Commit 3c4ab49e authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: core: Fix the debugfs removal at snd_card_free()

The commit 2d670ea2 ("ALSA: jack: implement software jack
injection via debugfs") introduced a debugfs root for each sound card
object.  The debugfs entry gets removed at the card removal, too, but
it turned out that debugfs_remove() is called at a wrong place; it's
after the card object gets freed, hence it leads to use-after-free.

Fix it by moving the debugfs_remove() at the right place, the
destructor of the card device.

Fixes: 2d670ea2

 ("ALSA: jack: implement software jack injection via debugfs")
Reported-and-tested-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Link: https://lore.kernel.org/r/161228343605.1150.8862281636043446562@build.alporthouse.com
Link: https://lore.kernel.org/r/20210202225629.1965-1-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 016f94fe
......@@ -487,6 +487,10 @@ static int snd_card_do_free(struct snd_card *card)
dev_warn(card->dev, "unable to free card info\n");
/* Not fatal error */
}
#ifdef CONFIG_SND_DEBUG
debugfs_remove(card->debugfs_root);
card->debugfs_root = NULL;
#endif
if (card->release_completion)
complete(card->release_completion);
kfree(card);
......@@ -537,11 +541,6 @@ int snd_card_free(struct snd_card *card)
/* wait, until all devices are ready for the free operation */
wait_for_completion(&released);
#ifdef CONFIG_SND_DEBUG
debugfs_remove(card->debugfs_root);
card->debugfs_root = NULL;
#endif
return 0;
}
EXPORT_SYMBOL(snd_card_free);
......
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