================================================================== BUG: KCSAN: data-race in block_uevent / inc_diskseq write to 0xffff888102416a18 of 8 bytes by task 4822 on cpu 1: inc_diskseq+0x2d/0x40 block/genhd.c:1577 disk_force_media_change+0x9e/0xe0 block/disk-events.c:297 __loop_clr_fd drivers/block/loop.c:1136 [inline] lo_release+0x2cb/0x400 drivers/block/loop.c:1716 bdev_release+0x373/0x3d0 block/bdev.c:-1 blkdev_release+0x15/0x20 block/fops.c:684 __fput+0x29b/0x650 fs/file_table.c:465 fput_close_sync+0x6e/0x120 fs/file_table.c:570 __do_sys_close fs/open.c:1589 [inline] __se_sys_close fs/open.c:1574 [inline] __x64_sys_close+0x56/0xf0 fs/open.c:1574 x64_sys_call+0x2747/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:4 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff888102416a18 of 8 bytes by task 3007 on cpu 0: block_uevent+0x31/0x50 block/genhd.c:1315 dev_uevent+0x34c/0x3d0 drivers/base/core.c:2703 uevent_show+0x11a/0x200 drivers/base/core.c:2759 dev_attr_show+0x3f/0xa0 drivers/base/core.c:2424 sysfs_kf_seq_show+0x1a0/0x280 fs/sysfs/file.c:65 kernfs_seq_show+0x82/0xa0 fs/kernfs/file.c:205 seq_read_iter+0x316/0x940 fs/seq_file.c:230 kernfs_fop_read_iter+0xc4/0x300 fs/kernfs/file.c:279 new_sync_read fs/read_write.c:491 [inline] vfs_read+0x5ca/0x6f0 fs/read_write.c:572 ksys_read+0xda/0x1a0 fs/read_write.c:715 __do_sys_read fs/read_write.c:724 [inline] __se_sys_read fs/read_write.c:722 [inline] __x64_sys_read+0x40/0x50 fs/read_write.c:722 x64_sys_call+0x2d77/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:1 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x00000000000000b7 -> 0x00000000000000b8 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 3007 Comm: udevd Not tainted 6.15.0-syzkaller-12426-ge271ed52b344 #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 ==================================================================