lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Mon, 14 Nov 2016 11:25:01 +0100
From:   Takashi Iwai <tiwai@...e.de>
To:     Shuah Khan <shuahkhan@...il.com>
Cc:     alsa-devel@...a-project.org, shuahkh@....samsung.com,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: BUG: KASAN: use-after-free in snd_usb_audio_free

On Sat, 12 Nov 2016 00:34:38 +0100,
Shuah Khan wrote:
> 
> Hi Takashi,
> 
> I am seeing the following use-after-free error when I disconnect an
> USB speaker. I saw this on 4.9-rc4 and 4.8.7. There might be race
> condition between the disconnect and pcm close perhaps.

Thanks, this looks like a new discovery.
Could you check whether the patch below works?


Takashi

---
diff --git a/sound/usb/card.c b/sound/usb/card.c
index 9e5276d6dda0..2ddc034673a8 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -315,7 +315,8 @@ static int snd_usb_audio_free(struct snd_usb_audio *chip)
 		snd_usb_endpoint_free(ep);
 
 	mutex_destroy(&chip->mutex);
-	dev_set_drvdata(&chip->dev->dev, NULL);
+	if (!atomic_read(&chip->shutdown))
+		dev_set_drvdata(&chip->dev->dev, NULL);
 	kfree(chip);
 	return 0;
 }

Powered by blists - more mailing lists