On Wed, 2023-02-01 at 13:19 +0100, Jiri Pirko wrote:
> Tue, Jan 31, 2023 at 03:20:33PM CET, mikoxyzzz@xxxxxxxxx wrote:
> > syzbot reports that act_len in kalmia_send_init_packet() is
> > uninitialized. Fix this by initializing it to 0.
> >
> > Fixes: d40261236e8e ("net/usb: Add Samsung Kalmia driver for
> > Samsung GT-B3730")
> > Reported-and-tested-by:
> > syzbot+cd80c5ef5121bfe85b55@xxxxxxxxxxxxxxxxxxxxxxxxx
> > Signed-off-by: Miko Larsson <mikoxyzzz@xxxxxxxxx>
> > ---
> > v1 -> v2
> > * Minor alteration of commit message.
> > * Added 'reported-and-tested-by' which is attributed to syzbot.
> >
> > drivers/net/usb/kalmia.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/usb/kalmia.c b/drivers/net/usb/kalmia.c
> > index 9f2b70ef39aa..b158fb7bf66a 100644
> > --- a/drivers/net/usb/kalmia.c
> > +++ b/drivers/net/usb/kalmia.c
> > @@ -56,7 +56,7 @@ static int
> > kalmia_send_init_packet(struct usbnet *dev, u8 *init_msg, u8
> > init_msg_len,
> > u8 *buffer, u8 expected_len)
> > {
> > - int act_len;
> > + int act_len = 0;
> > int status;
> >
> > netdev_dbg(dev->net, "Sending init packet");
>
> Hmm, this is not the right fix.
>
> If the second call of usb_bulk_msg() in this function returns != 0,
> the
> act_len printed out contains the value from previous usb_bulk_msg()
> call,
> which does not make sense.
>
> Printing act_len on error path is pointless, so rather remove it from
> the error message entirely for both usb_bulk_msg() calls.
Something like this, then?
diff --git a/drivers/net/usb/kalmia.c b/drivers/net/usb/kalmia.c
index 9f2b70ef39aa..613fc6910f14 100644
--- a/drivers/net/usb/kalmia.c
+++ b/drivers/net/usb/kalmia.c
@@ -65,8 +65,8 @@ kalmia_send_init_packet(struct usbnet *dev, u8 *init_msg, u8 init_msg_len,
init_msg, init_msg_len, &act_len, KALMIA_USB_TIMEOUT);
if (status != 0) {
netdev_err(dev->net,
- "Error sending init packet. Status %i, length %i\n",
- status, act_len);
+ "Error sending init packet. Status %i\n",
+ status);
return status;
}
else if (act_len != init_msg_len) {
@@ -83,8 +83,8 @@ kalmia_send_init_packet(struct usbnet *dev, u8 *init_msg, u8 init_msg_len,
if (status != 0)
netdev_err(dev->net,
- "Error receiving init result. Status %i, length %i\n",
- status, act_len);
+ "Error receiving init result. Status %i\n",
+ status);
else if (act_len != expected_len)
netdev_err(dev->net, "Unexpected init result length: %i\n",
act_len);
--
~miko
