diff options
author | Takashi Iwai <tiwai@suse.de> | 2017-05-24 10:19:45 +0200 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-06-14 12:54:20 +0200 |
commit | 96f81ced46b3742300682808708506b6ce8551b2 (patch) | |
tree | c55a4776975171b5fafa89a36c3ce76ab4d1ad63 /sound | |
parent | 69413811d2536f8ad626cc9537d34dd39133ebab (diff) |
ASoC: Fix use-after-free at card unregistration
commit 4efda5f2130da033aeedc5b3205569893b910de2 upstream.
soc_cleanup_card_resources() call snd_card_free() at the last of its
procedure. This turned out to lead to a use-after-free.
PCM runtimes have been already removed via soc_remove_pcm_runtimes(),
while it's dereferenced later in soc_pcm_free() called via
snd_card_free().
The fix is simple: just move the snd_card_free() call to the beginning
of the whole procedure. This also gives another benefit: it
guarantees that all operations have been shut down before actually
releasing the resources, which was racy until now.
Reported-and-tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound')
-rw-r--r-- | sound/soc/soc-core.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c index b60ff56ebc0f..8bae8e49e403 100644 --- a/sound/soc/soc-core.c +++ b/sound/soc/soc-core.c @@ -1868,6 +1868,9 @@ static int soc_cleanup_card_resources(struct snd_soc_card *card) for (i = 0; i < card->num_aux_devs; i++) soc_remove_aux_dev(card, i); + /* free the ALSA card at first; this syncs with pending operations */ + snd_card_free(card->snd_card); + /* remove and free each DAI */ soc_remove_dai_links(card); @@ -1879,9 +1882,7 @@ static int soc_cleanup_card_resources(struct snd_soc_card *card) snd_soc_dapm_free(&card->dapm); - snd_card_free(card->snd_card); return 0; - } /* removes a socdev */ |