================================================================== BUG: KCSAN: data-race in block_uevent / inc_diskseq write to 0xffff88810144fe20 of 8 bytes by task 12945 on cpu 1: inc_diskseq+0x2c/0x40 block/genhd.c:1472 disk_force_media_change+0x9f/0xf0 block/disk-events.c:297 loop_configure+0x626/0xa30 drivers/block/loop.c:1085 lo_ioctl+0x5f6/0x11c0 blkdev_ioctl+0x359/0x450 block/ioctl.c:693 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xcd/0x140 fs/ioctl.c:893 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:893 x64_sys_call+0x15cc/0x2d60 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 0xffff88810144fe20 of 8 bytes by task 2967 on cpu 0: block_uevent+0x31/0x50 block/genhd.c:1206 dev_uevent+0x2fd/0x380 drivers/base/core.c:2686 uevent_show+0x10c/0x1f0 drivers/base/core.c:2742 dev_attr_show+0x3a/0xa0 drivers/base/core.c:2431 sysfs_kf_seq_show+0x17c/0x250 fs/sysfs/file.c:59 kernfs_seq_show+0x7c/0x90 fs/kernfs/file.c:205 seq_read_iter+0x2d1/0x930 fs/seq_file.c:230 kernfs_fop_read_iter+0xc0/0x310 fs/kernfs/file.c:279 new_sync_read fs/read_write.c:488 [inline] vfs_read+0x5f6/0x720 fs/read_write.c:569 ksys_read+0xeb/0x1b0 fs/read_write.c:712 __do_sys_read fs/read_write.c:722 [inline] __se_sys_read fs/read_write.c:720 [inline] __x64_sys_read+0x42/0x50 fs/read_write.c:720 x64_sys_call+0x27d3/0x2d60 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: 0x0000000000000293 -> 0x0000000000000295 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 2967 Comm: udevd Not tainted 6.12.0-rc2-syzkaller-00074-gd3d1556696c1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 ================================================================== loop4: p1 p2 p3