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authorClemens Ladisch <clemens@ladisch.de>2011-10-16 01:19:25 +0400
committerTakashi Iwai <tiwai@suse.de>2011-11-06 14:21:42 +0400
commit862a6244eb9f9f5123fe819454fcfcae0ee1f2f9 (patch)
treec2b1afb1818dd722c7026ebd0047972a32845d20 /sound/usb/misc
parent6bcbf64ace40d6833622d85701218a8bb7a4f207 (diff)
downloadlinux-862a6244eb9f9f5123fe819454fcfcae0ee1f2f9.tar.xz
ALSA: ua101: fix crash when unplugging
If the device is unplugged while running, it is possible for a PCM device to be closed after the disconnect callback has returned. This means that kill_stream_urb() and disable_iso_interface() would try to access already-invalid or freed USB data structures. The function free_usb_related_resources() was intended to prevent this, but forgot to clear the affected variables. Reported-and-tested-by: Olivier Courtay <olivier@courtay.org> Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Cc: 2.6.33+ <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb/misc')
-rw-r--r--sound/usb/misc/ua101.c28
1 files changed, 21 insertions, 7 deletions
diff --git a/sound/usb/misc/ua101.c b/sound/usb/misc/ua101.c
index 67bec7612442..c0609c210303 100644
--- a/sound/usb/misc/ua101.c
+++ b/sound/usb/misc/ua101.c
@@ -459,7 +459,8 @@ static void kill_stream_urbs(struct ua101_stream *stream)
unsigned int i;
for (i = 0; i < stream->queue_length; ++i)
- usb_kill_urb(&stream->urbs[i]->urb);
+ if (stream->urbs[i])
+ usb_kill_urb(&stream->urbs[i]->urb);
}
static int enable_iso_interface(struct ua101 *ua, unsigned int intf_index)
@@ -484,6 +485,9 @@ static void disable_iso_interface(struct ua101 *ua, unsigned int intf_index)
{
struct usb_host_interface *alts;
+ if (!ua->intf[intf_index])
+ return;
+
alts = ua->intf[intf_index]->cur_altsetting;
if (alts->desc.bAlternateSetting != 0) {
int err = usb_set_interface(ua->dev,
@@ -1144,27 +1148,37 @@ static void free_stream_urbs(struct ua101_stream *stream)
{
unsigned int i;
- for (i = 0; i < stream->queue_length; ++i)
+ for (i = 0; i < stream->queue_length; ++i) {
kfree(stream->urbs[i]);
+ stream->urbs[i] = NULL;
+ }
}
static void free_usb_related_resources(struct ua101 *ua,
struct usb_interface *interface)
{
unsigned int i;
+ struct usb_interface *intf;
+ mutex_lock(&ua->mutex);
free_stream_urbs(&ua->capture);
free_stream_urbs(&ua->playback);
+ mutex_unlock(&ua->mutex);
free_stream_buffers(ua, &ua->capture);
free_stream_buffers(ua, &ua->playback);
- for (i = 0; i < ARRAY_SIZE(ua->intf); ++i)
- if (ua->intf[i]) {
- usb_set_intfdata(ua->intf[i], NULL);
- if (ua->intf[i] != interface)
+ for (i = 0; i < ARRAY_SIZE(ua->intf); ++i) {
+ mutex_lock(&ua->mutex);
+ intf = ua->intf[i];
+ ua->intf[i] = NULL;
+ mutex_unlock(&ua->mutex);
+ if (intf) {
+ usb_set_intfdata(intf, NULL);
+ if (intf != interface)
usb_driver_release_interface(&ua101_driver,
- ua->intf[i]);
+ intf);
}
+ }
}
static void ua101_card_free(struct snd_card *card)