[PATCH][next] ALSA: usb-audio: Fix sum of uninitialized variable sample_accum
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 --- 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];
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
participants (3)
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Colin Ian King -
Colin King
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Takashi Iwai