Re: [PATCH] net/sched: act_csum: skip malformed IPv4 headers

[Jakub Kicinski]

On Fri,  5 Jun 2026 15:29:15 +0000 Samuel Moelius wrote:
> act_csum trusts the IPv4 IHL field before using it to locate transport
> header fields.  Packets with an invalid short IHL can make the action
> write checksum data into the IPv4 header instead of the intended L4
> header.
> 
> The action should not repair or modify packets whose IPv4 header length
> is invalid.  Treat those packets as not eligible for checksum repair and
> leave the configured action result unchanged.

I could be wrong but I think we were trying to prevent such packets
from getting in rather than fix all the places that call ip_hdr()?
Someone please correct me if I'm wrong, or ack this, otherwise I'll
toss this patch..
-- 
pw-bot: reject