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ALSA: hda - Handle kzalloc() failure in snd_hda_attach_pcm_stream()

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commit a3aa60d511746bd6c0d0366d4eb90a7998bcde8b upstream.

When 'kzalloc()' fails in 'snd_hda_attach_pcm_stream()', a new pcm instance is
created without setting its operators via 'snd_pcm_set_ops()'. Following
operations on the new pcm instance can trigger kernel null pointer dereferences
and cause kernel oops.

This bug was found with my work on building a gray-box fault-injection tool for
linux-kernel-module binaries. A kernel null pointer dereference was confirmed
from line 'substream->ops->open()' in function 'snd_pcm_open_substream()' in
file 'sound/core/pcm_native.c'.

This patch fixes the bug by calling 'snd_device_free()' in the error handling
path of 'kzalloc()', which removes the new pcm instance from the snd card before
returns with an error code.

Signed-off-by: Bo Chen <chenbo@pdx.edu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Bo Chen 2018-05-31 15:35:18 -07:00 • committed by Greg Kroah-Hartman
parent d85feb4259
commit 9f1592e4a0
1 changed files with 3 additions and 1 deletions
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4
sound/pci/hda/hda_controller.c
View file

@ -547,8 +547,10 @@ int snd_hda_attach_pcm_stream(struct hda_bus *_bus, struct hda_codec *codec,
return err;
strlcpy(pcm->name, cpcm->name, sizeof(pcm->name));
apcm = kzalloc(sizeof(*apcm), GFP_KERNEL);
if (apcm == NULL)
if (apcm == NULL) {
snd_device_free(chip->card, pcm);
return -ENOMEM;
}
apcm->chip = chip;
apcm->pcm = pcm;
apcm->codec = codec;