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BUG: KCSAN: data-race in blk_stat_add / blk_stat_timer_fn

read to 0xffffe8ffffd35f90 of 4 bytes by interrupt on cpu 0:
 blk_rq_stat_sum block/blk-stat.c:31 [inline]
 blk_stat_timer_fn+0x1bf/0x410 block/blk-stat.c:94
 call_timer_fn+0x2e/0x240 kernel/time/timer.c:1410
 expire_timers+0x116/0x260 kernel/time/timer.c:1455
 __run_timers+0x328/0x3c0 kernel/time/timer.c:1747
 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1760
 __do_softirq+0x12c/0x2b1 kernel/softirq.c:298
 asm_call_irq_on_stack+0xf/0x20
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
 do_softirq_own_stack+0x32/0x40 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:393 [inline]
 __irq_exit_rcu+0xb2/0xc0 kernel/softirq.c:423
 sysvec_apic_timer_interrupt+0x74/0x90 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631
 native_restore_fl arch/x86/include/asm/irqflags.h:41 [inline]
 arch_local_irq_restore arch/x86/include/asm/irqflags.h:84 [inline]
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
 _raw_spin_unlock_irqrestore+0x32/0x50 kernel/locking/spinlock.c:191
 unlock_hrtimer_base kernel/time/hrtimer.c:897 [inline]
 hrtimer_start_range_ns+0x226/0x250 kernel/time/hrtimer.c:1135
 hrtimer_start_expires include/linux/hrtimer.h:436 [inline]
 hrtimer_sleeper_start_expires kernel/time/hrtimer.c:1799 [inline]
 do_nanosleep+0xd2/0x390 kernel/time/hrtimer.c:1875
 hrtimer_nanosleep kernel/time/hrtimer.c:1931 [inline]
 __do_sys_nanosleep kernel/time/hrtimer.c:1965 [inline]
 __se_sys_nanosleep+0x20b/0x2a0 kernel/time/hrtimer.c:1952
 __x64_sys_nanosleep+0x2d/0x40 kernel/time/hrtimer.c:1952
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read-write to 0xffffe8ffffd35f90 of 4 bytes by interrupt on cpu 1:
 blk_rq_stat_add block/blk-stat.c:48 [inline]
 blk_stat_add+0x189/0x230 block/blk-stat.c:74
 __blk_mq_end_request+0x142/0x230 block/blk-mq.c:544
 scsi_end_request+0x2ac/0x470 drivers/scsi/scsi_lib.c:603
 scsi_io_completion+0x105/0xfb0 drivers/scsi/scsi_lib.c:965
 scsi_finish_command+0x26c/0x2b0 drivers/scsi/scsi.c:214
 scsi_softirq_done+0xdf/0x440 drivers/scsi/scsi_lib.c:1443
 blk_done_softirq+0x145/0x190 block/blk-mq.c:586
 __do_softirq+0x12c/0x2b1 kernel/softirq.c:298
 asm_call_irq_on_stack+0xf/0x20
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
 do_softirq_own_stack+0x32/0x40 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:393 [inline]
 __irq_exit_rcu+0xb2/0xc0 kernel/softirq.c:423
 sysvec_apic_timer_interrupt+0x74/0x90 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631
 native_restore_fl arch/x86/include/asm/irqflags.h:41 [inline]
 arch_local_irq_restore arch/x86/include/asm/irqflags.h:84 [inline]
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
 _raw_spin_unlock_irqrestore+0x32/0x50 kernel/locking/spinlock.c:191
 spin_unlock_irqrestore include/linux/spinlock.h:409 [inline]
 __test_set_page_writeback+0x3ca/0x5b0 mm/page-writeback.c:2809
 ext4_bio_write_page+0xef/0xda0 fs/ext4/page-io.c:453
 mpage_submit_page fs/ext4/inode.c:2090 [inline]
 mpage_map_and_submit_buffers fs/ext4/inode.c:2338 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2477 [inline]
 ext4_writepages+0xe8b/0x1e10 fs/ext4/inode.c:2790
 do_writepages+0x7b/0x150 mm/page-writeback.c:2352
 __filemap_fdatawrite_range+0x19d/0x1d0 mm/filemap.c:422
 file_write_and_wait_range+0x9f/0x120 mm/filemap.c:761
 ext4_sync_file+0xf4/0x6a0 fs/ext4/fsync.c:151
 vfs_fsync_range+0x107/0x120 fs/sync.c:200
 generic_write_sync include/linux/fs.h:2723 [inline]
 ext4_buffered_write_iter+0x384/0x3d0 fs/ext4/file.c:278
 ext4_file_write_iter+0x45e/0x1090 fs/ext4/file.c:503
 call_write_iter include/linux/fs.h:1887 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x617/0x690 fs/read_write.c:605
 ksys_write+0xce/0x180 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:667
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3199 Comm: syz-executor.3 Not tainted 5.10.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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