[PATCH 4.8 12/45] udplite: call proper backlog handlers

From: Greg Kroah-Hartman
Date: Fri Dec 09 2016 - 11:31:04 EST


4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Eric Dumazet <edumazet@xxxxxxxxxx>


[ Upstream commit 30c7be26fd3587abcb69587f781098e3ca2d565b ]

In commits 93821778def10 ("udp: Fix rcv socket locking") and
f7ad74fef3af ("net/ipv6/udp: UDP encapsulation: break backlog_rcv into
__udpv6_queue_rcv_skb") UDP backlog handlers were renamed, but UDPlite
was forgotten.

This leads to crashes if UDPlite header is pulled twice, which happens
starting from commit e6afc8ace6dd ("udp: remove headers from UDP packets
before queueing")

Bug found by syzkaller team, thanks a lot guys !

Note that backlog use in UDP/UDPlite is scheduled to be removed starting
from linux-4.10, so this patch is only needed up to linux-4.9

Fixes: 93821778def1 ("udp: Fix rcv socket locking")
Fixes: f7ad74fef3af ("net/ipv6/udp: UDP encapsulation: break backlog_rcv into __udpv6_queue_rcv_skb")
Fixes: e6afc8ace6dd ("udp: remove headers from UDP packets before queueing")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reported-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Cc: Benjamin LaHaise <bcrl@xxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv4/udp.c | 2 +-
net/ipv4/udp_impl.h | 2 +-
net/ipv4/udplite.c | 2 +-
net/ipv6/udp.c | 2 +-
net/ipv6/udp_impl.h | 2 +-
net/ipv6/udplite.c | 2 +-
6 files changed, 6 insertions(+), 6 deletions(-)

--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1451,7 +1451,7 @@ static void udp_v4_rehash(struct sock *s
udp_lib_rehash(sk, new_hash);
}

-static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
int rc;

--- a/net/ipv4/udp_impl.h
+++ b/net/ipv4/udp_impl.h
@@ -25,7 +25,7 @@ int udp_recvmsg(struct sock *sk, struct
int flags, int *addr_len);
int udp_sendpage(struct sock *sk, struct page *page, int offset, size_t size,
int flags);
-int udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
+int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
void udp_destroy_sock(struct sock *sk);

#ifdef CONFIG_PROC_FS
--- a/net/ipv4/udplite.c
+++ b/net/ipv4/udplite.c
@@ -50,7 +50,7 @@ struct proto udplite_prot = {
.sendmsg = udp_sendmsg,
.recvmsg = udp_recvmsg,
.sendpage = udp_sendpage,
- .backlog_rcv = udp_queue_rcv_skb,
+ .backlog_rcv = __udp_queue_rcv_skb,
.hash = udp_lib_hash,
.unhash = udp_lib_unhash,
.get_port = udp_v4_get_port,
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -514,7 +514,7 @@ out:
return;
}

-static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
int rc;

--- a/net/ipv6/udp_impl.h
+++ b/net/ipv6/udp_impl.h
@@ -26,7 +26,7 @@ int compat_udpv6_getsockopt(struct sock
int udpv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len);
int udpv6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
int flags, int *addr_len);
-int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
+int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
void udpv6_destroy_sock(struct sock *sk);

void udp_v6_clear_sk(struct sock *sk, int size);
--- a/net/ipv6/udplite.c
+++ b/net/ipv6/udplite.c
@@ -45,7 +45,7 @@ struct proto udplitev6_prot = {
.getsockopt = udpv6_getsockopt,
.sendmsg = udpv6_sendmsg,
.recvmsg = udpv6_recvmsg,
- .backlog_rcv = udpv6_queue_rcv_skb,
+ .backlog_rcv = __udpv6_queue_rcv_skb,
.hash = udp_lib_hash,
.unhash = udp_lib_unhash,
.get_port = udp_v6_get_port,