From: Jiri Slaby <jslaby@suse.cz>
Date: Mon, 21 Jun 2010 15:03:21 +0000 (+0200)
Subject: ALSA: usb/endpoint, fix dangling pointer use
X-Git-Tag: firefly_0821_release~9833^2~1428^2^2~1
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=272cbc98cfbdd30cff37a35f8ad8f1b737288e88;p=firefly-linux-kernel-4.4.55.git

ALSA: usb/endpoint, fix dangling pointer use

Stanse found that in snd_usb_parse_audio_endpoints, there is a
dangling pointer dereference. When snd_usb_parse_audio_format fails,
fp is freed, and continue invoked. On the next loop, there is
"fp && fp->altsetting == 1 && fp->channels == 1" test, but fp is set
from the last iteration (but is bogus) and thus ilegally dereferenced.

Set fp to NULL before "continue".

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Daniel Mack <daniel@caiaq.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---

diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 9593b91452b9..6f6596cf2b19 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -427,6 +427,7 @@ int snd_usb_parse_audio_endpoints(struct snd_usb_audio *chip, int iface_no)
 		if (snd_usb_parse_audio_format(chip, fp, format, fmt, stream, alts) < 0) {
 			kfree(fp->rate_table);
 			kfree(fp);
+			fp = NULL;
 			continue;
 		}