Re: [PATCH stable v4.4 1/2] net: stmmac: use correct DMA buffer size in the RX descriptor

From: Greg KH
Date: Tue Dec 17 2019 - 02:51:36 EST


On Mon, Dec 16, 2019 at 09:52:27PM -0800, Aviraj CJ wrote:
> upstream 583e6361414903c5206258a30e5bd88cb03c0254 commit
>
> We always program the maximum DMA buffer size into the receive descriptor,
> although the allocated size may be less. E.g. with the default MTU size
> we allocate only 1536 bytes. If somebody sends us a bigger frame, then
> memory may get corrupted.
>
> Program DMA using exact buffer sizes.
>
> Signed-off-by: Aaro Koskinen <aaro.koskinen@xxxxxxxxx>
> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
> [acj: backport to v4.4 -stable :
> - Modified patch since v4.4 driver has no support for Big endian
> - Skipped the section modifying non-existent functions in dwmac4_descs.c and
> dwxgmac2_descs.c ]
> Signed-off-by: Aviraj CJ <acj@xxxxxxxxx>

I can't take stable patches for an older tree and have it "skip" newer
stable trees. To be specific, this patch is already in the 4.19.41
release, but if I were to take it into the 4.4.y tree, then anyone
upgrading to 4.9.y or 4.14.y afterward would run into the same issue.

So can you also send backports to 4.9.y and 4.14.y so that I can take
this fix into all trees?

Same for patch 2/2.

thanks,

greg k-h