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BUG: KCSAN: data-race in relay_switch_subbuf / relay_switch_subbuf

write to 0xffff88813562d038 of 8 bytes by interrupt on cpu 1:
 relay_switch_subbuf+0x3b5/0x3c0 kernel/relay.c:711
 relay_reserve include/linux/relay.h:248 [inline]
 __blk_add_trace+0x66f/0x740 kernel/trace/blktrace.c:275
 blk_add_trace_rq kernel/trace/blktrace.c:846 [inline]
 blk_add_trace_rq_complete+0x102/0x110 kernel/trace/blktrace.c:879
 trace_block_rq_complete include/trace/events/block.h:115 [inline]
 blk_update_request+0x8a9/0x8f0 block/blk-mq.c:784
 scsi_end_request+0x4b/0x460 drivers/scsi/scsi_lib.c:543
 scsi_io_completion+0xdf/0x1220 drivers/scsi/scsi_lib.c:980
 scsi_finish_command+0x1d0/0x1e0 drivers/scsi/scsi.c:198
 scsi_complete+0x1a5/0x1e0 drivers/scsi/scsi_lib.c:1482
 blk_complete_reqs block/blk-mq.c:1003 [inline]
 blk_done_softirq+0x92/0xc0 block/blk-mq.c:1008
 __do_softirq+0x158/0x2de kernel/softirq.c:558
 __irq_exit_rcu kernel/softirq.c:637 [inline]
 irq_exit_rcu+0x37/0x70 kernel/softirq.c:649
 common_interrupt+0x9f/0xc0 arch/x86/kernel/irq.c:240
 asm_common_interrupt+0x1e/0x40
 should_watch kernel/kcsan/core.c:278 [inline]
 check_access kernel/kcsan/core.c:741 [inline]
 __tsan_read8+0x154/0x180 kernel/kcsan/core.c:1014
 folio_test_anon include/linux/page-flags.h:582 [inline]
 PageAnon include/linux/page-flags.h:587 [inline]
 mm_counter include/linux/mm.h:2043 [inline]
 copy_present_pte mm/memory.c:960 [inline]
 copy_pte_range+0x6a7/0x1730 mm/memory.c:1074
 copy_pmd_range mm/memory.c:1160 [inline]
 copy_pud_range mm/memory.c:1197 [inline]
 copy_p4d_range mm/memory.c:1221 [inline]
 copy_page_range+0x5ea/0x8f0 mm/memory.c:1294
 dup_mmap+0x6eb/0xa60 kernel/fork.c:612
 dup_mm+0x7c/0x210 kernel/fork.c:1451
 copy_mm kernel/fork.c:1503 [inline]
 copy_process+0x13d7/0x2f40 kernel/fork.c:2164
 kernel_clone+0x15c/0x6a0 kernel/fork.c:2565
 __do_sys_clone kernel/fork.c:2682 [inline]
 __se_sys_clone kernel/fork.c:2666 [inline]
 __x64_sys_clone+0xc6/0xf0 kernel/fork.c:2666
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

write to 0xffff88813562d038 of 8 bytes by task 13000 on cpu 0:
 relay_switch_subbuf+0x3b5/0x3c0 kernel/relay.c:711
 relay_reserve include/linux/relay.h:248 [inline]
 __blk_add_trace+0x66f/0x740 kernel/trace/blktrace.c:275
 blk_add_trace_bio kernel/trace/blktrace.c:906 [inline]
 blk_add_trace_bio_queue+0xb1/0xc0 kernel/trace/blktrace.c:938
 trace_block_bio_queue include/trace/events/block.h:332 [inline]
 submit_bio_checks+0x84e/0x890 block/blk-core.c:770
 __submit_bio+0x41/0x350 block/blk-core.c:800
 __submit_bio_noacct_mq block/blk-core.c:879 [inline]
 submit_bio_noacct+0x418/0x4e0 block/blk-core.c:905
 submit_bio+0x10c/0x180
 iomap_dio_submit_bio fs/iomap/direct-io.c:66 [inline]
 iomap_dio_bio_iter+0x9ed/0xc70 fs/iomap/direct-io.c:351
 __iomap_dio_rw+0x8d6/0x10a0 fs/iomap/direct-io.c:590
 iomap_dio_rw+0x38/0x80 fs/iomap/direct-io.c:680
 ext4_dio_read_iter fs/ext4/file.c:77 [inline]
 ext4_file_read_iter+0x190/0x1f0 fs/ext4/file.c:128
 call_read_iter include/linux/fs.h:2068 [inline]
 generic_file_splice_read+0x24f/0x330 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+0x106/0x190 fs/splice.c:979
 do_sendfile+0x675/0xc40 fs/read_write.c:1245
 __do_sys_sendfile64 fs/read_write.c:1310 [inline]
 __se_sys_sendfile64 fs/read_write.c:1296 [inline]
 __x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1296
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000000040 -> 0x0000000000000030

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 13000 Comm: syz-executor.1 Not tainted 5.17.0-rc8-syzkaller-00072-g97e9c8eb4bb1-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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