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author | Xiyu Yang <xiyuyang19@fudan.edu.cn> | 2020-04-23 07:54:19 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-04-29 17:31:29 +0300 |
commit | 33bb5a4f25a2c7543141d10ac166599062c2d9d1 (patch) | |
tree | d8f7870c3c4a7e8227e22260e5d08ec8c07003fe /sound | |
parent | ee5a44badde58a33f417960cfae405be1e6a568d (diff) | |
download | linux-33bb5a4f25a2c7543141d10ac166599062c2d9d1.tar.xz |
ALSA: usb-audio: Fix usb audio refcnt leak when getting spdif
commit 59e1947ca09ebd1cae147c08c7c41f3141233c84 upstream.
snd_microii_spdif_default_get() invokes snd_usb_lock_shutdown(), which
increases the refcount of the snd_usb_audio object "chip".
When snd_microii_spdif_default_get() returns, local variable "chip"
becomes invalid, so the refcount should be decreased to keep refcount
balanced.
The reference counting issue happens in several exception handling paths
of snd_microii_spdif_default_get(). When those error scenarios occur
such as usb_ifnum_to_if() returns NULL, the function forgets to decrease
the refcnt increased by snd_usb_lock_shutdown(), causing a refcnt leak.
Fix this issue by jumping to "end" label when those error scenarios
occur.
Fixes: 447d6275f0c2 ("ALSA: usb-audio: Add sanity checks for endpoint accesses")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1587617711-13200-1-git-send-email-xiyuyang19@fudan.edu.cn
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound')
-rw-r--r-- | sound/usb/mixer_quirks.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/sound/usb/mixer_quirks.c b/sound/usb/mixer_quirks.c index 10c6971cf477..983e8a3ebfcf 100644 --- a/sound/usb/mixer_quirks.c +++ b/sound/usb/mixer_quirks.c @@ -1519,11 +1519,15 @@ static int snd_microii_spdif_default_get(struct snd_kcontrol *kcontrol, /* use known values for that card: interface#1 altsetting#1 */ iface = usb_ifnum_to_if(chip->dev, 1); - if (!iface || iface->num_altsetting < 2) - return -EINVAL; + if (!iface || iface->num_altsetting < 2) { + err = -EINVAL; + goto end; + } alts = &iface->altsetting[1]; - if (get_iface_desc(alts)->bNumEndpoints < 1) - return -EINVAL; + if (get_iface_desc(alts)->bNumEndpoints < 1) { + err = -EINVAL; + goto end; + } ep = get_endpoint(alts, 0)->bEndpointAddress; err = snd_usb_ctl_msg(chip->dev, |