| Message ID | 20211026095511.26673-1-johan@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | media: uvcvideo: fix division by zero at stream start | expand |
Quoting Johan Hovold (2021-10-26 10:55:11) > Add the missing bulk-endpoint max-packet sanity check to probe() to > avoid division by zero in uvc_alloc_urb_buffers() in case a malicious > device has broken descriptors (or when doing descriptor fuzz testing). > > Note that USB core will reject URBs submitted for endpoints with zero > wMaxPacketSize but that drivers doing packet-size calculations still > need to handle this (cf. commit 2548288b4fb0 ("USB: Fix: Don't skip > endpoint descriptors with maxpacket=0")). > > Fixes: c0efd232929c ("V4L/DVB (8145a): USB Video Class driver") > Cc: stable@vger.kernel.org # 2.6.26 > Signed-off-by: Johan Hovold <johan@kernel.org> > --- > drivers/media/usb/uvc/uvc_video.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c > index e16464606b14..85ac5c1081b6 100644 > --- a/drivers/media/usb/uvc/uvc_video.c > +++ b/drivers/media/usb/uvc/uvc_video.c > @@ -1958,6 +1958,10 @@ static int uvc_video_start_transfer(struct uvc_streaming *stream, > if (ep == NULL) > return -EIO; > > + /* Reject broken descriptors. */ > + if (usb_endpoint_maxp(&ep->desc) == 0) > + return -EIO; Is there any value in identifying this with a specific return code like -ENODATA? But either way, this seems sane. Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> > + > ret = uvc_init_video_bulk(stream, ep, gfp_flags); > } > > -- > 2.32.0 >
On Tue, Oct 26, 2021 at 11:55:05AM +0100, Kieran Bingham wrote: > Quoting Johan Hovold (2021-10-26 10:55:11) > > Add the missing bulk-endpoint max-packet sanity check to probe() to > > avoid division by zero in uvc_alloc_urb_buffers() in case a malicious > > device has broken descriptors (or when doing descriptor fuzz testing). > > > > Note that USB core will reject URBs submitted for endpoints with zero > > wMaxPacketSize but that drivers doing packet-size calculations still > > need to handle this (cf. commit 2548288b4fb0 ("USB: Fix: Don't skip > > endpoint descriptors with maxpacket=0")). > > > > Fixes: c0efd232929c ("V4L/DVB (8145a): USB Video Class driver") > > Cc: stable@vger.kernel.org # 2.6.26 > > Signed-off-by: Johan Hovold <johan@kernel.org> > > --- > > drivers/media/usb/uvc/uvc_video.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c > > index e16464606b14..85ac5c1081b6 100644 > > --- a/drivers/media/usb/uvc/uvc_video.c > > +++ b/drivers/media/usb/uvc/uvc_video.c > > @@ -1958,6 +1958,10 @@ static int uvc_video_start_transfer(struct uvc_streaming *stream, > > if (ep == NULL) > > return -EIO; > > > > + /* Reject broken descriptors. */ > > + if (usb_endpoint_maxp(&ep->desc) == 0) > > + return -EIO; > > Is there any value in identifying this with a specific return code like > -ENODATA? Going one step further, wouldn't it be better to fail probe() for those devices ? > But either way, this seems sane. > > Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> > > > + > > ret = uvc_init_video_bulk(stream, ep, gfp_flags); > > } > >
On Tue, Oct 26, 2021 at 02:15:20PM +0300, Laurent Pinchart wrote: > On Tue, Oct 26, 2021 at 11:55:05AM +0100, Kieran Bingham wrote: > > Quoting Johan Hovold (2021-10-26 10:55:11) > > > Add the missing bulk-endpoint max-packet sanity check to probe() to > > > avoid division by zero in uvc_alloc_urb_buffers() in case a malicious > > > device has broken descriptors (or when doing descriptor fuzz testing). > > > > > > Note that USB core will reject URBs submitted for endpoints with zero > > > wMaxPacketSize but that drivers doing packet-size calculations still > > > need to handle this (cf. commit 2548288b4fb0 ("USB: Fix: Don't skip > > > endpoint descriptors with maxpacket=0")). > > > > > > Fixes: c0efd232929c ("V4L/DVB (8145a): USB Video Class driver") > > > Cc: stable@vger.kernel.org # 2.6.26 > > > Signed-off-by: Johan Hovold <johan@kernel.org> > > > --- > > > drivers/media/usb/uvc/uvc_video.c | 4 ++++ > > > 1 file changed, 4 insertions(+) > > > > > > diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c > > > index e16464606b14..85ac5c1081b6 100644 > > > --- a/drivers/media/usb/uvc/uvc_video.c > > > +++ b/drivers/media/usb/uvc/uvc_video.c > > > @@ -1958,6 +1958,10 @@ static int uvc_video_start_transfer(struct uvc_streaming *stream, > > > if (ep == NULL) > > > return -EIO; > > > > > > + /* Reject broken descriptors. */ > > > + if (usb_endpoint_maxp(&ep->desc) == 0) > > > + return -EIO; > > > > Is there any value in identifying this with a specific return code like > > -ENODATA? > > Going one step further, wouldn't it be better to fail probe() for those > devices ? This is not how the driver works today. Look at the "return -EIO" just above in case the expected endpoint is missing. And similarly for the isochronous case for which zero wMaxPacket isn't handled until uvc_video_start_transfer() either (a few lines further up still). Note however the copy-paste error in the commit message mentioning probe(), which is indeed where this would typically be handled. Do you want me to resend or can you change s/probe()/uvc_video_start_transfer()/ in the commit message when applying if you think this is acceptable as is? Johan
Hi Johan, On Tue, Oct 26, 2021 at 02:06:55PM +0200, Johan Hovold wrote: > On Tue, Oct 26, 2021 at 02:15:20PM +0300, Laurent Pinchart wrote: > > On Tue, Oct 26, 2021 at 11:55:05AM +0100, Kieran Bingham wrote: > > > Quoting Johan Hovold (2021-10-26 10:55:11) > > > > Add the missing bulk-endpoint max-packet sanity check to probe() to > > > > avoid division by zero in uvc_alloc_urb_buffers() in case a malicious > > > > device has broken descriptors (or when doing descriptor fuzz testing). > > > > > > > > Note that USB core will reject URBs submitted for endpoints with zero > > > > wMaxPacketSize but that drivers doing packet-size calculations still > > > > need to handle this (cf. commit 2548288b4fb0 ("USB: Fix: Don't skip > > > > endpoint descriptors with maxpacket=0")). > > > > > > > > Fixes: c0efd232929c ("V4L/DVB (8145a): USB Video Class driver") > > > > Cc: stable@vger.kernel.org # 2.6.26 > > > > Signed-off-by: Johan Hovold <johan@kernel.org> > > > > --- > > > > drivers/media/usb/uvc/uvc_video.c | 4 ++++ > > > > 1 file changed, 4 insertions(+) > > > > > > > > diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c > > > > index e16464606b14..85ac5c1081b6 100644 > > > > --- a/drivers/media/usb/uvc/uvc_video.c > > > > +++ b/drivers/media/usb/uvc/uvc_video.c > > > > @@ -1958,6 +1958,10 @@ static int uvc_video_start_transfer(struct uvc_streaming *stream, > > > > if (ep == NULL) > > > > return -EIO; > > > > > > > > + /* Reject broken descriptors. */ > > > > + if (usb_endpoint_maxp(&ep->desc) == 0) > > > > + return -EIO; > > > > > > Is there any value in identifying this with a specific return code like > > > -ENODATA? > > > > Going one step further, wouldn't it be better to fail probe() for those > > devices ? > > This is not how the driver works today. Look at the "return -EIO" just > above in case the expected endpoint is missing. And similarly for the > isochronous case for which zero wMaxPacket isn't handled until > uvc_video_start_transfer() either (a few lines further up still). That's a good point, it wouldn't be reasonable to ask you to fix all that :-) > Note however the copy-paste error in the commit message mentioning > probe(), which is indeed where this would typically be handled. > > Do you want me to resend or can you change > > s/probe()/uvc_video_start_transfer()/ > > in the commit message when applying if you think this is acceptable as > is? I can fix this when applying. Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
On Wed, Oct 27, 2021 at 12:50:46AM +0300, Laurent Pinchart wrote: > Hi Johan, > > On Tue, Oct 26, 2021 at 02:06:55PM +0200, Johan Hovold wrote: > > Do you want me to resend or can you change > > > > s/probe()/uvc_video_start_transfer()/ > > > > in the commit message when applying if you think this is acceptable as > > is? > > I can fix this when applying. Perfect, thanks. > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Johan
