==================================================================
BUG: KCSAN: data-race in blk_mq_rq_ctx_init / blk_mq_rq_ctx_init

write to 0xffff8881027afd50 of 8 bytes by task 16815 on cpu 1:
 blk_mq_rq_ctx_init+0x3dc/0x4e0 block/blk-mq.c:344
 __blk_mq_alloc_request+0x270/0x290 block/blk-mq.c:399
 blk_mq_submit_bio+0x27f/0xec0 block/blk-mq.c:2199
 __submit_bio_noacct_mq block/blk-core.c:998 [inline]
 submit_bio_noacct+0x6e2/0x7d0 block/blk-core.c:1031
 submit_bio+0x10c/0x190
 iomap_dio_submit_bio fs/iomap/direct-io.c:74 [inline]
 iomap_dio_bio_iter+0x990/0xbc0 fs/iomap/direct-io.c:342
 __iomap_dio_rw+0x8d8/0x1010 fs/iomap/direct-io.c:569
 iomap_dio_rw+0x30/0x70 fs/iomap/direct-io.c:649
 ext4_dio_write_iter fs/ext4/file.c:568 [inline]
 ext4_file_write_iter+0xa59/0x11f0 fs/ext4/file.c:678
 call_write_iter include/linux/fs.h:2163 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x7bc/0x900 fs/read_write.c:594
 ksys_write+0xd9/0x190 fs/read_write.c:647
 __do_sys_write fs/read_write.c:659 [inline]
 __se_sys_write fs/read_write.c:656 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:656
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881027afd50 of 8 bytes by task 16817 on cpu 0:
 blk_mq_rq_ctx_init+0x3ca/0x4e0 block/blk-mq.c:344
 __blk_mq_alloc_request+0x270/0x290 block/blk-mq.c:399
 blk_mq_submit_bio+0x27f/0xec0 block/blk-mq.c:2199
 __submit_bio_noacct_mq block/blk-core.c:998 [inline]
 submit_bio_noacct+0x6e2/0x7d0 block/blk-core.c:1031
 submit_bio+0x10c/0x190
 iomap_dio_submit_bio fs/iomap/direct-io.c:74 [inline]
 iomap_dio_bio_iter+0x990/0xbc0 fs/iomap/direct-io.c:342
 __iomap_dio_rw+0x8d8/0x1010 fs/iomap/direct-io.c:569
 iomap_dio_rw+0x30/0x70 fs/iomap/direct-io.c:649
 ext4_dio_write_iter fs/ext4/file.c:568 [inline]
 ext4_file_write_iter+0xa59/0x11f0 fs/ext4/file.c:678
 call_write_iter include/linux/fs.h:2163 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x7bc/0x900 fs/read_write.c:594
 ksys_write+0xd9/0x190 fs/read_write.c:647
 __do_sys_write fs/read_write.c:659 [inline]
 __se_sys_write fs/read_write.c:656 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:656
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000003a75 -> 0x0000000000003a76

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 16817 Comm: syz-executor.3 Not tainted 5.15.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================