hello:
       In embedded devices with relatively small memory, if the transfer speed of ncm is fast and other programs occupy CPU memory, it is likely that the return value ncm ->skd_tx_data of alloc_skb() is NULL, and the code is likely to enter err. If skb2 is not processed in err, it will cause memory leakage.

Thank you.
nanfengwq@sina.com
 
From: gregkh
Date: 2024-05-19 22:37
To: nanfengwq@sina.com
CC: balbi; linux-usb; linux-kernel
Subject: Re: memory leakage in ncm_wrap_ntb() in USB ncm mode with kernel 5.15
On Sun, May 19, 2024 at 10:23:10PM +0800, nanfengwq@sina.com wrote:
> Helloļ¼š
> I have discovered a risk of memory leakage in ncm_wrap_ntb() under USB ncm mode in kernel 5.15, and I have fixed it.
> Please help me review it.
>
> If this modification is effective, it can also be integrated into other kernel versions, such as kernel 4.14, and so on.
>
> The logic of a memory leak is as follows:
>
> If the return value skb2 of  package_for_tx() is not NULL, and the return value ncm->skb_tx_data of alloc_skb() is NULL, then the code will go to err, where there is no processing of skb2, resulting in a memory leak in skb2.
>
>
> Thank you.
>
>
>
>
 
 
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