[PATCH net-next] net: ethtool: phy: Check the req_info.pdn field for GET commands

[Eric Dumazet]

On Tue, Sep 10, 2024 at 7:46 PM Maxime Chevallier
<maxime.chevallier at bootlin.com> wrote:
>
> When processing the netlink GET requests to get PHY info, the req_info.pdn
> pointer is NULL when no PHY matches the requested parameters, such as when
> the phy_index is invalid, or there's simply no PHY attached to the
> interface.
>
> Therefore, check the req_info.pdn pointer for NULL instead of
> dereferencing it.
>
> Suggested-by: Eric Dumazet <edumazet at google.com>
> Reported-by: Eric Dumazet <edumazet at google.com>
> Closes: https://lore.kernel.org/netdev/CANn89iKRW0WpGAh1tKqY345D8WkYCPm3Y9ym--Si42JZrQAu1g@mail.gmail.com/T/#mfced87d607d18ea32b3b4934dfa18d7b36669285
> Fixes: 17194be4c8e1 ("net: ethtool: Introduce a command to list PHYs on an interface")
> Signed-off-by: Maxime Chevallier <maxime.chevallier at bootlin.com>
> ---

Thanks, there is another issue found by syzbot BTW (one imbalanced netdev_put())

Reviewed-by: Eric Dumazet <edumazet at google.com>