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

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commit a3aa60d511 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>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

...

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Bo Chen 2018-05-31 15:35:18 -07:00 • committed by Ben Hutchings

parent e9c925215d

commit 9664b50228

1 changed files with 3 additions and 1 deletions

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sound/pci/hda/hda_controller.c

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