Hi,
On 01/13/2011 11:05 PM, Jesper Juhl wrote:
usb_altnum_to_altsetting() may return NULL. If it does we'll dereference a
NULL pointer in
drivers/media/video/gspca/stv06xx/stv06xx_pb0100.c::pb0100_start().
As far as I can tell there's not really anything more sensible than
-ENODEV that we can return in that situation, but I'm not at all intimate
with this code so I'd like a bit of review/comments on this before it's
applied.
Anyway, here's a proposed patch.
Hi,
On 01/13/2011 11:05 PM, Jesper Juhl wrote:
> usb_altnum_to_altsetting() may return NULL. If it does we'll dereference a
> NULL pointer in
> drivers/media/video/gspca/stv06xx/stv06xx_pb0100.c::pb0100_start().
> As far as I can tell there's not really anything more sensible than
> -ENODEV that we can return in that situation, but I'm not at all intimate
> with this code so I'd like a bit of review/comments on this before it's
> applied.
> Anyway, here's a proposed patch.
>
pb0100_start gets called from stv06xx_start, which also does a
usb_altnum_to_altsetting(intf, sd->gspca_dev.alt); and does contain the
NULL check before calling pb0100_start. So I left out the check on purpose,
to keep the code compact in IMHO better readable.
Still I agree this is a bit tricky. So not NACK but not ACK either. What
do others think?
Regards,
Hans
Signed-off-by: Jesper Juhl<j...@chaosbits.net>
---
stv06xx_pb0100.c | 2 ++
1 file changed, 2 insertions(+)
compile tested only.
diff --git a/drivers/media/video/gspca/stv06xx/stv06xx_pb0100.c
b/drivers/media/video/gspca/stv06xx/stv06xx_pb0100.c
index ac47b4c..75a5b9c 100644
--- a/drivers/media/video/gspca/stv06xx/stv06xx_pb0100.c
+++ b/drivers/media/video/gspca/stv06xx/stv06xx_pb0100.c
@@ -217,6 +217,8 @@ static int pb0100_start(struct sd *sd)
intf = usb_ifnum_to_if(sd->gspca_dev.dev, sd->gspca_dev.iface);
alt = usb_altnum_to_altsetting(intf, sd->gspca_dev.alt);
+ if (!alt)
+ return -ENODEV;
packet_size = le16_to_cpu(alt->endpoint[0].desc.wMaxPacketSize);
/* If we don't have enough bandwidth use a lower framerate */
--
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