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| author | Vladis Dronov <vdronov@redhat.com> | 2016-03-31 12:05:43 -0400 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2016-07-12 08:47:20 -0400 |
| commit | 9279da1e372119d5a2387d0cb32541267649b5ed (patch) | |
| tree | aa882ba1aa203183e0506f90799acf4ba7a2b035 /sound/usb/quirks.c | |
| parent | 4aaf33222ca629d65ebd91a5b1755f66349d3626 (diff) | |
| download | lwn-9279da1e372119d5a2387d0cb32541267649b5ed.tar.gz lwn-9279da1e372119d5a2387d0cb32541267649b5ed.zip | |
ALSA: usb-audio: Fix double-free in error paths after snd_usb_add_audio_stream() call
[ Upstream commit 836b34a935abc91e13e63053d0a83b24dfb5ea78 ]
create_fixed_stream_quirk(), snd_usb_parse_audio_interface() and
create_uaxx_quirk() functions allocate the audioformat object by themselves
and free it upon error before returning. However, once the object is linked
to a stream, it's freed again in snd_usb_audio_pcm_free(), thus it'll be
double-freed, eventually resulting in a memory corruption.
This patch fixes these failures in the error paths by unlinking the audioformat
object before freeing it.
Based on a patch by Takashi Iwai <tiwai@suse.de>
[Note for stable backports:
this patch requires the commit 902eb7fd1e4a ('ALSA: usb-audio: Minor
code cleanup in create_fixed_stream_quirk()')]
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1283358
Reported-by: Ralf Spenneberg <ralf@spenneberg.net>
Cc: <stable@vger.kernel.org> # see the note above
Signed-off-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'sound/usb/quirks.c')
| -rw-r--r-- | sound/usb/quirks.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c index c6523eb7284e..7a44d07c797d 100644 --- a/sound/usb/quirks.c +++ b/sound/usb/quirks.c @@ -138,6 +138,7 @@ static int create_fixed_stream_quirk(struct snd_usb_audio *chip, usb_audio_err(chip, "cannot memdup\n"); return -ENOMEM; } + INIT_LIST_HEAD(&fp->list); if (fp->nr_rates > MAX_NR_RATES) { kfree(fp); return -EINVAL; @@ -181,6 +182,7 @@ static int create_fixed_stream_quirk(struct snd_usb_audio *chip, return 0; error: + list_del(&fp->list); /* unlink for avoiding double-free */ kfree(fp); kfree(rate_table); return err; @@ -456,6 +458,7 @@ static int create_uaxx_quirk(struct snd_usb_audio *chip, fp->ep_attr = get_endpoint(alts, 0)->bmAttributes; fp->datainterval = 0; fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize); + INIT_LIST_HEAD(&fp->list); switch (fp->maxpacksize) { case 0x120: @@ -479,6 +482,7 @@ static int create_uaxx_quirk(struct snd_usb_audio *chip, ? SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK; err = snd_usb_add_audio_stream(chip, stream, fp); if (err < 0) { + list_del(&fp->list); /* unlink for avoiding double-free */ kfree(fp); return err; } |