy_namespaces+0x1ad/0x210 kernel/nsproxy.c:175
 copy_process+0xd1b/0x1f90 kernel/fork.c:2172
 kernel_clone+0x16c/0x5b0 kernel/fork.c:2599
 __do_sys_clone kernel/fork.c:2742 [inline]
 __se_sys_clone kernel/fork.c:2726 [inline]
 __x64_sys_clone+0xe6/0x120 kernel/fork.c:2726
 x64_sys_call+0x2c59/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:57
 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

read to 0xffffc900001eb9e0 of 4 bytes by task 11670 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

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 11670 Comm: syz.1.3228 Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================