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BUG: KCSAN: data-race in __hrtimer_rearm_deferred / print_cpu

write to 0xffff888237c1b8e8 of 8 bytes by task 12169 on cpu 0:
 hrtimer_rearm kernel/time/hrtimer.c:2028 [inline]
 __hrtimer_rearm_deferred+0x537/0x670 kernel/time/hrtimer.c:2059
 hrtimer_rearm_deferred_tif include/linux/hrtimer_rearm.h:53 [inline]
 hrtimer_rearm_deferred include/linux/hrtimer_rearm.h:62 [inline]
 irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:513 [inline]
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:550 [inline]
 irqentry_exit+0x527/0x5b0 kernel/entry/common.c:164
 sysvec_apic_timer_interrupt+0x44/0x80 arch/x86/kernel/apic/apic.c:1061
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_slow+0x58/0x180 net/netfilter/core.c:619
 nf_hook include/linux/netfilter.h:273 [inline]
 NF_HOOK include/linux/netfilter.h:316 [inline]
 ip6_input+0x118/0x160 net/ipv6/ip6_input.c:540
 dst_input include/net/dst.h:480 [inline]
 ip6_sublist_rcv_finish net/ipv6/ip6_input.c:128 [inline]
 ip6_list_rcv_finish net/ipv6/ip6_input.c:185 [inline]
 ip6_sublist_rcv+0x8d6/0xa00 net/ipv6/ip6_input.c:361
 ipv6_list_rcv+0x267/0x2a0 net/ipv6/ip6_input.c:395
 __netif_receive_skb_list_ptype net/core/dev.c:6252 [inline]
 __netif_receive_skb_list_core+0x3b0/0x500 net/core/dev.c:6299
 __netif_receive_skb_list net/core/dev.c:6351 [inline]
 netif_receive_skb_list_internal+0x47d/0x5f0 net/core/dev.c:6442
 netif_receive_skb_list+0x33/0x1c0 net/core/dev.c:6494
 xdp_recv_frames net/bpf/test_run.c:269 [inline]
 xdp_test_run_batch net/bpf/test_run.c:350 [inline]
 bpf_test_run_xdp_live+0x104c/0x1360 net/bpf/test_run.c:379
 bpf_prog_test_run_xdp+0x57b/0xa10 net/bpf/test_run.c:1430
 bpf_prog_test_run+0x204/0x340 kernel/bpf/syscall.c:4742
 __sys_bpf+0x52e/0x7e0 kernel/bpf/syscall.c:6266
 __do_sys_bpf kernel/bpf/syscall.c:6361 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6359 [inline]
 __x64_sys_bpf+0x41/0x50 kernel/bpf/syscall.c:6359
 x64_sys_call+0x10cb/0x3020 arch/x86/include/generated/asm/syscalls_64.h:322
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c1b8e8 of 8 bytes by task 12170 on cpu 1:
 print_cpu+0x2fb/0x670 kernel/time/timer_list.c:129
 timer_list_show+0x107/0x170 kernel/time/timer_list.c:291
 seq_read_iter+0x636/0x940 fs/seq_file.c:273
 proc_reg_read_iter+0x110/0x180 fs/proc/inode.c:299
 copy_splice_read+0x471/0x6c0 fs/splice.c:362
 do_splice_read fs/splice.c:980 [inline]
 splice_direct_to_actor+0x26e/0x670 fs/splice.c:1084
 do_splice_direct_actor fs/splice.c:1202 [inline]
 do_splice_direct+0x119/0x1a0 fs/splice.c:1228
 do_sendfile+0x382/0x650 fs/read_write.c:1372
 __do_sys_sendfile64 fs/read_write.c:1433 [inline]
 __se_sys_sendfile64 fs/read_write.c:1419 [inline]
 __x64_sys_sendfile64+0x105/0x150 fs/read_write.c:1419
 x64_sys_call+0x2dc4/0x3020 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x7fffffffffffffff -> 0x000000402d5241f2

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 12170 Comm: syz.4.2929 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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