| From | Kamal Mostafa <> | Subject | [PATCH 4.2.y-ckt 166/268] ALSA: control: Avoid kernel warnings from tlv ioctl with numid 0 | Date | Wed, 27 Jan 2016 12:33:47 -0800 |
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4.2.8-ckt3 -stable review patch. If anyone has any objections, please let me know.
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From: Takashi Iwai <tiwai@suse.de>
commit c0bcdbdff3ff73a54161fca3cb8b6cdbd0bb8762 upstream.
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> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- sound/core/control.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/sound/core/control.c b/sound/core/control.c index 196a6fe..a85d455 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) { -- 1.9.1
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