Hi Laurent, On Wed, Oct 27, 2021 at 12:50:46AM +0300, Laurent Pinchart wrote: > Hi Johan, > > On Tue, Oct 26, 2021 at 02:06:55PM +0200, Johan Hovold wrote: > > On Tue, Oct 26, 2021 at 02:15:20PM +0300, Laurent Pinchart wrote: > > > On Tue, Oct 26, 2021 at 11:55:05AM +0100, Kieran Bingham wrote: > > > > Quoting Johan Hovold (2021-10-26 10:55:11) > > > > > Add the missing bulk-endpoint max-packet sanity check to probe() to > > > > > avoid division by zero in uvc_alloc_urb_buffers() in case a malicious > > > > > device has broken descriptors (or when doing descriptor fuzz testing). > > > > > > > > > > Note that USB core will reject URBs submitted for endpoints with zero > > > > > wMaxPacketSize but that drivers doing packet-size calculations still > > > > > need to handle this (cf. commit 2548288b4fb0 ("USB: Fix: Don't skip > > > > > endpoint descriptors with maxpacket=0")). > > > > > > > > > > Fixes: c0efd232929c ("V4L/DVB (8145a): USB Video Class driver") > > > > > Cc: stable@vger.kernel.org # 2.6.26 > > > > > Signed-off-by: Johan Hovold <johan@kernel.org> > > Note however the copy-paste error in the commit message mentioning > > probe(), which is indeed where this would typically be handled. > > > > Do you want me to resend or can you change > > > > s/probe()/uvc_video_start_transfer()/ > > > > in the commit message when applying if you think this is acceptable as > > is? > > I can fix this when applying. > > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> I noticed that this one hasn't showed up in linux-next yet. Do you still have it in your queue or do you want me to resend? Johan
Hi Johan, On Fri, Dec 03, 2021 at 11:29:07AM +0100, Johan Hovold wrote: > On Wed, Oct 27, 2021 at 12:50:46AM +0300, Laurent Pinchart wrote: > > On Tue, Oct 26, 2021 at 02:06:55PM +0200, Johan Hovold wrote: > > > On Tue, Oct 26, 2021 at 02:15:20PM +0300, Laurent Pinchart wrote: > > > > On Tue, Oct 26, 2021 at 11:55:05AM +0100, Kieran Bingham wrote: > > > > > Quoting Johan Hovold (2021-10-26 10:55:11) > > > > > > Add the missing bulk-endpoint max-packet sanity check to probe() to > > > > > > avoid division by zero in uvc_alloc_urb_buffers() in case a malicious > > > > > > device has broken descriptors (or when doing descriptor fuzz testing). > > > > > > > > > > > > Note that USB core will reject URBs submitted for endpoints with zero > > > > > > wMaxPacketSize but that drivers doing packet-size calculations still > > > > > > need to handle this (cf. commit 2548288b4fb0 ("USB: Fix: Don't skip > > > > > > endpoint descriptors with maxpacket=0")). > > > > > > > > > > > > Fixes: c0efd232929c ("V4L/DVB (8145a): USB Video Class driver") > > > > > > Cc: stable@vger.kernel.org # 2.6.26 > > > > > > Signed-off-by: Johan Hovold <johan@kernel.org> > > > > > > Note however the copy-paste error in the commit message mentioning > > > probe(), which is indeed where this would typically be handled. > > > > > > Do you want me to resend or can you change > > > > > > s/probe()/uvc_video_start_transfer()/ > > > > > > in the commit message when applying if you think this is acceptable as > > > is? > > > > I can fix this when applying. > > > > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > > I noticed that this one hasn't showed up in linux-next yet. Do you still > have it in your queue or do you want me to resend? It should be in Mauro's queue now: https://lore.kernel.org/all/YacOun3Diggsi05V@pendragon.ideasonboard.com/
On Fri, Dec 03, 2021 at 12:52:19PM +0200, Laurent Pinchart wrote: > > I noticed that this one hasn't showed up in linux-next yet. Do you still > > have it in your queue or do you want me to resend? > > It should be in Mauro's queue now: > > https://lore.kernel.org/all/YacOun3Diggsi05V@pendragon.ideasonboard.com/ Perfect, thanks! Johan
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c index e16464606b14..85ac5c1081b6 100644 --- a/drivers/media/usb/uvc/uvc_video.c +++ b/drivers/media/usb/uvc/uvc_video.c @@ -1958,6 +1958,10 @@ static int uvc_video_start_transfer(struct uvc_streaming *stream, if (ep == NULL) return -EIO; + /* Reject broken descriptors. */ + if (usb_endpoint_maxp(&ep->desc) == 0) + return -EIO; + ret = uvc_init_video_bulk(stream, ep, gfp_flags); }
Add the missing bulk-endpoint max-packet sanity check to probe() to avoid division by zero in uvc_alloc_urb_buffers() in case a malicious device has broken descriptors (or when doing descriptor fuzz testing). Note that USB core will reject URBs submitted for endpoints with zero wMaxPacketSize but that drivers doing packet-size calculations still need to handle this (cf. commit 2548288b4fb0 ("USB: Fix: Don't skip endpoint descriptors with maxpacket=0")). Fixes: c0efd232929c ("V4L/DVB (8145a): USB Video Class driver") Cc: stable@vger.kernel.org # 2.6.26 Signed-off-by: Johan Hovold <johan@kernel.org> --- drivers/media/usb/uvc/uvc_video.c | 4 ++++ 1 file changed, 4 insertions(+)