2016-03-17 02:58:12

by Shuah Khan

Subject: [PATCH] sound/usb: Fix memory leak in media_snd_stream_delete() during unbind

media_snd_stream_delete() fails to release resources during unbind. This
leads to use-after-free in media_gobj_create() on a subsequent bind.

[ 1445.086410] BUG: KASAN: use-after-free in media_gobj_create+0x3a1/0x470 [media] at addr ffff8801ead49998

[ 1445.086771] Call Trace:
[ 1445.086779] [<ffffffff81ade373>] dump_stack+0x67/0x94
[ 1445.086785] [<ffffffff81523c29>] print_trailer+0xf9/0x150
[ 1445.086790] [<ffffffff81529644>] object_err+0x34/0x40
[ 1445.086796] [<ffffffff8152b9e1>] kasan_report_error+0x221/0x530
[ 1445.086803] [<ffffffff8152bfb3>] __asan_report_store8_noabort+0x43/0x50
[ 1445.086813] [<ffffffffa0a79341>] ? media_gobj_create+0x3a1/0x470 [media]
[ 1445.086822] [<ffffffffa0a79341>] media_gobj_create+0x3a1/0x470 [media]
[ 1445.086831] [<ffffffffa0a705a9>] media_device_register_entity+0x259/0x6f0 [media]
[ 1445.086841] [<ffffffffa0a70350>] ? media_device_unregister_entity_notify+0x100/0x100 [media]
[ 1445.086846] [<ffffffff81526232>] ? ___slab_alloc+0x172/0x500
[ 1445.086854] [<ffffffff81203548>] ? mark_held_locks+0xc8/0x120
[ 1445.086859] [<ffffffff81526610>] ? __slab_alloc+0x50/0x70
[ 1445.086878] [<ffffffffa0fe711c>] ? media_snd_mixer_init+0x16c/0x500 [snd_usb_audio]
[ 1445.086884] [<ffffffff8152b086>] ? kasan_unpoison_shadow+0x36/0x50
[ 1445.086890] [<ffffffff8152b086>] ? kasan_unpoison_shadow+0x36/0x50
[ 1445.086895] [<ffffffff8152b0fe>] ? kasan_kmalloc+0x5e/0x70

Signed-off-by: Shuah Khan <[email protected]>
---
sound/usb/media.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/usb/media.c b/sound/usb/media.c
index 44a5de9..0d03773 100644
--- a/sound/usb/media.c
+++ b/sound/usb/media.c
@@ -135,7 +135,7 @@ void media_snd_stream_delete(struct snd_usb_substream *subs)
if (mctl && mctl->media_dev) {
struct media_device *mdev;

- mdev = subs->stream->chip->media_dev;
+ mdev = mctl->media_dev;
if (mdev && media_devnode_is_registered(&mdev->devnode)) {
media_devnode_remove(mctl->intf_devnode);
media_device_unregister_entity(&mctl->media_entity);
--
2.5.0

2016-03-17 03:01:16

by Shuah Khan

Subject: Re: [PATCH] sound/usb: Fix memory leak in media_snd_stream_delete() during unbind

Adding Takashi Iwai

On 03/16/2016 08:58 PM, Shuah Khan wrote:
> media_snd_stream_delete() fails to release resources during unbind. This
> leads to use-after-free in media_gobj_create() on a subsequent bind.
>
> [ 1445.086410] BUG: KASAN: use-after-free in media_gobj_create+0x3a1/0x470 [media] at addr ffff8801ead49998
>
> [ 1445.086771] Call Trace:
> [ 1445.086779] [<ffffffff81ade373>] dump_stack+0x67/0x94
> [ 1445.086785] [<ffffffff81523c29>] print_trailer+0xf9/0x150
> [ 1445.086790] [<ffffffff81529644>] object_err+0x34/0x40
> [ 1445.086796] [<ffffffff8152b9e1>] kasan_report_error+0x221/0x530
> [ 1445.086803] [<ffffffff8152bfb3>] __asan_report_store8_noabort+0x43/0x50
> [ 1445.086813] [<ffffffffa0a79341>] ? media_gobj_create+0x3a1/0x470 [media]
> [ 1445.086822] [<ffffffffa0a79341>] media_gobj_create+0x3a1/0x470 [media]
> [ 1445.086831] [<ffffffffa0a705a9>] media_device_register_entity+0x259/0x6f0 [media]
> [ 1445.086841] [<ffffffffa0a70350>] ? media_device_unregister_entity_notify+0x100/0x100 [media]
> [ 1445.086846] [<ffffffff81526232>] ? ___slab_alloc+0x172/0x500
> [ 1445.086854] [<ffffffff81203548>] ? mark_held_locks+0xc8/0x120
> [ 1445.086859] [<ffffffff81526610>] ? __slab_alloc+0x50/0x70
> [ 1445.086878] [<ffffffffa0fe711c>] ? media_snd_mixer_init+0x16c/0x500 [snd_usb_audio]
> [ 1445.086884] [<ffffffff8152b086>] ? kasan_unpoison_shadow+0x36/0x50
> [ 1445.086890] [<ffffffff8152b086>] ? kasan_unpoison_shadow+0x36/0x50
> [ 1445.086895] [<ffffffff8152b0fe>] ? kasan_kmalloc+0x5e/0x70
>
> Signed-off-by: Shuah Khan <[email protected]>
> ---
> sound/usb/media.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/sound/usb/media.c b/sound/usb/media.c
> index 44a5de9..0d03773 100644
> --- a/sound/usb/media.c
> +++ b/sound/usb/media.c
> @@ -135,7 +135,7 @@ void media_snd_stream_delete(struct snd_usb_substream *subs)
> if (mctl && mctl->media_dev) {
> struct media_device *mdev;
>
> - mdev = subs->stream->chip->media_dev;
> + mdev = mctl->media_dev;
> if (mdev && media_devnode_is_registered(&mdev->devnode)) {
> media_devnode_remove(mctl->intf_devnode);
> media_device_unregister_entity(&mctl->media_entity);
>


