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BUG: KCSAN: data-race in hrtimer_interrupt / print_cpu

write to 0xffff888237c397e0 of 8 bytes by interrupt on cpu 0:
 hrtimer_interrupt+0x1fb/0xaf0 kernel/time/hrtimer.c:1655
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x6f/0x1c0 arch/x86/kernel/apic/apic.c:1106
 sysvec_apic_timer_interrupt+0x64/0x80 arch/x86/kernel/apic/apic.c:1100
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
 arch_atomic_inc arch/x86/include/asm/atomic.h:95 [inline]
 atomic_inc include/asm-generic/atomic-instrumented.h:182 [inline]
 get_bh include/linux/buffer_head.h:279 [inline]
 __find_get_block_slow fs/buffer.c:216 [inline]
 __find_get_block+0x296/0x900 fs/buffer.c:1308
 sb_find_get_block include/linux/buffer_head.h:340 [inline]
 recently_deleted fs/ext4/ialloc.c:687 [inline]
 find_inode_bit+0x181/0x330 fs/ext4/ialloc.c:729
 __ext4_new_inode+0xc7a/0x2f70 fs/ext4/ialloc.c:1064
 ext4_mkdir+0x28a/0x760 fs/ext4/namei.c:2921
 vfs_mkdir+0x2a4/0x370 fs/namei.c:3823
 do_mkdirat+0x11d/0x200 fs/namei.c:3848
 __do_sys_mkdir fs/namei.c:3866 [inline]
 __se_sys_mkdir fs/namei.c:3864 [inline]
 __x64_sys_mkdir+0x32/0x40 fs/namei.c:3864
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888237c397e0 of 8 bytes by task 14500 on cpu 1:
 print_cpu+0x32e/0x690 kernel/time/timer_list.c:133
 timer_list_show+0x114/0x180 kernel/time/timer_list.c:291
 seq_read_iter+0x2e1/0x930 fs/seq_file.c:230
 proc_reg_read_iter+0xfc/0x170 fs/proc/inode.c:300
 call_read_iter include/linux/fs.h:2108 [inline]
 generic_file_splice_read+0x22a/0x310 fs/splice.c:311
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:870
 do_splice_direct+0xf5/0x170 fs/splice.c:979
 do_sendfile+0x773/0xda0 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1325 [inline]
 __se_sys_sendfile64 fs/read_write.c:1311 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000009fa902b861 -> 0x0000009fa903c7ae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 14500 Comm: syz-executor.5 Not tainted 5.14.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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