blob: 76b93b6079fbb15858bba8004ae013a26a73cf28 [file] [log] [blame]
From 3cf7c29fad9325543ccad616e7115dbd0b6f79d5 Mon Sep 17 00:00:00 2001
From: Alan Stern <>
Date: Tue, 17 Sep 2019 12:47:23 -0400
Subject: [PATCH] USB: yurex: Don't retry on unexpected errors
commit 32a0721c6620b77504916dac0cea8ad497c4878a upstream.
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.
Signed-off-by: Alan Stern <>
CC: Tomoki Sekiyama <>
CC: <>
Signed-off-by: Greg Kroah-Hartman <>
Signed-off-by: Paul Gortmaker <>
diff --git a/drivers/usb/misc/yurex.c b/drivers/usb/misc/yurex.c
index 6715a128e6c8..8d52d4336c29 100644
--- a/drivers/usb/misc/yurex.c
+++ b/drivers/usb/misc/yurex.c
@@ -132,6 +132,7 @@ static void yurex_interrupt(struct urb *urb)
switch (status) {
case 0: /*success*/
+ /* The device is terminated or messed up, give up */
"%s - overflow with length %d, actual length is %d\n",
@@ -140,12 +141,13 @@ static void yurex_interrupt(struct urb *urb)
case -ENOENT:
case -EILSEQ:
- /* The device is terminated, clean up */
+ case -EPROTO:
+ case -ETIME:
"%s - unknown status received: %d\n", __func__, status);
- goto exit;
+ return;
/* handle received message */
@@ -177,7 +179,6 @@ static void yurex_interrupt(struct urb *urb)
retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
if (retval) {
dev_err(&dev->interface->dev, "%s - usb_submit_urb failed: %d\n",