[PATCH AUTOSEL 4.14 12/59] netfilter: seqadj: re-load tcp header pointer after possible head reallocation

[PATCH AUTOSEL 4.14 12/59] netfilter: seqadj: re-load tcp header pointer after possible head reallocation

[Sasha Levin]

From: Florian Westphal <fw@strlen.de>

[ Upstream commit 530aad77010b81526586dfc09130ec875cd084e4 ]

When adjusting sack block sequence numbers, skb_make_writable() gets
called to make sure tcp options are all in the linear area, and buffer
is not shared.

This can cause tcp header pointer to get reallocated, so we must
reaload it to avoid memory corruption.

This bug pre-dates git history.

Reported-by: Neel Mehta <nmehta@google.com>
Reported-by: Shane Huntley <shuntley@google.com>
Reported-by: Heather Adkins <argv@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/netfilter/nf_conntrack_seqadj.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/net/netfilter/nf_conntrack_seqadj.c b/net/netfilter/nf_conntrack_seqadj.c
index a975efd6b8c3..9da303461069 100644
--- a/net/netfilter/nf_conntrack_seqadj.c
+++ b/net/netfilter/nf_conntrack_seqadj.c
@@ -115,12 +115,12 @@ static void nf_ct_sack_block_adjust(struct sk_buff *skb,
 /* TCP SACK sequence number adjustment */
 static unsigned int nf_ct_sack_adjust(struct sk_buff *skb,
 				      unsigned int protoff,
-				      struct tcphdr *tcph,
 				      struct nf_conn *ct,
 				      enum ip_conntrack_info ctinfo)
 {
-	unsigned int dir, optoff, optend;
+	struct tcphdr *tcph = (void *)skb->data + protoff;
 	struct nf_conn_seqadj *seqadj = nfct_seqadj(ct);
+	unsigned int dir, optoff, optend;
 
 	optoff = protoff + sizeof(struct tcphdr);
 	optend = protoff + tcph->doff * 4;
@@ -128,6 +128,7 @@ static unsigned int nf_ct_sack_adjust(struct sk_buff *skb,
 	if (!skb_make_writable(skb, optend))
 		return 0;
 
+	tcph = (void *)skb->data + protoff;
 	dir = CTINFO2DIR(ctinfo);
 
 	while (optoff < optend) {
@@ -207,7 +208,7 @@ int nf_ct_seq_adjust(struct sk_buff *skb,
 		 ntohl(newack));
 	tcph->ack_seq = newack;
 
-	res = nf_ct_sack_adjust(skb, protoff, tcph, ct, ctinfo);
+	res = nf_ct_sack_adjust(skb, protoff, ct, ctinfo);
 out:
 	spin_unlock_bh(&ct->lock);
 
-- 
2.19.1

[PATCH AUTOSEL 4.14 22/59] netfilter: ipset: do not call ipset_nest_end after nla_nest_cancel

[Sasha Levin]

From: Pan Bian <bianpan2016@163.com>

[ Upstream commit 708abf74dd87f8640871b814faa195fb5970b0e3 ]

In the error handling block, nla_nest_cancel(skb, atd) is called to
cancel the nest operation. But then, ipset_nest_end(skb, atd) is
unexpected called to end the nest operation. This patch calls the
ipset_nest_end only on the branch that nla_nest_cancel is not called.

Fixes: 45040978c899 ("netfilter: ipset: Fix set:list type crash when flush/dump set in parallel")
Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/netfilter/ipset/ip_set_list_set.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/ipset/ip_set_list_set.c b/net/netfilter/ipset/ip_set_list_set.c
index 75d52aed6fdb..e563921e6af5 100644
--- a/net/netfilter/ipset/ip_set_list_set.c
+++ b/net/netfilter/ipset/ip_set_list_set.c
@@ -542,8 +542,8 @@ list_set_list(const struct ip_set *set,
 		ret = -EMSGSIZE;
 	} else {
 		cb->args[IPSET_CB_ARG0] = i;
+		ipset_nest_end(skb, atd);
 	}
-	ipset_nest_end(skb, atd);
 out:
 	rcu_read_unlock();
 	return ret;
-- 
2.19.1

[PATCH AUTOSEL 4.14 23/59] netfilter: nat: can't use dst_hold on noref dst

[Sasha Levin]

From: Florian Westphal <fw@strlen.de>

[ Upstream commit 542fbda0f08f1cbbc250f9e59f7537649651d0c8 ]

The dst entry might already have a zero refcount, waiting on rcu list
to be free'd.  Using dst_hold() transitions its reference count to 1, and
next dst release will try to free it again -- resulting in a double free:

  WARNING: CPU: 1 PID: 0 at include/net/dst.h:239 nf_xfrm_me_harder+0xe7/0x130 [nf_nat]
  RIP: 0010:nf_xfrm_me_harder+0xe7/0x130 [nf_nat]
  Code: 48 8b 5c 24 60 65 48 33 1c 25 28 00 00 00 75 53 48 83 c4 68 5b 5d 41 5c c3 85 c0 74 0d 8d 48 01 f0 0f b1 0a 74 86 85 c0 75 f3 <0f> 0b e9 7b ff ff ff 29 c6 31 d2 b9 20 00 48 00 4c 89 e7 e8 31 27
  Call Trace:
  nf_nat_ipv4_out+0x78/0x90 [nf_nat_ipv4]
  nf_hook_slow+0x36/0xd0
  ip_output+0x9f/0xd0
  ip_forward+0x328/0x440
  ip_rcv+0x8a/0xb0

Use dst_hold_safe instead and bail out if we cannot take a reference.

Fixes: a4c2fd7f7891 ("net: remove DST_NOCACHE flag")
Reported-by: Martin Zaharinov <micron10@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/netfilter/nf_nat_core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
index af8345fc4fbd..ed0ea64b8d04 100644
--- a/net/netfilter/nf_nat_core.c
+++ b/net/netfilter/nf_nat_core.c
@@ -97,7 +97,8 @@ int nf_xfrm_me_harder(struct net *net, struct sk_buff *skb, unsigned int family)
 	dst = skb_dst(skb);
 	if (dst->xfrm)
 		dst = ((struct xfrm_dst *)dst)->route;
-	dst_hold(dst);
+	if (!dst_hold_safe(dst))
+		return -EHOSTUNREACH;
 
 	dst = xfrm_lookup(net, dst, &fl, skb->sk, 0);
 	if (IS_ERR(dst))
-- 
2.19.1