===================================================================
@@ -132,6 +132,7 @@ static void yurex_interrupt(struct urb *
switch (status) {
case 0: /*success*/
break;
+ /* The device is terminated or messed up, give up */
case -EOVERFLOW:
dev_err(&dev->interface->dev,
"%s - overflow with length %d, actual length is %d\n",
@@ -140,12 +141,13 @@ static void yurex_interrupt(struct urb *
case -ENOENT:
case -ESHUTDOWN:
case -EILSEQ:
- /* The device is terminated, clean up */
+ case -EPROTO:
+ case -ETIME:
return;
default:
dev_err(&dev->interface->dev,
"%s - unknown status received: %d\n", __func__, status);
- goto exit;
+ return;
}
/* handle received message */
@@ -177,7 +179,6 @@ static void yurex_interrupt(struct urb *
break;
}
-exit:
retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
if (retval) {
dev_err(&dev->interface->dev, "%s - usb_submit_urb failed: %d\n",
According to Greg KH, it has been generally agreed that when a USB driver encounters an unknown error (or one it can't handle directly), it should just give up instead of going into a potentially infinite retry loop. The three codes -EPROTO, -EILSEQ, and -ETIME fall into this category. They can be caused by bus errors such as packet loss or corruption, attempting to communicate with a disconnected device, or by malicious firmware. Nowadays the extent of packet loss or corruption is negligible, so it should be safe for a driver to give up whenever one of these errors occurs. Although the yurex driver handles -EILSEQ errors in this way, it doesn't do the same for -EPROTO (as discovered by the syzbot fuzzer) or other unrecognized errors. This patch adjusts the driver so that it doesn't log an error message for -EPROTO or -ETIME, and it doesn't retry after any errors. Reported-and-tested-by: syzbot+b24d736f18a1541ad550@syzkaller.appspotmail.com Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: Tomoki Sekiyama <tomoki.sekiyama@gmail.com> CC: <stable@vger.kernel.org> --- [as1918] drivers/usb/misc/yurex.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)