syzbot


KCSAN: data-race in kobject_uevent_env / loop_configure

Status: auto-closed as invalid on 2022/07/23 00:26
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 171d, last: 171d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in kobject_uevent_env / loop_configure

read to 0xffff8881027b0784 of 1 bytes by task 16032 on cpu 0:
 kobject_uevent_env+0xaf/0x580 lib/kobject_uevent.c:496
 disk_event_uevent block/disk-events.c:181 [inline]
 disk_force_media_change+0xe3/0x180 block/disk-events.c:305
 loop_configure+0x730/0xc20 drivers/block/loop.c:1065
 lo_ioctl+0x641/0x1290
 blkdev_ioctl+0x20e/0x440 block/ioctl.c:614
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:856
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

read-write to 0xffff8881027b0784 of 1 bytes by task 16030 on cpu 1:
 dev_set_uevent_suppress include/linux/device.h:781 [inline]
 loop_configure+0x128/0xc20 drivers/block/loop.c:1009
 lo_ioctl+0x641/0x1290
 blkdev_ioctl+0x20e/0x440 block/ioctl.c:614
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:856
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

value changed: 0x17 -> 0x07

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 16030 Comm: syz-executor.4 Not tainted 5.19.0-rc2-syzkaller-00205-g462abc9de7a1-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
Buffer I/O error on dev loop4, logical block 0, async page read
 loop4: unable to read partition table
loop4: partition table beyond EOD, truncated
I/O error, dev loop4, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0
Buffer I/O error on dev loop4, logical block 0, async page read
 loop4: unable to read partition table
loop4: partition table beyond EOD, truncated

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/06/18 00:20 upstream 462abc9de7a1 8f633d84 .config log report info KCSAN: data-race in kobject_uevent_env / loop_configure
* Struck through repros no longer work on HEAD.