Re: [PATCH] net: 8139too: use unaligned helpers when setting MAC address

[Lucas]

Hi Andrew,

After looking into this further, I don't think this warrants a fix for
the net tree. dev->dev_addr is backed by a MAX_ADDR_LEN buffer, so the
second 32-bit read does not actually go out of bounds, and I don't
have a concrete case where the alignment causes a problem.

I'll drop the patch.
Thanks for the review.

Regards,
Lucas


On Mon, Aug 24, 2026 at 4:38 PM Andrew Lunn <andrew@xxxxxxx> wrote:
>
> On Mon, Aug 24, 2026 at 12:37:09PM +0200, Lucas Poupeau wrote:
> > From: Lucas <lucasp.linux@xxxxxxxxx>
> >
> > rtl8139_set_mac_address() accesses dev->dev_addr by casting it to u32
> > pointers. Besides potentially performing unaligned accesses, the second
> > read starts at offset 4 and reads 32 bits even though only two bytes
> > remain in the Ethernet address.
> >
> > Use get_unaligned_le32() and get_unaligned_le16() to read the address
> > with the appropriate width and endianness. This also fixes the Sparse
> > type warnings caused by passing __le32 values to iowrite32().
> >
> > Signed-off-by: Lucas Poupeau <lucasp.linux@xxxxxxxxx>
>
> If you are targeting the net tree, you need a Fixes: tag.
>
> https://www.kernel.org/doc/html/latest/process/maintainer-netdev.html
>
> Does this bother people?
>
> https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
>
>     Andrew
>
> ---
> pw-bot: cr