On Mon, 19 Jun 2017 09:27:09 +0200, Robert Jarzmik wrote: > > From: Takashi Iwai <tiwai@xxxxxxx> > > 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@xxxxxxx> > Cc: <stable@xxxxxxxxxxxxxxx> > Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> This patch must be superfluous :) Takashi > --- > sound/soc/soc-core.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c > index 2722bb0c5573..98d60f471c5d 100644 > --- a/sound/soc/soc-core.c > +++ b/sound/soc/soc-core.c > @@ -2286,6 +2286,9 @@ 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); > @@ -2300,9 +2303,7 @@ 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 */ > -- > 2.1.4 > >