Re: [PATCH net] net: stmmac: free an skb first when there are no longer any descriptors using it

From: David Miller
Date: Tue Jun 20 2017 - 15:41:33 EST


From: Niklas Cassel <niklas.cassel@xxxxxxxx>
Date: Tue, 20 Jun 2017 14:32:41 +0200

> When having the skb pointer in the first descriptor, stmmac_tx_clean
> can get called at a moment where the IP has only cleared the own bit
> of the first descriptor, thus freeing the skb, even though there can
> be several descriptors whose buffers point into the same skb.
>
> By simply moving the skb pointer from the first descriptor to the last
> descriptor, a skb will get freed only when the IP has cleared the
> own bit of all the descriptors that are using that skb.
>
> Signed-off-by: Niklas Cassel <niklas.cassel@xxxxxxxx>

Applied and queued up for -stable, thanks.