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| author | Takashi Iwai <tiwai@suse.de> | 2017-05-24 10:19:45 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-06-14 13:16:26 +0200 |
| commit | 9a9388953bdcd416f94991f3bd19ea9bc2b31930 (patch) | |
| tree | e82d26d3fe1ce8a3c06981a964823cce5cdf9d55 | |
| parent | 54d12fbf54d4d40d2a47200150344bc001a29e96 (diff) | |
| download | linux-stable-9a9388953bdcd416f94991f3bd19ea9bc2b31930.tar.gz linux-stable-9a9388953bdcd416f94991f3bd19ea9bc2b31930.tar.bz2 linux-stable-9a9388953bdcd416f94991f3bd19ea9bc2b31930.zip | |
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>
| -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 a1305f827a98..fa6b74a304a7 100644 --- a/sound/soc/soc-core.c +++ b/sound/soc/soc-core.c @@ -1775,6 +1775,9 @@ 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); @@ -1786,9 +1789,7 @@ 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 */ |