From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794046533; b=zKl2JTIq2TIwE6w1YzivGavaFypDhgaqSC5L5kNvdeIGDYm0ggbaH8yVvu58Wqccn4ng Eobw8AV6aujE2bZSD1ejdsSZqn7WOLKauJNBLp2A24ktaNU+PYMz/KJyhnM32SHQ8USZS X1OogS3IkBBclEWuzuejlISdyCCJbIhvYJfbcxLciQLY+npSlQ197fWks9vsjBIJUIZq7 ZDr2OXpqqBSjdDzgEnxmiKXQhOAmTl4Q5Qaj9qqdqIksHFZ7pQhgkGiguM9M0cqNEMZ0t +Ky6VS/2e9CcLCN8mUk62EKNNCSPC2DX417CQecDqYkLA+/xS4CzQyNyhP+mF9vH/2g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794046533; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=oX120kvHTXSxQvN0znzA5+CSEzZ9Xvnqt4g5x0LI3I4=; b=wz8gtxusWy3rq6bN+fEKM4FS0iIJzTWv23xW/+BM5Va2WPTOvUglg/11bzhecgZz/Eim kxspghW1mOLApEbrZR2TQmGdEvxI/pfOAbBPZM7Zp3dviZutIVhiWNdHpvh0NyQ4y0GNt 1bXvjPRk2LcVjR4c7mAMCojNBgFTUjSHtKWGCtuhDb6wLbzUlpd1jUUWOYYIj0VjW9xfk iEZzig0A33j4KJ3cQvtrVGtc4WEVQRolNAyZfqBVSspR6zw/UYIAtA46htwtTVw/j/S5q uQBHqGf2/LCrKVjRdbEITEE1W/LoMlhWvnuMlbCITDAWNyx6J+SpyclqNmqvAROE28A== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=fkpUz9nU; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 21089606D801 for ; Sat, 7 Nov 2026 10:15:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=fkpUz9nU Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D02E1F008A1; Sat, 7 Nov 2026 10:15:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794046533; bh=oX120kvHTXSxQvN0znzA5+CSEzZ9Xvnqt4g5x0LI3I4=; h=From:To:Cc:Subject:Date; b=fkpUz9nULTsc+HFWMRYa5IukrpsxkSR8VgC9FBaPRR3xhkd8OgKJLJOP/m0kG9Oim ypDxdtDAn9zevNou38MpTFEMfREcef+EFmP7JWTf8sQs6FRkgoQE0+miwNm/NvpKYY ODS8MnoQK4ivPAtN/V/uq+6DXc5oLs4wn+XiDLRTZPucLUbgIbO2j1zyPKvwgGeEgE mtcHi9ImbSU8lEqEoBbp10FtwzgezQOZfirdGmSrWWjGTyanqjqHqhpm8CpOCJwQe+ 66UC4YD6hElHBnuiXCKbTbXdPL65XPLXz2hRPmjRTkAe02DyO1Xq2mz0Thl5mXKikR ySYM24z1xN/TQ== From: Sasha Levin To: jeremy.jean@oss.cyber.gouv.fr, edumazet@kernel.org, davem@davem-thinkpadp1gen8.ibmlond.csb Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] inet: frags: prevent acceptance of partially authenticated reassembly" failed to apply to 6.18-stable tree Date: Sat, 7 Nov 2026 05:15:31 -0500 Message-ID: <20261107051531-failed-6.18-6fb4e32f2ce3@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y git checkout FETCH_HEAD git cherry-pick -x 6fb4e32f2ce3234ae0c416872e911706a3484430 # git commit -s git send-email --to '' --in-reply-to '20261107051531-failed-6.18-6fb4e32f2ce3@kernel.org' --subject-prefix 'PATCH 6.18.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 6fb4e32f2ce3234ae0c416872e911706a3484430 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=A9r=C3=A9my=20Jean?= Date: Fri, 23 Oct 2026 18:51:19 +0000 Subject: [PATCH] inet: frags: prevent acceptance of partially authenticated reassembly MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit A reassembled skb retains the secpath from its first fragment, which makes it possible for the final policy check to accept bytes that were not covered by the transform recorded on the skb. This can affect IPsec tunnel traffic, including AH and ESP, and allow a packet to be accepted even though only part of its payload was authenticated. Reject a fragment when its secpath differs from the fragments already in the queue, and keep overlap statistics limited to actual overlaps. