Commit 272cbc98 authored Jun 21, 2010 by Jiri Slaby Committed by Takashi Iwai Jun 21, 2010

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>

parent 2a383cb3

sound/usb/endpoint.c

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -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) {		if (snd_usb_parse_audio_format(chip, fp, format, fmt, stream, alts) < 0) {
	kfree(fp->rate_table);		kfree(fp->rate_table);
	kfree(fp);		kfree(fp);
			fp = NULL;
	continue;		continue;
	}		}