Home Home > GIT Browse
diff options
authorBo Chen <chenbo@pdx.edu>2018-05-31 15:35:18 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-06-26 08:08:07 +0800
commit5514389fb21c9d52c636411ce1cd5c5b83905434 (patch)
parent2102637c85a37f2420751a1cc817c01189a61970 (diff)
ALSA: hda - Handle kzalloc() failure in snd_hda_attach_pcm_stream()
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>
1 files changed, 3 insertions, 1 deletions
diff --git a/sound/pci/hda/hda_controller.c b/sound/pci/hda/hda_controller.c
index 0af1132a869e..56af7308a2fd 100644
--- a/sound/pci/hda/hda_controller.c
+++ b/sound/pci/hda/hda_controller.c
@@ -748,8 +748,10 @@ 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;