KCSAN: data-race in __loop_clr_fd / blkdev_common

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in __loop_clr_fd / blkdev_common_ioctl (2) block				3	1070d	1089d	0/26	auto-closed as invalid on 2021/06/19 13:30

================================================================== BUG: KCSAN: data-race in __loop_clr_fd / blkdev_common_ioctl write to 0xffff8881299253f0 of 4 bytes by task 22117 on cpu 0: __loop_clr_fd+0x52e/0x5b0 drivers/block/loop.c:1301 loop_clr_fd drivers/block/loop.c:1345 [inline] lo_ioctl+0x9d1/0x1190 drivers/block/loop.c:1703 __blkdev_driver_ioctl block/ioctl.c:224 [inline] blkdev_ioctl+0x1cf/0x410 block/ioctl.c:620 block_ioctl+0x6d/0x80 fs/block_dev.c:1871 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff8881299253f0 of 4 bytes by task 5078 on cpu 1: disk_max_parts include/linux/genhd.h:232 [inline] disk_part_scan_enabled include/linux/genhd.h:239 [inline] blkdev_reread_part block/ioctl.c:97 [inline] blkdev_common_ioctl+0x55f/0x10b0 block/ioctl.c:549 blkdev_ioctl+0x167/0x410 block/ioctl.c:618 block_ioctl+0x6d/0x80 fs/block_dev.c:1871 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:739 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:739 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 5078 Comm: systemd-udevd Not tainted 5.9.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================