syzbot

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BUG: KCSAN: data-race in hrtimer_interrupt / print_tickdevice

write to 0xffff888237c1bf18 of 8 bytes by interrupt on cpu 0:
 hrtimer_interrupt+0x7d/0x7b0 kernel/time/hrtimer.c:1793
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1098 [inline]
 __sysvec_apic_timer_interrupt+0x73/0x210 arch/x86/kernel/apic/apic.c:1115
 sysvec_apic_timer_interrupt+0x68/0x80 arch/x86/kernel/apic/apic.c:1109
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
 variable__ffs arch/x86/include/asm/bitops.h:252 [inline]
 _find_next_zero_bit+0xc5/0xf0 lib/find_bit.c:198
 find_next_zero_bit include/linux/find.h:186 [inline]
 find_next_fd fs/file.c:488 [inline]
 alloc_fd+0xc2/0x370 fs/file.c:514
 __get_unused_fd_flags fs/file.c:559 [inline]
 get_unused_fd_flags+0x44/0x50 fs/file.c:564
 do_sys_openat2+0x89/0x110 fs/open.c:1420
 do_sys_open fs/open.c:1437 [inline]
 __do_sys_openat fs/open.c:1453 [inline]
 __se_sys_openat fs/open.c:1448 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1448
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888237c1bf18 of 8 bytes by task 30319 on cpu 1:
 print_tickdevice+0x144/0x340 kernel/time/timer_list.c:204
 timer_list_show+0x79/0x180 kernel/time/timer_list.c:296
 seq_read_iter+0x612/0x8f0 fs/seq_file.c:272
 proc_reg_read_iter+0x114/0x180 fs/proc/inode.c:305
 call_read_iter include/linux/fs.h:1979 [inline]
 copy_splice_read+0x26b/0x4b0 fs/splice.c:365
 vfs_splice_read fs/splice.c:994 [inline]
 splice_direct_to_actor+0x28c/0x690 fs/splice.c:1070
 do_splice_direct+0x10d/0x190 fs/splice.c:1195
 do_sendfile+0x3b6/0x9a0 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:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x000001c6778fe414 -> 0x7fffffffffffffff

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 30319 Comm: syz-executor.1 Not tainted 6.5.0-syzkaller-01810-gf97e18a3f2fb #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
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