diff options
| author | Alan Stern <stern@rowland.harvard.edu> | 2021-06-07 11:23:07 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-06-09 11:11:39 +0200 |
| commit | 60dfe484cef45293e631b3a6e8995f1689818172 (patch) | |
| tree | 403ba4cb844a2869e6851592dfe82f0caa2a82f9 | |
| parent | 307462a6f5c5a563ec084bb315f4e0279dfb2026 (diff) | |
USB: core: Avoid WARNings for 0-length descriptor requests
The USB core has utility routines to retrieve various types of
descriptors. These routines will now provoke a WARN if they are asked
to retrieve 0 bytes (USB "receive" requests must not have zero
length), so avert this by checking the size argument at the start.
CC: Johan Hovold <johan@kernel.org>
Reported-and-tested-by: syzbot+7dbcd9ff34dc4ed45240@syzkaller.appspotmail.com
Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20210607152307.GD1768031@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/core/message.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index 30e9e680c74c..4d59d927ae3e 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -783,6 +783,9 @@ int usb_get_descriptor(struct usb_device *dev, unsigned char type, int i; int result; + if (size <= 0) /* No point in asking for no data */ + return -EINVAL; + memset(buf, 0, size); /* Make sure we parse really received data */ for (i = 0; i < 3; ++i) { @@ -832,6 +835,9 @@ static int usb_get_string(struct usb_device *dev, unsigned short langid, int i; int result; + if (size <= 0) /* No point in asking for no data */ + return -EINVAL; + for (i = 0; i < 3; ++i) { /* retry on length 0 or stall; some devices are flakey */ result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), |