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| author | Alan Stern <stern@rowland.harvard.edu> | 2019-09-17 19:47:23 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-04 12:02:59 +0300 |
| commit | 32a0721c6620b77504916dac0cea8ad497c4878a (patch) | |
| tree | 9b5a494c20b969ad14890329dcbfbf44e1e34743 /drivers/usb | |
| parent | b2fa7baee744fde746c17bc1860b9c6f5c2eebb7 (diff) | |
| download | linux-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.c | 7 |
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", |