================================================================== BUG: KCSAN: data-race in __bio_queue_enter / blk_mq_update_tag_set_shared read-write to 0xffff88810267ea34 of 4 bytes by task 6059 on cpu 1: __blk_mq_unfreeze_queue block/blk-mq.c:218 [inline] blk_mq_unfreeze_queue_nomemrestore block/blk-mq.c:232 [inline] blk_mq_unfreeze_queue include/linux/blk-mq.h:962 [inline] blk_mq_update_tag_set_shared+0xa9/0x170 block/blk-mq.c:4310 blk_mq_add_queue_tag_set block/blk-mq.c:4341 [inline] blk_mq_init_allocated_queue+0x75d/0x910 block/blk-mq.c:4661 blk_mq_alloc_queue+0xd8/0x130 block/blk-mq.c:4424 scsi_alloc_sdev+0x3e3/0x5f0 drivers/scsi/scsi_scan.c:339 scsi_probe_and_add_lun+0xa3/0x2030 drivers/scsi/scsi_scan.c:1228 __scsi_scan_target+0x143/0x7f0 drivers/scsi/scsi_scan.c:1805 scsi_scan_channel drivers/scsi/scsi_scan.c:1895 [inline] scsi_scan_host_selected+0x2ba/0x3f0 drivers/scsi/scsi_scan.c:1924 scsi_scan drivers/scsi/scsi_sysfs.c:151 [inline] store_scan+0x371/0x3c0 drivers/scsi/scsi_sysfs.c:191 dev_attr_store+0x4a/0x70 drivers/base/core.c:2509 sysfs_kf_write+0xfe/0x120 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x1d2/0x2e0 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x57f/0x9a0 fs/read_write.c:687 ksys_write+0xdc/0x1a0 fs/read_write.c:739 __do_sys_write fs/read_write.c:750 [inline] __se_sys_write fs/read_write.c:747 [inline] __x64_sys_write+0x40/0x50 fs/read_write.c:747 x64_sys_call+0x154e/0x2550 arch/x86/include/generated/asm/syscalls_64.h:2 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff88810267ea34 of 4 bytes by task 3438 on cpu 0: __bio_queue_enter+0x1e5/0x580 block/blk-core.c:397 bio_queue_enter block/blk.h:99 [inline] blk_mq_submit_bio+0x18a/0x1120 block/blk-mq.c:3127 __submit_bio+0x54/0x3d0 block/blk-core.c:673 __submit_bio_noacct_mq block/blk-core.c:756 [inline] submit_bio_noacct_nocheck+0x153/0x620 block/blk-core.c:790 submit_bio_noacct+0x760/0x980 block/blk-core.c:925 submit_bio+0x2a4/0x2c0 block/blk-core.c:966 blk_crypto_submit_bio include/linux/blk-crypto.h:212 [inline] ext4_io_submit fs/ext4/page-io.c:396 [inline] io_submit_add_bh fs/ext4/page-io.c:452 [inline] ext4_bio_write_folio+0x702/0xa10 fs/ext4/page-io.c:547 mpage_submit_folio fs/ext4/inode.c:2094 [inline] mpage_process_page_bufs+0x484/0x5e0 fs/ext4/inode.c:2201 mpage_prepare_extent_to_map+0x83e/0xca0 fs/ext4/inode.c:2743 ext4_do_writepages+0x70f/0x2870 fs/ext4/inode.c:2884 ext4_writepages+0x191/0x300 fs/ext4/inode.c:3032 do_writepages+0x1b9/0x300 mm/page-writeback.c:2560 __writeback_single_inode+0x7b/0x790 fs/fs-writeback.c:1788 writeback_sb_inodes+0x4d9/0xaa0 fs/fs-writeback.c:2099 __writeback_inodes_wb+0x8a/0x180 fs/fs-writeback.c:2175 wb_writeback+0x21e/0x510 fs/fs-writeback.c:2286 wb_check_old_data_flush fs/fs-writeback.c:2390 [inline] wb_do_writeback fs/fs-writeback.c:2469 [inline] wb_workfn+0x740/0xa50 fs/fs-writeback.c:2497 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0x56a/0xa50 kernel/workqueue.c:3479 worker_thread+0x569/0x750 kernel/workqueue.c:3560 kthread+0x223/0x270 kernel/kthread.c:436 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 value changed: 0x00000001 -> 0x00000000 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 3438 Comm: kworker/u8:7 Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: writeback wb_workfn (flush-8:0) ==================================================================