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From: Johan Hovold <johan@kernel.org>
To: Takashi Iwai <tiwai@suse.de>
Cc: alsa-devel@alsa-project.org, Johan Hovold <johan@kernel.org>,
	linux-kernel@vger.kernel.org, stable <stable@vger.kernel.org>
Subject: [alsa-devel] [PATCH] ALSA: usb-audio: fix set_format altsetting sanity check
Date: Fri, 20 Dec 2019 10:31:34 +0100	[thread overview]
Message-ID: <20191220093134.1248-1-johan@kernel.org> (raw)

Make sure to check the return value of usb_altnum_to_altsetting() to
avoid dereferencing a NULL pointer when the requested alternate settings
is missing.

The format altsetting number may come from a quirk table and there does
not seem to be any other validation of it (the corresponding index is
checked however).

Fixes: b099b9693d23 ("ALSA: usb-audio: Avoid superfluous usb_set_interface() calls")
Cc: stable <stable@vger.kernel.org>     # 4.18
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 sound/usb/pcm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 9c8930bb00c8..73dd9d21bb42 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -506,9 +506,9 @@ static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
 	if (WARN_ON(!iface))
 		return -EINVAL;
 	alts = usb_altnum_to_altsetting(iface, fmt->altsetting);
-	altsd = get_iface_desc(alts);
-	if (WARN_ON(altsd->bAlternateSetting != fmt->altsetting))
+	if (WARN_ON(!alts))
 		return -EINVAL;
+	altsd = get_iface_desc(alts);
 
 	if (fmt == subs->cur_audiofmt)
 		return 0;
-- 
2.24.1

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WARNING: multiple messages have this Message-ID (diff)
From: Johan Hovold <johan@kernel.org>
To: Takashi Iwai <tiwai@suse.de>
Cc: Jaroslav Kysela <perex@perex.cz>,
	alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org,
	Johan Hovold <johan@kernel.org>, stable <stable@vger.kernel.org>
Subject: [PATCH] ALSA: usb-audio: fix set_format altsetting sanity check
Date: Fri, 20 Dec 2019 10:31:34 +0100	[thread overview]
Message-ID: <20191220093134.1248-1-johan@kernel.org> (raw)

Make sure to check the return value of usb_altnum_to_altsetting() to
avoid dereferencing a NULL pointer when the requested alternate settings
is missing.

The format altsetting number may come from a quirk table and there does
not seem to be any other validation of it (the corresponding index is
checked however).

Fixes: b099b9693d23 ("ALSA: usb-audio: Avoid superfluous usb_set_interface() calls")
Cc: stable <stable@vger.kernel.org>     # 4.18
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 sound/usb/pcm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 9c8930bb00c8..73dd9d21bb42 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -506,9 +506,9 @@ static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt)
 	if (WARN_ON(!iface))
 		return -EINVAL;
 	alts = usb_altnum_to_altsetting(iface, fmt->altsetting);
-	altsd = get_iface_desc(alts);
-	if (WARN_ON(altsd->bAlternateSetting != fmt->altsetting))
+	if (WARN_ON(!alts))
 		return -EINVAL;
+	altsd = get_iface_desc(alts);
 
 	if (fmt == subs->cur_audiofmt)
 		return 0;
-- 
2.24.1


             reply	other threads:[~2019-12-20  9:33 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-20  9:31 Johan Hovold [this message]
2019-12-20  9:31 ` [PATCH] ALSA: usb-audio: fix set_format altsetting sanity check Johan Hovold
2019-12-20  9:46 ` [alsa-devel] " Takashi Iwai
2019-12-20  9:46   ` Takashi Iwai
2019-12-20 10:23   ` [alsa-devel] " Johan Hovold
2019-12-20 10:23     ` Johan Hovold
2019-12-20 10:32     ` [alsa-devel] " Takashi Iwai
2019-12-20 10:32       ` Takashi Iwai

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