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Jérémy Jean Reviewed-by: Eric Dumazet Signed-off-by: Dave Miller --- include/net/inet_frag.h | 1 + include/net/xfrm.h | 17 +++++++++++++++++ net/ipv4/inet_fragment.c | 5 +++++ net/ipv4/ip_fragment.c | 3 ++- net/ipv6/reassembly.c | 3 ++- 5 files changed, 27 insertions(+), 2 deletions(-) diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h index 365925c9d2628..b02d2472b003e 100644 --- a/include/net/inet_frag.h +++ b/include/net/inet_frag.h @@ -171,6 +171,7 @@ extern const u8 ip_frag_ecn_table[16]; #define IPFRAG_OK 0 #define IPFRAG_DUP 1 #define IPFRAG_OVERLAP 2 +#define IPFRAG_MIXED_SECPATH 3 int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb, int offset, int end); void *inet_frag_reasm_prepare(struct inet_frag_queue *q, struct sk_buff *skb, diff --git a/include/net/xfrm.h b/include/net/xfrm.h index a6d69aaa6cd2d..298ca9bb00835 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -1201,6 +1201,23 @@ secpath_reset(struct sk_buff *skb) #endif } +static inline bool +secpath_equal(const struct sk_buff *skb1, const struct sk_buff *skb2) +{ + const struct sec_path *sp1 = skb_sec_path(skb1); + const struct sec_path *sp2 = skb_sec_path(skb2); + int i; + + if (!sp1 || !sp2) + return sp1 == sp2; + if (sp1->len != sp2->len) + return false; + for (i = 0; i < sp1->len; i++) + if (sp1->xvec[i] != sp2->xvec[i]) + return false; + return true; +} + static inline int xfrm_addr_any(const xfrm_address_t *addr, unsigned short family) { diff --git a/net/ipv4/inet_fragment.c b/net/ipv4/inet_fragment.c index b286ee429da8f..c18da91c1f031 100644 --- a/net/ipv4/inet_fragment.c +++ b/net/ipv4/inet_fragment.c @@ -23,6 +23,7 @@ #include #include #include +#include /* Use skb->cb to track consecutive/adjacent fragments coming at * the end of the queue. Nodes in the rb-tree queue will @@ -441,6 +442,10 @@ int inet_frag_queue_insert(struct inet_frag_queue *q, struct sk_buff *skb, { struct sk_buff *last = q->fragments_tail; + /* The reassembled skb keeps the first fragment's secpath. */ + if (last && !secpath_equal(last, skb)) + return IPFRAG_MIXED_SECPATH; + /* An IP fragment is never a GSO packet, but an untrusted source * (virtio_net_hdr) may have attached GSO metadata to it. Do not let * that reach the reassembled skb, whose head keeps the first diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c index c790d2f494870..36105dd192823 100644 --- a/net/ipv4/ip_fragment.c +++ b/net/ipv4/ip_fragment.c @@ -378,8 +378,9 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb, int *refs) err = -EINVAL; goto err; } + if (err == IPFRAG_OVERLAP) + __IP_INC_STATS(net, IPSTATS_MIB_REASM_OVERLAPS); err = -EINVAL; - __IP_INC_STATS(net, IPSTATS_MIB_REASM_OVERLAPS); discard_qp: inet_frag_kill(&qp->q, refs); __IP_INC_STATS(net, IPSTATS_MIB_REASMFAILS); diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c index a7964125c764c..8418ed9423f4b 100644 --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -241,8 +241,9 @@ static int ip6_frag_queue(struct net *net, err = -EINVAL; goto err; } + if (err == IPFRAG_OVERLAP) + __IP6_INC_STATS(net, idev, IPSTATS_MIB_REASM_OVERLAPS); err = -EINVAL; - __IP6_INC_STATS(net, idev, IPSTATS_MIB_REASM_OVERLAPS); discard_fq: inet_frag_kill(&fq->q, refs); __IP6_INC_STATS(net, idev, IPSTATS_MIB_REASMFAILS); -- 2.53.0