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| author | Bo Chen <chenbo@pdx.edu> | 2018-05-31 15:35:18 -0700 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2018-06-01 09:38:54 +0200 |
| commit | a3aa60d511746bd6c0d0366d4eb90a7998bcde8b (patch) | |
| tree | c680e0958aa6bee4408fdbf26254a284ba683748 /sound | |
| parent | 9ee92f5355f8264de20c8337823aff918c717aee (diff) | |
| download | lwn-a3aa60d511746bd6c0d0366d4eb90a7998bcde8b.tar.gz lwn-a3aa60d511746bd6c0d0366d4eb90a7998bcde8b.zip | |
ALSA: hda - Handle kzalloc() failure in snd_hda_attach_pcm_stream()
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>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/pci/hda/hda_controller.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/sound/pci/hda/hda_controller.c b/sound/pci/hda/hda_controller.c index d1eb14842340..a12e594d4e3b 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; |