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authorTakashi Iwai <tiwai@suse.de>2016-01-18 14:12:40 +0100
committerTakashi Iwai <tiwai@suse.de>2016-01-18 14:40:07 +0100
commitc0bcdbdff3ff73a54161fca3cb8b6cdbd0bb8762 (patch)
treed8429b3e98516f34c872fc91e2537d2013305e9a /sound/core/control.c
parent9586495dc3011a80602329094e746dbce16cb1f1 (diff)
downloadlinux-c0bcdbdff3ff73a54161fca3cb8b6cdbd0bb8762.tar.gz
ALSA: control: Avoid kernel warnings from tlv ioctl with numid 0
When a TLV ioctl with numid zero is handled, the driver may spew a
kernel warning with a stack trace at each call.  The check was
intended obviously only for a kernel driver, but not for a user
interaction.  Let's fix it.

This was spotted by syzkaller fuzzer.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core/control.c')
-rw-r--r--sound/core/control.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/sound/core/control.c b/sound/core/control.c
index 196a6fe100ca..a85d45595d02 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -1405,6 +1405,8 @@ static int snd_ctl_tlv_ioctl(struct snd_ctl_file *file,
 		return -EFAULT;
 	if (tlv.length < sizeof(unsigned int) * 2)
 		return -EINVAL;
+	if (!tlv.numid)
+		return -EINVAL;
 	down_read(&card->controls_rwsem);
 	kctl = snd_ctl_find_numid(card, tlv.numid);
 	if (kctl == NULL) {