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authorJohan Hovold <johan@kernel.org>2017-01-31 17:17:27 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-03-18 19:09:55 +0800
commit4d95645f3dd5b1e8453d65220f604c39e822d990 (patch)
treeed689493da1a68ed27440f98f51fc8e8620a7112
parent804a935963a91acd1764ba914f825dd2a29c5871 (diff)
downloadlinux-linaro-stable-4d95645f3dd5b1e8453d65220f604c39e822d990.tar.gz
USB: serial: digi_acceleport: fix OOB data sanity check
commit 2d380889215fe20b8523345649dee0579821800c upstream. Make sure to check for short transfers to avoid underflow in a loop condition when parsing the receive buffer. Also fix an off-by-one error in the incomplete sanity check which could lead to invalid data being parsed. Fixes: 8c209e6782ca ("USB: make actual_length in struct urb field u32") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/serial/digi_acceleport.c14
1 files changed, 9 insertions, 5 deletions
diff --git a/drivers/usb/serial/digi_acceleport.c b/drivers/usb/serial/digi_acceleport.c
index 3df7b7ec178e..19c3bef426c3 100644
--- a/drivers/usb/serial/digi_acceleport.c
+++ b/drivers/usb/serial/digi_acceleport.c
@@ -1483,16 +1483,20 @@ static int digi_read_oob_callback(struct urb *urb)
struct usb_serial *serial = port->serial;
struct tty_struct *tty;
struct digi_port *priv = usb_get_serial_port_data(port);
+ unsigned char *buf = urb->transfer_buffer;
int opcode, line, status, val;
int i;
unsigned int rts;
+ if (urb->actual_length < 4)
+ return -1;
+
/* handle each oob command */
- for (i = 0; i < urb->actual_length - 3;) {
- opcode = ((unsigned char *)urb->transfer_buffer)[i++];
- line = ((unsigned char *)urb->transfer_buffer)[i++];
- status = ((unsigned char *)urb->transfer_buffer)[i++];
- val = ((unsigned char *)urb->transfer_buffer)[i++];
+ for (i = 0; i < urb->actual_length - 4; i += 4) {
+ opcode = buf[i];
+ line = buf[i + 1];
+ status = buf[i + 2];
+ val = buf[i + 3];
dev_dbg(&port->dev, "digi_read_oob_callback: opcode=%d, line=%d, status=%d, val=%d\n",
opcode, line, status, val);