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| author | Takashi Iwai <tiwai@suse.de> | 2017-05-24 11:19:45 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-06-14 16:06:04 +0300 |
| commit | eb8fa317cb0184f5179e29bab8c62a4a4087cd4a (patch) | |
| tree | a7e07acfa3b14ff7504c0da19f8d14ac1e976caf /sound/soc/soc-core.c | |
| parent | 82ecd2f054bd778eeb97c775c915b052e2941c79 (diff) | |
| download | linux-eb8fa317cb0184f5179e29bab8c62a4a4087cd4a.tar.xz | |
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/soc/soc-core.c')
| -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 c0bbcd903261..4e3de566809c 100644 --- a/sound/soc/soc-core.c +++ b/sound/soc/soc-core.c @@ -2076,6 +2076,9 @@ static int soc_cleanup_card_resources(struct snd_soc_card *card) list_for_each_entry(rtd, &card->rtd_list, list) flush_delayed_work(&rtd->delayed_work); + /* 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); soc_remove_pcm_runtimes(card); @@ -2090,9 +2093,7 @@ static int soc_cleanup_card_resources(struct snd_soc_card *card) if (card->remove) card->remove(card); - snd_card_free(card->snd_card); return 0; - } /* removes a socdev */ |