[v1] ALSA: virtio: Fix "Coverity: virtsnd_kctl_tlv_op(): Uninitialized variables" warning.

[PATCH] ALSA: virtio: Fix "Coverity: virtsnd_kctl_tlv_op(): Uninitialized variables" warning.

Posted by Aiswarya Cyriac 1 year, 10 months ago

Fix the following warning when building virtio_snd driver.

"
*** CID 1583619:  Uninitialized variables  (UNINIT)
sound/virtio/virtio_kctl.c:294 in virtsnd_kctl_tlv_op()
288
289         break;
290       }
291
292       kfree(tlv);
293
vvv     CID 1583619:  Uninitialized variables  (UNINIT)
vvv     Using uninitialized value "rc".
294       return rc;
295     }
296
297     /**
298      * virtsnd_kctl_get_enum_items() - Query items for the ENUMERATED element type.
299      * @snd: VirtIO sound device.
"

Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
Signed-off-by: Aiswarya Cyriac <aiswarya.cyriac@opensynergy.com>
Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1583619 ("Uninitialized variables")
Fixes: d6568e3de42d ("ALSA: virtio: add support for audio controls")
---
 sound/virtio/virtio_kctl.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/sound/virtio/virtio_kctl.c b/sound/virtio/virtio_kctl.c
index 0c6ac74aca1e..d7a160c5db03 100644
--- a/sound/virtio/virtio_kctl.c
+++ b/sound/virtio/virtio_kctl.c
@@ -286,6 +286,11 @@ static int virtsnd_kctl_tlv_op(struct snd_kcontrol *kcontrol, int op_flag,
 		else
 			rc = virtsnd_ctl_msg_send(snd, msg, &sg, NULL, false);
 
+		break;
+	default:
+		virtsnd_ctl_msg_unref(msg);
+		rc = -EINVAL;
+
 		break;
 	}
 
-- 
2.43.0

Re: [PATCH] ALSA: virtio: Fix "Coverity: virtsnd_kctl_tlv_op(): Uninitialized variables" warning.

Posted by Michael S. Tsirkin 1 year, 10 months ago

On Tue, Feb 13, 2024 at 09:51:30AM +0100, Aiswarya Cyriac wrote:
> Fix the following warning when building virtio_snd driver.
> 
> "
> *** CID 1583619:  Uninitialized variables  (UNINIT)
> sound/virtio/virtio_kctl.c:294 in virtsnd_kctl_tlv_op()
> 288
> 289         break;
> 290       }
> 291
> 292       kfree(tlv);
> 293
> vvv     CID 1583619:  Uninitialized variables  (UNINIT)
> vvv     Using uninitialized value "rc".
> 294       return rc;
> 295     }
> 296
> 297     /**
> 298      * virtsnd_kctl_get_enum_items() - Query items for the ENUMERATED element type.
> 299      * @snd: VirtIO sound device.
> "
> 
> Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
> Signed-off-by: Aiswarya Cyriac <aiswarya.cyriac@opensynergy.com>
> Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
> Addresses-Coverity-ID: 1583619 ("Uninitialized variables")
> Fixes: d6568e3de42d ("ALSA: virtio: add support for audio controls")

I don't know enough about ALSA to say whether the patch is correct.  But
the commit log needs work: please, do not "fix warnings" - analyse the
code and explain whether there is a real issue and if yes what is it
and how it can trigger. Is an invalid op_flag ever passed?
If it's just a coverity false positive it might be ok to
work around that but document this.


> ---
>  sound/virtio/virtio_kctl.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/sound/virtio/virtio_kctl.c b/sound/virtio/virtio_kctl.c
> index 0c6ac74aca1e..d7a160c5db03 100644
> --- a/sound/virtio/virtio_kctl.c
> +++ b/sound/virtio/virtio_kctl.c
> @@ -286,6 +286,11 @@ static int virtsnd_kctl_tlv_op(struct snd_kcontrol *kcontrol, int op_flag,
>  		else
>  			rc = virtsnd_ctl_msg_send(snd, msg, &sg, NULL, false);
>  
> +		break;
> +	default:
> +		virtsnd_ctl_msg_unref(msg);
> +		rc = -EINVAL;
> +

There's already virtsnd_ctl_msg_unref call above.
Also don't we need virtsnd_ctl_msg_unref on other error paths
such as EFAULT?
Unify error handling to fix it all then?

>  		break;
>  	}
>  
> -- 
> 2.43.0

Re: [PATCH] ALSA: virtio: Fix "Coverity: virtsnd_kctl_tlv_op(): Uninitialized variables" warning.