--
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
[email protected] | (970) 217-8978

2016-03-17 09:26:58

by Takashi Iwai

Subject: Re: [alsa-devel] [PATCH] sound/usb: Fix memory leak in media_snd_stream_delete() during unbind

On Thu, 17 Mar 2016 03:58:06 +0100,
Shuah Khan wrote:
>
> media_snd_stream_delete() fails to release resources during unbind. This
> leads to use-after-free in media_gobj_create() on a subsequent bind.
>
> [ 1445.086410] BUG: KASAN: use-after-free in media_gobj_create+0x3a1/0x470 [media] at addr ffff8801ead49998
>
> [ 1445.086771] Call Trace:
> [ 1445.086779] [<ffffffff81ade373>] dump_stack+0x67/0x94
> [ 1445.086785] [<ffffffff81523c29>] print_trailer+0xf9/0x150
> [ 1445.086790] [<ffffffff81529644>] object_err+0x34/0x40
> [ 1445.086796] [<ffffffff8152b9e1>] kasan_report_error+0x221/0x530
> [ 1445.086803] [<ffffffff8152bfb3>] __asan_report_store8_noabort+0x43/0x50
> [ 1445.086813] [<ffffffffa0a79341>] ? media_gobj_create+0x3a1/0x470 [media]
> [ 1445.086822] [<ffffffffa0a79341>] media_gobj_create+0x3a1/0x470 [media]
> [ 1445.086831] [<ffffffffa0a705a9>] media_device_register_entity+0x259/0x6f0 [media]
> [ 1445.086841] [<ffffffffa0a70350>] ? media_device_unregister_entity_notify+0x100/0x100 [media]
> [ 1445.086846] [<ffffffff81526232>] ? ___slab_alloc+0x172/0x500
> [ 1445.086854] [<ffffffff81203548>] ? mark_held_locks+0xc8/0x120
> [ 1445.086859] [<ffffffff81526610>] ? __slab_alloc+0x50/0x70
> [ 1445.086878] [<ffffffffa0fe711c>] ? media_snd_mixer_init+0x16c/0x500 [snd_usb_audio]
> [ 1445.086884] [<ffffffff8152b086>] ? kasan_unpoison_shadow+0x36/0x50
> [ 1445.086890] [<ffffffff8152b086>] ? kasan_unpoison_shadow+0x36/0x50
> [ 1445.086895] [<ffffffff8152b0fe>] ? kasan_kmalloc+0x5e/0x70
>
> Signed-off-by: Shuah Khan <[email protected]>

Mauro, please take it through your tree.

Acked-by: Takashi Iwai <[email protected]>


thanks,

Takashi

> ---
> sound/usb/media.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/sound/usb/media.c b/sound/usb/media.c
> index 44a5de9..0d03773 100644
> --- a/sound/usb/media.c
> +++ b/sound/usb/media.c
> @@ -135,7 +135,7 @@ void media_snd_stream_delete(struct snd_usb_substream *subs)
> if (mctl && mctl->media_dev) {
> struct media_device *mdev;
>
> - mdev = subs->stream->chip->media_dev;
> + mdev = mctl->media_dev;
> if (mdev && media_devnode_is_registered(&mdev->devnode)) {
> media_devnode_remove(mctl->intf_devnode);
> media_device_unregister_entity(&mctl->media_entity);
> --
> 2.5.0
>
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