Re: Patch "rust: dma: use pointer projection infra for `dma_{read,write}` macro" has been added to the 6.19-stable tree

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Mar 16, 2026 at 05:19:25PM +0100, Danilo Krummrich wrote:
> On Mon Mar 16, 2026 at 3:00 PM CET, Greg KH wrote:
> > On Sun, Mar 15, 2026 at 02:48:52PM +0000, Gary Guo wrote:
> >> On Sun Mar 15, 2026 at 2:40 PM GMT, Sasha Levin wrote:
> >> > This is a note to let you know that I've just added the patch titled
> >> >
> >> >     rust: dma: use pointer projection infra for `dma_{read,write}` macro
> >> >
> >> > to the 6.19-stable tree which can be found at:
> >> >     http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
> >> >
> >> > The filename of the patch is:
> >> >      rust-dma-use-pointer-projection-infra-for-dma_-read-.patch
> >> > and it can be found in the queue-6.19 subdirectory.
> >> 
> >> Hi Sasha,
> >> 
> >> commit 08da98f18f4f ("rust: ptr: add `KnownSize` trait to support DST size info
> >> extraction") and commit f41941aab3ac ("rust: ptr: add projection
> >> infrastructure") are dependencies of this fix.
> >> 
> >> It doesn't look like these commits are currently being picked. They're needed
> >> for building.
> >> 
> >> They're part of the same series: https://lore.kernel.org/rust-for-linux/20260302164239.284084-1-gary@kernel.org/
> >
> > Yeah, this breaks the build on my systems.  I'll go drop this patch for
> > now, and if you want these in the stable trees, can you provide a
> > backported series of them?
> 
> The DMA soundness fix, as a potential bug, is probably not crucial to backport.
> 
> There are two nova-core fixes on top of it. One of them fixes a UB condition
> reading from and writing to a DMA buffer, the other one is a potential stack
> overflow.
> 
> nova-core is still work in progress, so I'm not too worried about this as far as
> stable trees are concerned.
> 
> I think we usually backport soundness fixes anyway, plus everything should apply
> without conflicts, so it probably doesn't hurt to pick them up regardless.
> 
> I can send a separate series if preferred.

I've dropped all the nova-core patches from the queue as well.  If you
think they are needed in 6.19.y, please send backports.

thanks,

greg k-h