Fuzzing uncovered race condition between sysfs code paths in usbip
drivers. Device connect/disconnect code paths initiated through
sysfs interface are prone to races if disconnect happens during
connect and vice versa.
Use sysfs_lock to synchronize event handler with sysfs paths
in usbip drivers.
Reported-and-tested-by: syzbot+a93fba6d384346a761e3@xxxxxxxxxxxxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/usbip/usbip_event.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/usb/usbip/usbip_event.c b/drivers/usb/usbip/usbip_event.c
index 5d88917c9631..086ca76dd053 100644
--- a/drivers/usb/usbip/usbip_event.c
+++ b/drivers/usb/usbip/usbip_event.c
@@ -70,6 +70,7 @@ static void event_handler(struct work_struct *work)
while ((ud = get_event()) != NULL) {
usbip_dbg_eh("pending event %lx\n", ud->event);
+ mutex_lock(&ud->sysfs_lock);
/*
* NOTE: shutdown must come first.
* Shutdown the device.
@@ -90,6 +91,7 @@ static void event_handler(struct work_struct *work)
ud->eh_ops.unusable(ud);
unset_event(ud, USBIP_EH_UNUSABLE);
}
+ mutex_unlock(&ud->sysfs_lock);
wake_up(&ud->eh_waitq);
}
--
2.27.0
