From: Sasha Levin <sashal@kernel•org>
To: linux-kernel@vger•kernel.org, stable@vger•kernel.org
Cc: Sabrina Dubroca <sd@queasysnail•net>,
Steffen Klassert <steffen.klassert@secunet•com>,
Sasha Levin <sashal@kernel•org>,
netdev@vger•kernel.org
Subject: [PATCH AUTOSEL 5.0 06/34] esp4: add length check for UDP encapsulation
Date: Thu, 16 May 2019 07:39:03 -0400 [thread overview]
Message-ID: <20190516113932.8348-6-sashal@kernel.org> (raw)
In-Reply-To: <20190516113932.8348-1-sashal@kernel.org>
From: Sabrina Dubroca <sd@queasysnail•net>
[ Upstream commit 8dfb4eba4100e7cdd161a8baef2d8d61b7a7e62e ]
esp_output_udp_encap can produce a length that doesn't fit in the 16
bits of a UDP header's length field. In that case, we'll send a
fragmented packet whose length is larger than IP_MAX_MTU (resulting in
"Oversized IP packet" warnings on receive) and with a bogus UDP
length.
To prevent this, add a length check to esp_output_udp_encap and return
-EMSGSIZE on failure.
This seems to be older than git history.
Signed-off-by: Sabrina Dubroca <sd@queasysnail•net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet•com>
Signed-off-by: Sasha Levin <sashal@kernel•org>
---
net/ipv4/esp4.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 10e809b296ec8..fb065a8937ea2 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -226,7 +226,7 @@ static void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto)
tail[plen - 1] = proto;
}
-static void esp_output_udp_encap(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
+static int esp_output_udp_encap(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
{
int encap_type;
struct udphdr *uh;
@@ -234,6 +234,7 @@ static void esp_output_udp_encap(struct xfrm_state *x, struct sk_buff *skb, stru
__be16 sport, dport;
struct xfrm_encap_tmpl *encap = x->encap;
struct ip_esp_hdr *esph = esp->esph;
+ unsigned int len;
spin_lock_bh(&x->lock);
sport = encap->encap_sport;
@@ -241,11 +242,14 @@ static void esp_output_udp_encap(struct xfrm_state *x, struct sk_buff *skb, stru
encap_type = encap->encap_type;
spin_unlock_bh(&x->lock);
+ len = skb->len + esp->tailen - skb_transport_offset(skb);
+ if (len + sizeof(struct iphdr) >= IP_MAX_MTU)
+ return -EMSGSIZE;
+
uh = (struct udphdr *)esph;
uh->source = sport;
uh->dest = dport;
- uh->len = htons(skb->len + esp->tailen
- - skb_transport_offset(skb));
+ uh->len = htons(len);
uh->check = 0;
switch (encap_type) {
@@ -262,6 +266,8 @@ static void esp_output_udp_encap(struct xfrm_state *x, struct sk_buff *skb, stru
*skb_mac_header(skb) = IPPROTO_UDP;
esp->esph = esph;
+
+ return 0;
}
int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp)
@@ -275,8 +281,12 @@ int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *
int tailen = esp->tailen;
/* this is non-NULL only with UDP Encapsulation */
- if (x->encap)
- esp_output_udp_encap(x, skb, esp);
+ if (x->encap) {
+ int err = esp_output_udp_encap(x, skb, esp);
+
+ if (err < 0)
+ return err;
+ }
if (!skb_cloned(skb)) {
if (tailen <= skb_tailroom(skb)) {
--
2.20.1
next prev parent reply other threads:[~2019-05-16 11:39 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-16 11:38 [PATCH AUTOSEL 5.0 01/34] xfrm: policy: Fix out-of-bound array accesses in __xfrm_policy_unlink Sasha Levin
2019-05-16 11:38 ` [PATCH AUTOSEL 5.0 02/34] xfrm: Reset secpath in xfrm failure Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 03/34] xfrm6_tunnel: Fix potential panic when unloading xfrm6_tunnel module Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 04/34] vti4: ipip tunnel deregistration fixes Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 05/34] xfrm: clean up xfrm protocol checks Sasha Levin
2019-05-16 11:39 ` Sasha Levin [this message]
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 07/34] xfrm: Honor original L3 slave device in xfrmi policy lookup Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 08/34] xfrm4: Fix uninitialized memory read in _decode_session4 Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 18/34] mac80211: Fix kernel panic due to use of txq after free Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 19/34] net: ieee802154: fix missing checks for regmap_update_bits Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 22/34] tools: bpftool: fix infinite loop in map create Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 23/34] bpf: Fix preempt_enable_no_resched() abuse Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 24/34] qmi_wwan: new Wistron, ZTE and D-Link devices Sasha Levin
2019-05-16 11:39 ` [PATCH AUTOSEL 5.0 25/34] iwlwifi: mvm: check for length correctness in iwl_mvm_create_skb() Sasha Levin
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