diff options
| author | Takashi Iwai <tiwai@suse.de> | 2017-05-24 11:19:45 +0300 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-09-15 20:29:50 +0300 |
| commit | b61880371f6b1c04c447bc3ad340cfccd9174802 (patch) | |
| tree | d49f3d2010ca66a89cc4087f93e01a8e01339f91 /sound/soc/soc-core.c | |
| parent | bcf7e318f3321daba8855a9d0dfde55515d58180 (diff) | |
| download | linux-b61880371f6b1c04c447bc3ad340cfccd9174802.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>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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 6c927ac43876..93b60ecf61ab 100644 --- a/sound/soc/soc-core.c +++ b/sound/soc/soc-core.c @@ -2014,6 +2014,9 @@ 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); @@ -2025,9 +2028,7 @@ 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 */ |