From: Stephen Hemminger <stephen@networkplumber.org>
To: Konstantin Ananyev <konstantin.ananyev@huawei.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: DPDK ip_frag security analyis
Date: Thu, 9 Apr 2026 13:10:44 -0700 [thread overview]
Message-ID: <20260409131044.242b8b2d@phoenix.local> (raw)
In-Reply-To: <282c899d27cb40b292d199c7490f3ede@huawei.com>
On Thu, 9 Apr 2026 13:04:52 +0000
Konstantin Ananyev <konstantin.ananyev@huawei.com> wrote:
> > Fix: use TAILQ_FOREACH_SAFE, or save TAILQ_NEXT(fp, lru) before
> > calling ip_frag_tbl_del().
>
> ACK, that looks like a valid one to me.
I sent patch for that one:
https://patchwork.dpdk.org/project/dpdk/patch/20260408161947.285185-2-stephen@networkplumber.org/
> > 6. Hash collision DoS via fixed seed
> >
> > Both ipv4_frag_hash() and ipv6_frag_hash() use CRC32 (x86/ARM)
> > or jhash with a fixed, publicly known prime seed (0xeaad8405).
> > An attacker who can send crafted IP fragments can precompute hash
> > collisions, causing all fragments to land in the same bucket.
> > After bucket_entries concurrent flows collide, new flows are
> > dropped.
> >
> > Fix: randomize the hash seed at table creation time.
>
> ACK, seems valid - needs to be fixed.
Sent patch for that one:
https://patchwork.dpdk.org/project/dpdk/patch/20260408161947.285185-3-stephen@networkplumber.org/
Probably should go to a better hash function to be really paranoid.
Linux and BSD switched over to siphash because of this.
prev parent reply other threads:[~2026-04-09 20:10 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20260407172750.34e1aaf0@phoenix.local>
2026-04-09 13:04 ` DPDK ip_frag security analyis Konstantin Ananyev
2026-04-09 20:10 ` Stephen Hemminger [this message]
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