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BUG: KCSAN: data-race in __blk_queue_split / bio_endio

read to 0xffff88811ee026d4 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
 scsi_end_request+0x6b/0x360 drivers/scsi/scsi_lib.c:576
 scsi_io_completion+0x11d/0xc80 drivers/scsi/scsi_lib.c:960
 scsi_finish_command+0x283/0x380 drivers/scsi/scsi.c:228
 scsi_softirq_done+0x259/0x280 drivers/scsi/scsi_lib.c:1476
 blk_done_softirq+0x1eb/0x250 block/blk-softirq.c:37
 __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]
 do_IRQ+0x81/0x130 arch/x86/kernel/irq.c:263
 ret_from_intr+0x0/0x21
 check_kcov_mode kernel/kcov.c:153 [inline]
 __sanitizer_cov_trace_pc+0x20/0x50 kernel/kcov.c:187
 radix_tree_is_internal_node include/linux/radix-tree.h:45 [inline]
 idr_get_free+0x18e/0x630 lib/radix-tree.c:1523
 idr_alloc_u32+0xf4/0x1c0 lib/idr.c:46
 idr_alloc_cyclic+0xc0/0x1b0 lib/idr.c:125
 __kernfs_new_node+0xd7/0x400 fs/kernfs/dir.c:633
 kernfs_new_node+0x79/0xd0 fs/kernfs/dir.c:689
 __kernfs_create_file+0x5a/0x1c0 fs/kernfs/file.c:1001
 sysfs_add_file_mode_ns+0x16c/0x320 fs/sysfs/file.c:305
 sysfs_merge_group+0xf0/0x1d0 fs/sysfs/group.c:342
 dpm_sysfs_add+0x1de/0x200 drivers/base/power/sysfs.c:656
 device_add+0x6ab/0x1040 drivers/base/core.c:2436
 netdev_register_kobject+0xf5/0x240 net/core/net-sysfs.c:1752
 register_netdevice+0x34e/0xad0 net/core/dev.c:9316
 __ip_tunnel_create+0x214/0x400 net/ipv4/ip_tunnel.c:269
 ip_tunnel_init_net+0x24d/0x3d1 net/ipv4/ip_tunnel.c:1060
 vti_init_net+0x57/0x160 net/ipv4/ip_vti.c:463
 ops_init+0x8c/0x240 net/core/net_namespace.c:137
 setup_net+0x191/0x4b0 net/core/net_namespace.c:335
 copy_net_ns+0x1e7/0x400 net/core/net_namespace.c:476
 create_new_namespaces+0x2e2/0x550 kernel/nsproxy.c:103
 unshare_nsproxy_namespaces+0xb9/0x170 kernel/nsproxy.c:202
 ksys_unshare+0x2dc/0x710 kernel/fork.c:2935
 __do_sys_unshare kernel/fork.c:3003 [inline]
 __se_sys_unshare kernel/fork.c:3001 [inline]
 __x64_sys_unshare+0x28/0x40 kernel/fork.c:3001
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff88811ee026d4 of 2 bytes by task 31847 on cpu 0:
 bio_set_flag include/linux/bio.h:239 [inline]
 __blk_queue_split+0x738/0xc40 block/blk-merge.c:343
 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
 iomap_dio_submit_bio.isra.0+0xfc/0x120 fs/iomap/direct-io.c:70
 iomap_dio_bio_actor+0x40a/0x960 fs/iomap/direct-io.c:306
 iomap_dio_actor+0x87/0x3a0 fs/iomap/direct-io.c:382
 iomap_apply+0x20d/0x6a0 fs/iomap/apply.c:80
 iomap_dio_rw+0x67e/0x9a0 fs/iomap/direct-io.c:498
 ext4_dio_write_iter fs/ext4/file.c:438 [inline]
 ext4_file_write_iter+0xc38/0xd40 fs/ext4/file.c:545
 call_write_iter include/linux/fs.h:1902 [inline]
 new_sync_write+0x388/0x4a0 fs/read_write.c:483
 __vfs_write+0xb1/0xc0 fs/read_write.c:496
 vfs_write fs/read_write.c:558 [inline]
 vfs_write+0x18a/0x390 fs/read_write.c:542
 ksys_write+0xd5/0x1b0 fs/read_write.c:611
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __x64_sys_write+0x4c/0x60 fs/read_write.c:620
 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: 31847 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
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