Re: [PATCH 080/190] Revert "ALSA: usx2y: fix a double free bug"

[Takashi Iwai]

On Wed, 21 Apr 2021 14:59:15 +0200,
Greg Kroah-Hartman wrote:
> 
> This reverts commit cbb88db76a1536e02e93e5bd37ebbfbb6c4043a9.
> 
> Commits from @umn.edu addresses have been found to be submitted in "bad
> faith" to try to test the kernel community's ability to review "known
> malicious" changes.  The result of these submissions can be found in a
> paper published at the 42nd IEEE Symposium on Security and Privacy
> entitled, "Open Source Insecurity: Stealthily Introducing
> Vulnerabilities via Hypocrite Commits" written by Qiushi Wu (University
> of Minnesota) and Kangjie Lu (University of Minnesota).
> 
> Because of this, all submissions from this group must be reverted from
> the kernel tree and will need to be re-reviewed again to determine if
> they actually are a valid fix.  Until that work is complete, remove this
> change to ensure that no problems are being introduced into the
> codebase.
> 
> Cc: Wenwen Wang <wang6495@xxxxxxx>
> Cc: Takashi Iwai <tiwai@xxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

I examined the change again, and confirmed that this code change
itself is correct, so it's not necessary to revert.

OTOH, it's just a tip of iceberg in this driver, and maybe it's better
to cover all in a better way.  So it's fine to revert this, either.


thanks,

Takashi

> ---
>  sound/usb/usx2y/usbusx2y.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/sound/usb/usx2y/usbusx2y.c b/sound/usb/usx2y/usbusx2y.c
> index 3cd28d24f0a7..bb188245b0e2 100644
> --- a/sound/usb/usx2y/usbusx2y.c
> +++ b/sound/usb/usx2y/usbusx2y.c
> @@ -279,8 +279,10 @@ int usX2Y_In04_init(struct usX2Ydev *usX2Y)
>  	if (! (usX2Y->In04urb = usb_alloc_urb(0, GFP_KERNEL)))
>  		return -ENOMEM;
>  
> -	if (! (usX2Y->In04Buf = kmalloc(21, GFP_KERNEL)))
> +	if (! (usX2Y->In04Buf = kmalloc(21, GFP_KERNEL))) {
> +		usb_free_urb(usX2Y->In04urb);
>  		return -ENOMEM;
> +	}
>  	 
>  	init_waitqueue_head(&usX2Y->In04WaitQueue);
>  	usb_fill_int_urb(usX2Y->In04urb, usX2Y->dev, usb_rcvintpipe(usX2Y->dev, 0x4),
> -- 
> 2.31.1
>