==================================================================
BUG: KCSAN: data-race in enqueue_timer / wbt_wait

write to 0xffff88812a92ab18 of 8 bytes by interrupt on cpu 1:
 hlist_add_head include/linux/list.h:787 [inline]
 enqueue_timer+0x6c/0x210 kernel/time/timer.c:540
 __internal_add_timer+0x4f/0x60 kernel/time/timer.c:553
 internal_add_timer kernel/time/timer.c:595 [inline]
 __mod_timer kernel/time/timer.c:1053 [inline]
 mod_timer+0x303/0x7a0 kernel/time/timer.c:1100
 garp_join_timer_arm+0x65/0x80 net/802/garp.c:398
 garp_join_timer+0x7c/0x90 net/802/garp.c:411
 call_timer_fn+0x5f/0x2f0 kernel/time/timer.c:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers kernel/time/timer.c:1773 [inline]
 __run_timers kernel/time/timer.c:1740 [inline]
 run_timer_softirq+0xc0c/0xcd0 kernel/time/timer.c:1786
 __do_softirq+0x115/0x33f kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0xbb/0xe0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0xe6/0x280 arch/x86/kernel/apic/apic.c:1137
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline]
 kcsan_setup_watchpoint+0x1d4/0x460 kernel/kcsan/core.c:429
 check_access kernel/kcsan/core.c:459 [inline]
 __tsan_read4+0xc6/0x100 kernel/kcsan/core.c:588
 __tlb_remove_page_size+0x45/0x1d0 mm/mmu_gather.c:81
 __tlb_remove_page include/asm-generic/tlb.h:414 [inline]
 zap_pte_range mm/memory.c:1083 [inline]
 zap_pmd_range mm/memory.c:1184 [inline]
 zap_pud_range mm/memory.c:1213 [inline]
 zap_p4d_range mm/memory.c:1234 [inline]
 unmap_page_range+0xb8e/0x1940 mm/memory.c:1255
 unmap_single_vma+0x144/0x200 mm/memory.c:1300
 unmap_vmas+0xda/0x1a0 mm/memory.c:1332
 exit_mmap+0x13e/0x300 mm/mmap.c:3140
 __mmput kernel/fork.c:1082 [inline]
 mmput+0xea/0x280 kernel/fork.c:1103
 exit_mm kernel/exit.c:485 [inline]
 do_exit+0x4ac/0x18c0 kernel/exit.c:784
 do_group_exit+0xb4/0x1c0 kernel/exit.c:895
 get_signal+0x2a2/0x1320 kernel/signal.c:2734
 do_signal+0x2f/0x6c0 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x250/0x2c0 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x384/0x3a0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88812a92ab18 of 8 bytes by task 13462 on cpu 0:
 blk_stat_is_active block/blk-stat.h:131 [inline]
 wbt_wait+0x177/0x250 block/blk-wbt.c:593
 __rq_qos_throttle+0x47/0x70 block/blk-rq-qos.c:72
 rq_qos_throttle block/blk-rq-qos.h:182 [inline]
 blk_mq_make_request+0x29c/0xf60 block/blk-mq.c:1932
 generic_make_request block/blk-core.c:1066 [inline]
 generic_make_request+0x196/0x700 block/blk-core.c:1008
 submit_bio+0x96/0x3c0 block/blk-core.c:1192
 submit_bh_wbc+0x40f/0x460 fs/buffer.c:3135
 submit_bh fs/buffer.c:3141 [inline]
 write_dirty_buffer fs/buffer.c:3209 [inline]
 write_dirty_buffer+0x83/0x100 fs/buffer.c:3200
 fat_sync_bhs+0x59/0x14b fs/fat/misc.c:349
 fat_alloc_clusters+0xae6/0xc40 fs/fat/fatent.c:539
 fat_add_cluster+0x3d/0xd0 fs/fat/inode.c:107
 __fat_get_block fs/fat/inode.c:154 [inline]
 fat_get_block+0x3ae/0x4e0 fs/fat/inode.c:189
 __block_write_begin_int+0x2ea/0xf10 fs/buffer.c:2008
 __block_write_begin fs/buffer.c:2058 [inline]
 block_write_begin+0x77/0x160 fs/buffer.c:2117
 cont_write_begin+0x3d6/0x670 fs/buffer.c:2466
 fat_write_begin+0x72/0xc0 fs/fat/inode.c:235
 pagecache_write_begin+0x6b/0x90 mm/filemap.c:3128
 cont_expand_zero fs/buffer.c:2393 [inline]
 cont_write_begin+0x17a/0x670 fs/buffer.c:2456
 fat_write_begin+0x72/0xc0 fs/fat/inode.c:235
 pagecache_write_begin+0x6b/0x90 mm/filemap.c:3128
 generic_cont_expand_simple+0xb0/0x120 fs/buffer.c:2357
 fat_cont_expand+0x4e/0x1c0 fs/fat/file.c:222
 fat_setattr+0x75d/0x840 fs/fat/file.c:501
 notify_change+0x7e1/0xaa0 fs/attr.c:337
 do_truncate+0xfb/0x180 fs/open.c:64
 do_sys_ftruncate+0x30f/0x340 fs/open.c:195
 __do_sys_ftruncate fs/open.c:205 [inline]
 __se_sys_ftruncate fs/open.c:203 [inline]
 __x64_sys_ftruncate+0x3f/0x50 fs/open.c:203
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 13462 Comm: syz-executor.5 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================