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BUG: KCSAN: data-race in hrtimer_interrupt / print_cpu

read-write to 0xffff888237c1ae14 of 4 bytes by interrupt on cpu 0:
 hrtimer_interrupt+0x72/0x4a0 kernel/time/hrtimer.c:1865
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
 __sysvec_apic_timer_interrupt+0x5c/0x1d0 arch/x86/kernel/apic/apic.c:1055
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0x6e/0x80 arch/x86/kernel/apic/apic.c:1049
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
 __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:95 [inline]
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0x3d/0x60 kernel/locking/spinlock.c:194
 krc_this_cpu_unlock mm/slab_common.c:1451 [inline]
 kvfree_call_rcu+0x2d7/0x330 mm/slab_common.c:1994
 hash_ipmark4_gc_do+0x570/0x5e0 net/netfilter/ipset/ip_set_hash_gen.h:-1
 hash_ipmark4_add+0x20a/0x1050 net/netfilter/ipset/ip_set_hash_gen.h:863
 hash_ipmark4_uadt+0x4db/0x590 net/netfilter/ipset/ip_set_hash_ipmark.c:159
 call_ad+0x1a3/0x550 net/netfilter/ipset/ip_set_core.c:1751
 ip_set_ad+0x5a7/0x670 net/netfilter/ipset/ip_set_core.c:1841
 ip_set_uadd+0x41/0x50 net/netfilter/ipset/ip_set_core.c:1864
 nfnetlink_rcv_msg+0x4ba/0x580 net/netfilter/nfnetlink.c:302
 netlink_rcv_skb+0x12f/0x230 net/netlink/af_netlink.c:2534
 nfnetlink_rcv+0x187/0x1610 net/netfilter/nfnetlink.c:667
 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
 netlink_unicast+0x605/0x6c0 net/netlink/af_netlink.c:1339
 netlink_sendmsg+0x609/0x720 net/netlink/af_netlink.c:1883
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x140/0x180 net/socket.c:727
 ____sys_sendmsg+0x350/0x4e0 net/socket.c:2566
 ___sys_sendmsg net/socket.c:2620 [inline]
 __sys_sendmsg+0x1a0/0x240 net/socket.c:2652
 __do_sys_sendmsg net/socket.c:2657 [inline]
 __se_sys_sendmsg net/socket.c:2655 [inline]
 __x64_sys_sendmsg+0x46/0x50 net/socket.c:2655
 x64_sys_call+0x26f3/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888237c1ae14 of 4 bytes by task 27335 on cpu 1:
 print_cpu+0x354/0x680 kernel/time/timer_list.c:135
 timer_list_show+0x115/0x180 kernel/time/timer_list.c:295
 seq_read_iter+0x661/0x970 fs/seq_file.c:272
 proc_reg_read_iter+0x118/0x190 fs/proc/inode.c:299
 copy_splice_read+0x390/0x5d0 fs/splice.c:363
 do_splice_read fs/splice.c:979 [inline]
 splice_direct_to_actor+0x26c/0x680 fs/splice.c:1083
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0xd9/0x150 fs/splice.c:1227
 do_sendfile+0x40a/0x690 fs/read_write.c:1368
 __do_sys_sendfile64 fs/read_write.c:1429 [inline]
 __se_sys_sendfile64 fs/read_write.c:1415 [inline]
 __x64_sys_sendfile64+0x113/0x160 fs/read_write.c:1415
 x64_sys_call+0xfc3/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1a0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00bdfdff -> 0x00bdfe00

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 27335 Comm: syz.0.7271 Not tainted 6.15.0-rc3-syzkaller-00032-ga79be02bba5c #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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