================================================================== BUG: KCSAN: data-race in block_uevent / inc_diskseq write to 0xffff888101f05220 of 8 bytes by task 3101 on cpu 0: inc_diskseq+0x2c/0x40 block/genhd.c:1472 disk_force_media_change+0x9f/0xf0 block/disk-events.c:297 __loop_clr_fd+0x270/0x3f0 drivers/block/loop.c:1193 loop_clr_fd drivers/block/loop.c:1276 [inline] lo_ioctl+0xea6/0x1330 drivers/block/loop.c:1578 blkdev_ioctl+0x35f/0x450 block/ioctl.c:676 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xd3/0x150 fs/ioctl.c:893 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:893 x64_sys_call+0x1581/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffff888101f05220 of 8 bytes by task 3091 on cpu 1: block_uevent+0x31/0x50 block/genhd.c:1206 dev_uevent+0x2f3/0x380 drivers/base/core.c:2687 uevent_show+0x11e/0x210 drivers/base/core.c:2745 dev_attr_show+0x3a/0xa0 drivers/base/core.c:2437 sysfs_kf_seq_show+0x17c/0x250 fs/sysfs/file.c:59 kernfs_seq_show+0x7c/0x90 fs/kernfs/file.c:205 seq_read_iter+0x2d7/0x940 fs/seq_file.c:230 kernfs_fop_read_iter+0xc6/0x310 fs/kernfs/file.c:279 new_sync_read fs/read_write.c:395 [inline] vfs_read+0x5e6/0x6e0 fs/read_write.c:476 ksys_read+0xeb/0x1b0 fs/read_write.c:619 __do_sys_read fs/read_write.c:629 [inline] __se_sys_read fs/read_write.c:627 [inline] __x64_sys_read+0x42/0x50 fs/read_write.c:627 x64_sys_call+0x27e5/0x2d70 arch/x86/include/generated/asm/syscalls_64.h:1 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x0000000000000045 -> 0x0000000000000048 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 3091 Comm: udevd Not tainted 6.10.0-rc4-syzkaller-00035-g3d54351c64e8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 ==================================================================