Re: [PATCH] dmaengine: ste_dma40: fix out-of-bounds access from D40_MEMCPY_MAX_CHANS

[Rosen Penev]

On Tue, Jun 2, 2026 at 1:48 AM Linus Walleij <linusw@xxxxxxxxxx> wrote:
>
> On Sun, May 31, 2026 at 11:08 PM Rosen Penev <rosenp@xxxxxxxxx> wrote:
>
> > D40_MEMCPY_MAX_CHANS is defined as 8, but the dma40_memcpy_channels[]
> > array only has 6 elements. This mismatch causes an out-of-bounds
> > issue:
> >
> > 1. d40_of_probe() accepts up to 8 memcpy channels from DT
> >    (num_memcpy > D40_MEMCPY_MAX_CHANS allows 7-8), then writes them
> >    into the 6-element dma40_memcpy_channels[], corrupting adjacent
> >    stack memory.
> >
> > Fix by defining D40_MEMCPY_MAX_CHANS as 6 to match the array size.
> >
> > Fixes: a7dacb68b35a ("dmaengine: ste_dma40: Allow memcpy channels to be configured from DT")
> > Assisted-by: Opencode:Big-Pickle
> > Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx>
>
> Excellent find Rosen!
All credit is to our robot overl-i mean sashiko. I'm under the
impression nothing can get merged unless it's happy.
> Reviewed-by: Linus Walleij <linusw@xxxxxxxxxx>
>
> Yours,
> Linus Walleij