Re: [PATCH] net: sparx5/lan969x: do not read past skb->len when injecting a frame
From: Daniel Machon
Date: Wed Oct 21 2026 - 07:30:32 EST
> sparx5_inject() writes the frame to the injection FIFO one 32-bit word
> at a time, and pads frames shorter than 60 bytes with zero words.
>
> Before this patch, the last word is loaded whole even when skb->len is
> not a multiple of four, so 1 to 3 bytes past the end of the frame are
> read. For a frame shorter than 60 bytes those bytes are also
> transmitted, as VLD_BYTES marks the whole last word valid and the
> padding starts at the next word.
>
> Write the trailing bytes from a zeroed word. The number of words written
> and VLD_BYTES are unchanged.
>
> Found by an AI code review agent, and reproduced on lan969x and sparx5
> with register injection: bytes 57 to 59 of a 57 byte frame were not
> zero. With the fix they are zero, and traffic still passes on both
> chips.
>
> Fixes: f3cad2611a77 ("net: sparx5: add hostmode with phylink support")
> Signed-off-by: Daniel Machon <daniel.machon@xxxxxxxxxxxxx>
I somehow forgot to include the target tree. This one goes to net.
/Daniel