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authorAlan Stern <stern@rowland.harvard.edu>2019-09-17 19:47:23 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-10-04 12:02:59 +0300
commit32a0721c6620b77504916dac0cea8ad497c4878a (patch)
tree9b5a494c20b969ad14890329dcbfbf44e1e34743 /drivers/usb
parentb2fa7baee744fde746c17bc1860b9c6f5c2eebb7 (diff)
downloadlinux-32a0721c6620b77504916dac0cea8ad497c4878a.tar.xz
USB: yurex: Don't retry on unexpected errors
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> Link: https://lore.kernel.org/r/Pine.LNX.4.44L0.1909171245410.1590-100000@iolanthe.rowland.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/misc/yurex.c7
1 files changed, 4 insertions, 3 deletions
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*/
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 *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 *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",