lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20190712121629.965015417@linuxfoundation.org>
Date:   Fri, 12 Jul 2019 14:18:17 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Guillaume Nault <gnault@...hat.com>,
        Pablo Neira Ayuso <pablo@...filter.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.1 033/138] netfilter: ipv6: nf_defrag: accept duplicate fragments again

[ Upstream commit 8a3dca632538c550930ce8bafa8c906b130d35cf ]

When fixing the skb leak introduced by the conversion to rbtree, I
forgot about the special case of duplicate fragments. The condition
under the 'insert_error' label isn't effective anymore as
nf_ct_frg6_gather() doesn't override the returned value anymore. So
duplicate fragments now get NF_DROP verdict.

To accept duplicate fragments again, handle them specially as soon as
inet_frag_queue_insert() reports them. Return -EINPROGRESS which will
translate to NF_STOLEN verdict, like any accepted fragment. However,
such packets don't carry any new information and aren't queued, so we
just drop them immediately.

Fixes: a0d56cb911ca ("netfilter: ipv6: nf_defrag: fix leakage of unqueued fragments")
Signed-off-by: Guillaume Nault <gnault@...hat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 net/ipv6/netfilter/nf_conntrack_reasm.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/net/ipv6/netfilter/nf_conntrack_reasm.c b/net/ipv6/netfilter/nf_conntrack_reasm.c
index 5b3f65e29b6f..8951de8b568f 100644
--- a/net/ipv6/netfilter/nf_conntrack_reasm.c
+++ b/net/ipv6/netfilter/nf_conntrack_reasm.c
@@ -265,8 +265,14 @@ static int nf_ct_frag6_queue(struct frag_queue *fq, struct sk_buff *skb,
 
 	prev = fq->q.fragments_tail;
 	err = inet_frag_queue_insert(&fq->q, skb, offset, end);
-	if (err)
+	if (err) {
+		if (err == IPFRAG_DUP) {
+			/* No error for duplicates, pretend they got queued. */
+			kfree_skb(skb);
+			return -EINPROGRESS;
+		}
 		goto insert_error;
+	}
 
 	if (dev)
 		fq->iif = dev->ifindex;
@@ -304,8 +310,6 @@ static int nf_ct_frag6_queue(struct frag_queue *fq, struct sk_buff *skb,
 	return -EINPROGRESS;
 
 insert_error:
-	if (err == IPFRAG_DUP)
-		goto err;
 	inet_frag_kill(&fq->q);
 err:
 	skb_dst_drop(skb);
-- 
2.20.1



Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