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BUG: KCSAN: data-race in hrtimer_interrupt / print_cpu

write to 0xffff888237d1ede0 of 8 bytes by interrupt on cpu 1:
 hrtimer_interrupt+0x189/0x7b0 kernel/time/hrtimer.c:1806
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline]
 __sysvec_apic_timer_interrupt+0x52/0x190 arch/x86/kernel/apic/apic.c:1082
 sysvec_apic_timer_interrupt+0x68/0x80 arch/x86/kernel/apic/apic.c:1076
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649
 is_atomic kernel/kcsan/core.c:249 [inline]
 should_watch kernel/kcsan/core.c:277 [inline]
 check_access kernel/kcsan/core.c:752 [inline]
 __tsan_unaligned_write4+0x129/0x180 kernel/kcsan/core.c:1024
 fib6_walk_continue+0x21d/0x430
 fib6_walk+0xc2/0x170 net/ipv6/ip6_fib.c:2166
 fib6_clean_tree net/ipv6/ip6_fib.c:2246 [inline]
 __fib6_clean_all net/ipv6/ip6_fib.c:2262 [inline]
 fib6_flush_trees+0x11c/0x1f0 net/ipv6/ip6_fib.c:2287
 rt_genid_bump_ipv6 include/net/net_namespace.h:523 [inline]
 __ipv6_ifa_notify+0x66c/0x8e0 net/ipv6/addrconf.c:6247
 addrconf_ifdown+0x8ef/0xf10 net/ipv6/addrconf.c:3928
 addrconf_notify+0x310/0x980
 notifier_call_chain kernel/notifier.c:93 [inline]
 raw_notifier_call_chain+0x6b/0x1c0 kernel/notifier.c:461
 call_netdevice_notifiers_info net/core/dev.c:1967 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2005 [inline]
 call_netdevice_notifiers net/core/dev.c:2019 [inline]
 dev_close_many+0x1f0/0x2f0 net/core/dev.c:1560
 unregister_netdevice_many_notify+0x253/0x1080 net/core/dev.c:11013
 unregister_netdevice_many net/core/dev.c:11096 [inline]
 unregister_netdevice_queue+0x1cf/0x200 net/core/dev.c:10976
 unregister_netdevice include/linux/netdevice.h:3158 [inline]
 __tun_detach+0x785/0xa80 drivers/net/tun.c:684
 tun_detach drivers/net/tun.c:700 [inline]
 tun_chr_close+0x5e/0xf0 drivers/net/tun.c:3499
 __fput+0x299/0x630 fs/file_table.c:394
 __fput_sync+0x44/0x50 fs/file_table.c:475
 __do_sys_close fs/open.c:1590 [inline]
 __se_sys_close+0xfa/0x1a0 fs/open.c:1575
 __x64_sys_close+0x1f/0x30 fs/open.c:1575
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888237d1ede0 of 8 bytes by task 22873 on cpu 0:
 print_cpu+0x2fb/0x640 kernel/time/timer_list.c:133
 timer_list_show+0x115/0x180 kernel/time/timer_list.c:291
 seq_read_iter+0x612/0x8f0 fs/seq_file.c:272
 proc_reg_read_iter+0x114/0x180 fs/proc/inode.c:302
 call_read_iter include/linux/fs.h:2014 [inline]
 copy_splice_read+0x26b/0x4b0 fs/splice.c:364
 vfs_splice_read fs/splice.c:993 [inline]
 splice_direct_to_actor+0x28c/0x690 fs/splice.c:1069
 do_splice_direct+0x10d/0x190 fs/splice.c:1194
 do_sendfile+0x3c4/0x980 fs/read_write.c:1254
 __do_sys_sendfile64 fs/read_write.c:1322 [inline]
 __se_sys_sendfile64 fs/read_write.c:1308 [inline]
 __x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x000002583972843f -> 0x0000025839cb4380

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 22873 Comm: syz-executor.2 Not tainted 6.7.0-rc4-syzkaller-00111-g5e3f5b81de80 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
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