Re: [PATCH 4.19 38/99] net: stmmac: use correct DMA buffer size in the RX descriptor

[Greg Kroah-Hartman]

On Wed, May 08, 2019 at 09:10:14AM +0900, Nobuhiro Iwamatsu wrote:
> Hi,
> 
> On Mon, May 06, 2019 at 04:32:11PM +0200, Greg Kroah-Hartman wrote:
> > [ Upstream commit 583e6361414903c5206258a30e5bd88cb03c0254 ]
> > 
> > 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.
> > 
> > Fix by using exact buffer sizes.
> > 
> > Signed-off-by: Aaro Koskinen <aaro.koskinen@xxxxxxxxx>
> > Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
> > ---
> >  .../net/ethernet/stmicro/stmmac/descs_com.h   | 22 ++++++++++++-------
> >  .../ethernet/stmicro/stmmac/dwmac4_descs.c    |  2 +-
> >  .../ethernet/stmicro/stmmac/dwxgmac2_descs.c  |  2 +-
> >  .../net/ethernet/stmicro/stmmac/enh_desc.c    | 10 ++++++---
> >  drivers/net/ethernet/stmicro/stmmac/hwif.h    |  2 +-
> >  .../net/ethernet/stmicro/stmmac/norm_desc.c   | 10 ++++++---
> >  .../net/ethernet/stmicro/stmmac/stmmac_main.c |  6 +++--
> 
> This commit is incomplete and we need the following commit:
> 
> commit f87db4dbd52f2f8a170a2b51cb0926221ca7c9e2
> Author: YueHaibing <yuehaibing@xxxxxxxxxx>
> Date:   Wed Apr 17 09:49:39 2019 +0800
> 
>     net: stmmac: Use bfsize1 in ndesc_init_rx_desc
> 
>     gcc warn this:
> 
>     drivers/net/ethernet/stmicro/stmmac/norm_desc.c: In function ndesc_init_rx_desc:
>     drivers/net/ethernet/stmicro/stmmac/norm_desc.c:138:6: warning: variable 'bfsize1' set but not used [-Wunused-but-set-variable]
> 
>     Like enh_desc_init_rx_desc, we should use bfsize1
>     in ndesc_init_rx_desc to calculate 'p->des1'
> 
>     Fixes: 583e63614149 ("net: stmmac: use correct DMA buffer size in the RX descriptor")
>     Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx>
>     Reviewed-by: Aaro Koskinen <aaro.koskinen@xxxxxxxxx>
>     Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
> 
> And this fix is also needed for 5.0.14-rc.
> Please apply this commit to 4.19.y-rc and 5.0.y-rc.

Thanks, now queued up.

greg k-h