@@ -39,8 +39,8 @@ static DEVICE_ATTR_RO(usbip_status);
* is used to transfer usbip requests by kernel threads. -1 is a magic number
* by which usbip connection is finished.
*/
-static ssize_t usbip_sockfd_store(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
+static ssize_t __usbip_sockfd_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
{
struct stub_device *sdev = dev_get_drvdata(dev);
int sockfd = 0;
@@ -104,6 +104,17 @@ static ssize_t usbip_sockfd_store(struct device *dev, struct device_attribute *a
spin_unlock_irq(&sdev->ud.lock);
return -EINVAL;
}
+static ssize_t usbip_sockfd_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ ssize_t ret = usbip_event_lock_killable();
+
+ if (ret)
+ return ret;
+ ret = __usbip_sockfd_store(dev, attr, buf, count);
+ usbip_event_unlock();
+ return ret;
+}
static DEVICE_ATTR_WO(usbip_sockfd);
static struct attribute *usbip_attrs[] = {
usbip_sockfd_store() must perform if (sdev->ud.status != SDEV_ST_AVAILABLE) { /* misc assignments for attach operation */ sdev->ud.status = SDEV_ST_USED; } under a lock, or multiple ud->tcp_{tx,rx} are created (which will later cause a crash like [1]) and refcount on ud->tcp_socket is leaked when usbip_sockfd_store() is concurrently called. Since I don't want to replace "return" with "goto" in order to call usbip_event_unlock(), wrap whole function in order to keep changes minimal. [1] https://syzkaller.appspot.com/bug?extid=95ce4b142579611ef0a9 Reported-by: syzbot <syzbot+95ce4b142579611ef0a9@syzkaller.appspotmail.com> Tested-by: syzbot <syzbot+a93fba6d384346a761e3@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> --- drivers/usb/usbip/stub_dev.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-)