On Tue, Mar 26, 2019 at 10:35:41AM -0700, Curtis Malainey wrote: > This has already been patched. See > https://mailman.alsa-project.org/pipermail/alsa-devel/2019-March/146150.html Ah, obviously. I missed that one. Sorry for the noise. Guenter > > On Tue, Mar 26, 2019 at 10:23 AM Guenter Roeck <linux@xxxxxxxxxxxx> wrote: > > > > If snd_soc_register_card() fails because one of its links fails > > to instantiate with -EPROBE_DEFER, and the to-be-registered link > > is a legacy link, a subsequent retry will trigger a use-after-free > > and quite often a system crash. > > > > Example: > > > > byt-max98090 byt-max98090: ASoC: failed to init link Baytrail Audio > > byt-max98090 byt-max98090: snd_soc_register_card failed -517 > > .... > > BUG: KASAN: use-after-free in snd_soc_init_platform+0x233/0x312 > > Read of size 8 at addr ffff888067c43070 by task kworker/1:1/23 > > > > snd_soc_init_platform() allocates memory attached to the card device. > > This memory is released when the card device is released. However, > > the pointer to the memory (dai_link->platforms) is only cleared from > > soc_cleanup_platform(), which is called from soc_cleanup_card_resources(), > > but not if snd_soc_register_card() fails early. > > > > Add the missing call to soc_cleanup_platform() in the error handling > > code of snd_soc_register_card() to fix the problem. > > > > Fixes: 78a24e10cd94 ("ASoC: soc-core: clear platform pointers on error") > > Cc: Curtis Malainey <cujomalainey@xxxxxxxxxxxx> > > Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> > > --- > > sound/soc/soc-core.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c > > index 93d316d5bf8e..6bf9884d0863 100644 > > --- a/sound/soc/soc-core.c > > +++ b/sound/soc/soc-core.c > > @@ -2799,6 +2799,7 @@ int snd_soc_register_card(struct snd_soc_card *card) > > if (ret) { > > dev_err(card->dev, "ASoC: failed to init link %s\n", > > link->name); > > + soc_cleanup_platform(card); > > mutex_unlock(&client_mutex); > > return ret; > > } > > -- > > 2.7.4 > > _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
