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[34.85.207.234]) by smtp.gmail.com with ESMTPSA id 00721157ae682-84ca68c1b14sm13427547b3.21.2026.08.22.11.41.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 22 Aug 2026 11:41:35 -0700 (PDT) Date: Sat, 22 Aug 2026 14:41:34 -0400 From: Willem de Bruijn To: Alice Mikityanska , Willem de Bruijn , David Ahern , Ido Schimmel , Jakub Kicinski , Paolo Abeni Cc: "David S. Miller" , Eric Dumazet , Simon Horman , Shuah Khan , Hannes Frederic Sowa , Vadim Fedorenko , netdev@vger.kernel.org, Alice Mikityanska Message-ID: In-Reply-To: <20260822115717.1161782-5-alice.kernel@fastmail.im> References: <20260822115717.1161782-1-alice.kernel@fastmail.im> <20260822115717.1161782-5-alice.kernel@fastmail.im> Subject: Re: [PATCH net v3 4/4] net: ipv6: Clamp to IP6_MAX_MTU in ip6_dst_mtu_maybe_forward Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Alice Mikityanska wrote: > From: Alice Mikityanska > > Commit 427faee167bc ("net: ipv6: introduce ip6_dst_mtu_maybe_forward") > dropped the IP6_MAX_MTU clamp that used to be present in ip6_mtu(). A > similar IPv4 commit ac6627a28dbf ("net: ipv4: Consolidate ipv4_mtu and > ip_dst_mtu_maybe_forward") preserves the IP_MAX_MTU clamp. > > Restore the upper bound in the IPv6 flow to avoid potential 16-bit > overflows in forwarding paths. > > Fixes: 427faee167bc ("net: ipv6: introduce ip6_dst_mtu_maybe_forward") > Signed-off-by: Alice Mikityanska > Suggested-by: Willem de Bruijn Reviewed-by: Willem de Bruijn