From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: [NETFILTER -stable 01/03]: nfnetlink_queue: fix SKB_LINEAR_ASSERT when mangling packet data Date: Mon, 25 Feb 2008 15:01:01 +0100 (MET) Message-ID: <20080225140059.20602.57007.sendpatchset@localhost.localdomain> References: <20080225140058.20602.52127.sendpatchset@localhost.localdomain> Cc: Patrick McHardy , netfilter-devel@vger.kernel.org, davem@davemloft.net To: stable@kernel.org Return-path: Received: from stinky.trash.net ([213.144.137.162]:50665 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751498AbYBYOBF (ORCPT ); Mon, 25 Feb 2008 09:01:05 -0500 In-Reply-To: <20080225140058.20602.52127.sendpatchset@localhost.localdomain> Sender: netfilter-devel-owner@vger.kernel.org List-ID: [NETFILTER]: nfnetlink_queue: fix SKB_LINEAR_ASSERT when mangling packet data Upstream commit e2b58a67: As reported by Tomas Simonaitis , inserting new data in skbs queued over {ip,ip6,nfnetlink}_queue triggers a SKB_LINEAR_ASSERT in skb_put(). Going back through the git history, it seems this bug is present since at least 2.6.12-rc2, probably even since the removal of skb_linearize() for netfilter. Linearize non-linear skbs through skb_copy_expand() when enlarging them. Tested by Thomas, fixes bugzilla #9933. Signed-off-by: Patrick McHardy --- commit 2e1a9528d31fda88923d6615eb4933df07f59762 tree 46cc8d288a33e945bec29f529a8f56d47c1b37bd parent c78cb439103bf7deba5feb64921398d0ff93179a author Patrick McHardy Mon, 25 Feb 2008 14:51:16 +0100 committer Patrick McHardy Mon, 25 Feb 2008 14:51:16 +0100 net/ipv4/netfilter/ip_queue.c | 12 +++++++----- net/ipv6/netfilter/ip6_queue.c | 10 ++++++---- net/netfilter/nfnetlink_queue.c | 10 ++++++---- 3 files changed, 19 insertions(+), 13 deletions(-) diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c index 14d64a3..16d0fb3 100644 --- a/net/ipv4/netfilter/ip_queue.c +++ b/net/ipv4/netfilter/ip_queue.c @@ -336,8 +336,8 @@ static int ipq_mangle_ipv4(ipq_verdict_msg_t *v, struct ipq_queue_entry *e) { int diff; - int err; struct iphdr *user_iph = (struct iphdr *)v->payload; + struct sk_buff *nskb; if (v->data_len < sizeof(*user_iph)) return 0; @@ -349,14 +349,16 @@ ipq_mangle_ipv4(ipq_verdict_msg_t *v, struct ipq_queue_entry *e) if (v->data_len > 0xFFFF) return -EINVAL; if (diff > skb_tailroom(e->skb)) { - err = pskb_expand_head(e->skb, 0, + nskb = skb_copy_expand(e->skb, 0, diff - skb_tailroom(e->skb), GFP_ATOMIC); - if (err) { + if (!nskb) { printk(KERN_WARNING "ip_queue: error " - "in mangle, dropping packet: %d\n", -err); - return err; + "in mangle, dropping packet\n"); + return -ENOMEM; } + kfree_skb(e->skb); + e->skb = nskb; } skb_put(e->skb, diff); } diff --git a/net/ipv6/netfilter/ip6_queue.c b/net/ipv6/netfilter/ip6_queue.c index e273605..710a04f 100644 --- a/net/ipv6/netfilter/ip6_queue.c +++ b/net/ipv6/netfilter/ip6_queue.c @@ -333,8 +333,8 @@ static int ipq_mangle_ipv6(ipq_verdict_msg_t *v, struct ipq_queue_entry *e) { int diff; - int err; struct ipv6hdr *user_iph = (struct ipv6hdr *)v->payload; + struct sk_buff *nskb; if (v->data_len < sizeof(*user_iph)) return 0; @@ -346,14 +346,16 @@ ipq_mangle_ipv6(ipq_verdict_msg_t *v, struct ipq_queue_entry *e) if (v->data_len > 0xFFFF) return -EINVAL; if (diff > skb_tailroom(e->skb)) { - err = pskb_expand_head(e->skb, 0, + nskb = skb_copy_expand(e->skb, 0, diff - skb_tailroom(e->skb), GFP_ATOMIC); - if (err) { + if (!nskb) { printk(KERN_WARNING "ip6_queue: OOM " "in mangle, dropping packet\n"); - return err; + return -ENOMEM; } + kfree_skb(e->skb); + e->skb = nskb; } skb_put(e->skb, diff); } diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c index 3ceeffc..561c974 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -616,8 +616,8 @@ err_out_put: static int nfqnl_mangle(void *data, int data_len, struct nfqnl_queue_entry *e) { + struct sk_buff *nskb; int diff; - int err; diff = data_len - e->skb->len; if (diff < 0) { @@ -627,14 +627,16 @@ nfqnl_mangle(void *data, int data_len, struct nfqnl_queue_entry *e) if (data_len > 0xFFFF) return -EINVAL; if (diff > skb_tailroom(e->skb)) { - err = pskb_expand_head(e->skb, 0, + nskb = skb_copy_expand(e->skb, 0, diff - skb_tailroom(e->skb), GFP_ATOMIC); - if (err) { + if (!nskb) { printk(KERN_WARNING "nf_queue: OOM " "in mangle, dropping packet\n"); - return err; + return -ENOMEM; } + kfree_skb(e->skb); + e->skb = nskb; } skb_put(e->skb, diff); }