Re: [PATCH net v4 1/2] net: sched: act_connmark: initialize struct tc_ife to fix kernel leak

[Eric Dumazet]

On Sun, Nov 9, 2025 at 1:13 AM Ranganath V N <vnranganath.20@xxxxxxxxx> wrote:
>
> In tcf_connmark_dump(), the variable 'opt' was partially initialized using a
> designatied initializer. While the padding bytes are reamined
> uninitialized. nla_put() copies the entire structure into a
> netlink message, these uninitialized bytes leaked to userspace.
>
> Initialize the structure with memset before assigning its fields
> to ensure all members and padding are cleared prior to beign copied.
>
> Reported-by: syzbot+0c85cae3350b7d486aee@xxxxxxxxxxxxxxxxxxxxxxxxx
> Closes: https://syzkaller.appspot.com/bug?extid=0c85cae3350b7d486aee
> Tested-by: syzbot+0c85cae3350b7d486aee@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: 22a5dc0e5e3e ("net: sched: Introduce connmark action")
> Signed-off-by: Ranganath V N <vnranganath.20@xxxxxxxxx>
> ---

Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>