KCSAN: data-race in lo_ioctl / lo

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in lo_ioctl / lo_ioctl (2) block	6				1	623d	623d	0/29	auto-obsoleted due to no activity on 2024/01/20 15:05

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BUG: KCSAN: data-race in lo_ioctl / lo_ioctl

read-write to 0xffff88810246010c of 1 bytes by task 18761 on cpu 1:
 dev_set_uevent_suppress include/linux/device.h:904 [inline]
 loop_change_fd drivers/block/loop.c:578 [inline]
 lo_ioctl+0x243/0x12e0 drivers/block/loop.c:1561
 blkdev_ioctl+0x375/0x460 block/ioctl.c:621
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xcf/0x140 fs/ioctl.c:856
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read-write to 0xffff88810246010c of 1 bytes by task 18762 on cpu 0:
 dev_set_uevent_suppress include/linux/device.h:904 [inline]
 loop_change_fd drivers/block/loop.c:638 [inline]
 lo_ioctl+0x1254/0x12e0 drivers/block/loop.c:1561
 blkdev_ioctl+0x375/0x460 block/ioctl.c:621
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xcf/0x140 fs/ioctl.c:856
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x17 -> 0x07

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 18762 Comm: syz-executor.0 Not tainted 6.5.0-rc1-syzkaller-00006-g3f01e9fed845 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
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Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Assets (help?)	Manager	Title
2023/07/11 11:42	upstream	3f01e9fed845	f8780940	.config	console log	report			info	[disk image] [vmlinux] [kernel image]	ci2-upstream-kcsan-gce	KCSAN: data-race in lo_ioctl / lo_ioctl
2023/06/14 23:48	upstream	b6dad5178cea	76decb82	.config	console log	report			info		ci2-upstream-kcsan-gce	KCSAN: data-race in lo_ioctl / lo_ioctl