Posted by Takashi Iwai 1 year, 10 months ago

On Tue, 13 Feb 2024 09:51:30 +0100,
Aiswarya Cyriac wrote:
> 
> Fix the following warning when building virtio_snd driver.
> 
> "
> *** CID 1583619:  Uninitialized variables  (UNINIT)
> sound/virtio/virtio_kctl.c:294 in virtsnd_kctl_tlv_op()
> 288
> 289         break;
> 290       }
> 291
> 292       kfree(tlv);
> 293
> vvv     CID 1583619:  Uninitialized variables  (UNINIT)
> vvv     Using uninitialized value "rc".
> 294       return rc;
> 295     }
> 296
> 297     /**
> 298      * virtsnd_kctl_get_enum_items() - Query items for the ENUMERATED element type.
> 299      * @snd: VirtIO sound device.
> "
> 
> Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
> Signed-off-by: Aiswarya Cyriac <aiswarya.cyriac@opensynergy.com>
> Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
> Addresses-Coverity-ID: 1583619 ("Uninitialized variables")
> Fixes: d6568e3de42d ("ALSA: virtio: add support for audio controls")

Thanks, applied.


Takashi

Re: [PATCH] ALSA: virtio: Fix "Coverity: virtsnd_kctl_tlv_op(): Uninitialized variables" warning.

Posted by Michael S. Tsirkin 1 year, 10 months ago

On Tue, Feb 13, 2024 at 10:02:24AM +0100, Takashi Iwai wrote:
> On Tue, 13 Feb 2024 09:51:30 +0100,
> Aiswarya Cyriac wrote:
> > 
> > Fix the following warning when building virtio_snd driver.
> > 
> > "
> > *** CID 1583619:  Uninitialized variables  (UNINIT)
> > sound/virtio/virtio_kctl.c:294 in virtsnd_kctl_tlv_op()
> > 288
> > 289         break;
> > 290       }
> > 291
> > 292       kfree(tlv);
> > 293
> > vvv     CID 1583619:  Uninitialized variables  (UNINIT)
> > vvv     Using uninitialized value "rc".
> > 294       return rc;
> > 295     }
> > 296
> > 297     /**
> > 298      * virtsnd_kctl_get_enum_items() - Query items for the ENUMERATED element type.
> > 299      * @snd: VirtIO sound device.
> > "
> > 
> > Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
> > Signed-off-by: Aiswarya Cyriac <aiswarya.cyriac@opensynergy.com>
> > Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
> > Addresses-Coverity-ID: 1583619 ("Uninitialized variables")
> > Fixes: d6568e3de42d ("ALSA: virtio: add support for audio controls")
> 
> Thanks, applied.
> 
> 
> Takashi

Why did you apply it directly? The patch isn't great IMHO.
Why not give people a couple of days to review?

-- 
MST

Re: [PATCH] ALSA: virtio: Fix "Coverity: virtsnd_kctl_tlv_op(): Uninitialized variables" warning.

Posted by Takashi Iwai 1 year, 10 months ago

On Tue, 13 Feb 2024 10:07:35 +0100,
Michael S. Tsirkin wrote:
> 
> On Tue, Feb 13, 2024 at 10:02:24AM +0100, Takashi Iwai wrote:
> > On Tue, 13 Feb 2024 09:51:30 +0100,
> > Aiswarya Cyriac wrote:
> > > 
> > > Fix the following warning when building virtio_snd driver.
> > > 
> > > "
> > > *** CID 1583619:  Uninitialized variables  (UNINIT)
> > > sound/virtio/virtio_kctl.c:294 in virtsnd_kctl_tlv_op()
> > > 288
> > > 289         break;
> > > 290       }
> > > 291
> > > 292       kfree(tlv);
> > > 293
> > > vvv     CID 1583619:  Uninitialized variables  (UNINIT)
> > > vvv     Using uninitialized value "rc".
> > > 294       return rc;
> > > 295     }
> > > 296
> > > 297     /**
> > > 298      * virtsnd_kctl_get_enum_items() - Query items for the ENUMERATED element type.
> > > 299      * @snd: VirtIO sound device.
> > > "
> > > 
> > > Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
> > > Signed-off-by: Aiswarya Cyriac <aiswarya.cyriac@opensynergy.com>
> > > Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
> > > Addresses-Coverity-ID: 1583619 ("Uninitialized variables")
> > > Fixes: d6568e3de42d ("ALSA: virtio: add support for audio controls")
> > 
> > Thanks, applied.
> > 
> > 
> > Takashi
> 
> Why did you apply it directly? The patch isn't great IMHO.
> Why not give people a couple of days to review?

Sure, we can wait.  I applied it quickly just since it's an obvious
fix and you haven't responded to the original patch over a month.


thanks,

Takashi