==================================================================
BUG: KCSAN: data-race in bio_chain / bio_endio

read to 0xffff888129cf9254 of 2 bytes by interrupt on cpu 1:
 bio_remaining_done block/bio.c:1760 [inline]
 bio_endio+0x3e/0x400 block/bio.c:1790
 req_bio_endio block/blk-core.c:245 [inline]
 blk_update_request+0x427/0x7b0 block/blk-core.c:1464
 blk_mq_end_request+0x3f/0x2b0 block/blk-mq.c:546
 end_cmd drivers/block/null_blk_main.c:648 [inline]
 end_cmd+0xa9/0x1a0 drivers/block/null_blk_main.c:642
 null_complete_rq+0x22/0x30 drivers/block/null_blk_main.c:675
 blk_done_softirq+0x1eb/0x250 block/blk-softirq.c:37
 __do_softirq+0x115/0x33f kernel/softirq.c:292
 run_ksoftirqd+0x46/0x60 kernel/softirq.c:603
 smpboot_thread_fn+0x37d/0x4a0 kernel/smpboot.c:165
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

write to 0xffff888129cf9254 of 2 bytes by task 16211 on cpu 0:
 bio_set_flag include/linux/bio.h:239 [inline]
 bio_inc_remaining include/linux/bio.h:689 [inline]
 bio_chain+0x86/0xb0 block/bio.c:336
 __blk_queue_split+0x757/0xc40 block/blk-merge.c:345
 blk_mq_make_request+0x104/0xf60 block/blk-mq.c:1920
 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
 blk_next_bio+0x53/0x70 block/blk-lib.c:19
 __blkdev_issue_zero_pages+0x104/0x300 block/blk-lib.c:284
 blkdev_issue_zeroout+0x337/0x370 block/blk-lib.c:378
 blk_ioctl_zeroout block/ioctl.c:237 [inline]
 blkdev_ioctl+0xe33/0x1260 block/ioctl.c:504
 block_ioctl+0x95/0xc0 fs/block_dev.c:1983
 vfs_ioctl fs/ioctl.c:47 [inline]
 file_ioctl fs/ioctl.c:545 [inline]
 do_vfs_ioctl+0x84f/0xcf0 fs/ioctl.c:732
 ksys_ioctl+0xbd/0xe0 fs/ioctl.c:749
 __do_sys_ioctl fs/ioctl.c:756 [inline]
 __se_sys_ioctl fs/ioctl.c:754 [inline]
 __x64_sys_ioctl+0x4c/0x60 fs/ioctl.c:754
 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: 16211 Comm: syz-executor.4 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================