| Message ID | 20211001104417.14291-1-colin.king@canonical.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [next] ALSA: usb-audio: Fix sum of uninitialized variable sample_accum | expand |
On Fri, 01 Oct 2021 12:44:17 +0200, Colin King wrote: > > From: Colin Ian King <colin.king@canonical.com> > > Variable sample_accum is not being intialized and then has > ep->sample_rem added to it, leading to a bogus value. One solution > is to initialize it to zero at declaration time, but it is probably > best to just assign it to ep->sample_rem on first use. > > Addresses-Coveriry: ("Uninitialized scalar variable") > Fixes: f0bd62b64016 ("ALSA: usb-audio: Improve frames size computation") > Signed-off-by: Colin Ian King <colin.king@canonical.com> Thanks for the patch, but it's no right fix. The Fixes tag points to a wrong commit, it was d215f63d49da9a8803af3e81acd6cad743686573 ALSA: usb-audio: Check available frames for the next packet size And sample_accum has to be initialized from ep->sample_accum instead. I'll post the proper fix. Takashi > --- > sound/usb/endpoint.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c > index 42c0d2db8ba8..c6a33732db3f 100644 > --- a/sound/usb/endpoint.c > +++ b/sound/usb/endpoint.c > @@ -182,7 +182,7 @@ static int next_packet_size(struct snd_usb_endpoint *ep, unsigned int avail) > if (ep->fill_max) > return ep->maxframesize; > > - sample_accum += ep->sample_rem; > + sample_accum = ep->sample_rem; > if (sample_accum >= ep->pps) { > sample_accum -= ep->pps; > ret = ep->packsize[1]; > -- > 2.32.0 >
On 01/10/2021 11:48, Takashi Iwai wrote: > On Fri, 01 Oct 2021 12:44:17 +0200, > Colin King wrote: >> >> From: Colin Ian King <colin.king@canonical.com> >> >> Variable sample_accum is not being intialized and then has >> ep->sample_rem added to it, leading to a bogus value. One solution >> is to initialize it to zero at declaration time, but it is probably >> best to just assign it to ep->sample_rem on first use. >> >> Addresses-Coveriry: ("Uninitialized scalar variable") >> Fixes: f0bd62b64016 ("ALSA: usb-audio: Improve frames size computation") >> Signed-off-by: Colin Ian King <colin.king@canonical.com> > > Thanks for the patch, but it's no right fix. The Fixes tag points to > a wrong commit, it was d215f63d49da9a8803af3e81acd6cad743686573 > ALSA: usb-audio: Check available frames for the next packet size > > And sample_accum has to be initialized from ep->sample_accum instead. > I'll post the proper fix. Thanks Takshi. Colin > > > Takashi > > >> --- >> sound/usb/endpoint.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c >> index 42c0d2db8ba8..c6a33732db3f 100644 >> --- a/sound/usb/endpoint.c >> +++ b/sound/usb/endpoint.c >> @@ -182,7 +182,7 @@ static int next_packet_size(struct snd_usb_endpoint *ep, unsigned int avail) >> if (ep->fill_max) >> return ep->maxframesize; >> >> - sample_accum += ep->sample_rem; >> + sample_accum = ep->sample_rem; >> if (sample_accum >= ep->pps) { >> sample_accum -= ep->pps; >> ret = ep->packsize[1]; >> -- >> 2.32.0 >>
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c index 42c0d2db8ba8..c6a33732db3f 100644 --- a/sound/usb/endpoint.c +++ b/sound/usb/endpoint.c @@ -182,7 +182,7 @@ static int next_packet_size(struct snd_usb_endpoint *ep, unsigned int avail) if (ep->fill_max) return ep->maxframesize; - sample_accum += ep->sample_rem; + sample_accum = ep->sample_rem; if (sample_accum >= ep->pps) { sample_accum -= ep->pps; ret = ep->packsize[1];