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authorEric Dumazet <edumazet@google.com>2016-10-20 09:39:40 -0700
committerDavid S. Miller <davem@davemloft.net>2016-10-20 14:45:52 -0400
commit286c72deabaa240b7eebbd99496ed3324d69f3c0 (patch)
tree00a0b07bfc20b08a025720c4c1b3c724ed4eaf67
parentnet: dsa: bcm_sf2: Prevent GPHY shutdown for kexec'd kernels (diff)
downloadlinux-dev-286c72deabaa240b7eebbd99496ed3324d69f3c0.tar.xz
linux-dev-286c72deabaa240b7eebbd99496ed3324d69f3c0.zip
udp: must lock the socket in udp_disconnect()
Baozeng Ding reported KASAN traces showing uses after free in udp_lib_get_port() and other related UDP functions. A CONFIG_DEBUG_PAGEALLOC=y kernel would eventually crash. I could write a reproducer with two threads doing : static int sock_fd; static void *thr1(void *arg) { for (;;) { connect(sock_fd, (const struct sockaddr *)arg, sizeof(struct sockaddr_in)); } } static void *thr2(void *arg) { struct sockaddr_in unspec; for (;;) { memset(&unspec, 0, sizeof(unspec)); connect(sock_fd, (const struct sockaddr *)&unspec, sizeof(unspec)); } } Problem is that udp_disconnect() could run without holding socket lock, and this was causing list corruptions. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Baozeng Ding <sploving1@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/udp.h1
-rw-r--r--net/ipv4/ping.c2
-rw-r--r--net/ipv4/raw.c2
-rw-r--r--net/ipv4/udp.c13
-rw-r--r--net/ipv6/ping.c2
-rw-r--r--net/ipv6/raw.c2
-rw-r--r--net/l2tp/l2tp_ip.c2
-rw-r--r--net/l2tp/l2tp_ip6.c2
8 files changed, 18 insertions, 8 deletions
diff --git a/include/net/udp.h b/include/net/udp.h
index ea53a87d880f..4948790d393d 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -258,6 +258,7 @@ void udp_flush_pending_frames(struct sock *sk);
void udp4_hwcsum(struct sk_buff *skb, __be32 src, __be32 dst);
int udp_rcv(struct sk_buff *skb);
int udp_ioctl(struct sock *sk, int cmd, unsigned long arg);
+int __udp_disconnect(struct sock *sk, int flags);
int udp_disconnect(struct sock *sk, int flags);
unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait);
struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 7cf7d6e380c2..205e2000d395 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -994,7 +994,7 @@ struct proto ping_prot = {
.init = ping_init_sock,
.close = ping_close,
.connect = ip4_datagram_connect,
- .disconnect = udp_disconnect,
+ .disconnect = __udp_disconnect,
.setsockopt = ip_setsockopt,
.getsockopt = ip_getsockopt,
.sendmsg = ping_v4_sendmsg,
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 90a85c955872..ecbe5a7c2d6d 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -918,7 +918,7 @@ struct proto raw_prot = {
.close = raw_close,
.destroy = raw_destroy,
.connect = ip4_datagram_connect,
- .disconnect = udp_disconnect,
+ .disconnect = __udp_disconnect,
.ioctl = raw_ioctl,
.init = raw_init,
.setsockopt = raw_setsockopt,
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 7d96dc2d3d08..311613e413cb 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1345,7 +1345,7 @@ csum_copy_err:
goto try_again;
}
-int udp_disconnect(struct sock *sk, int flags)
+int __udp_disconnect(struct sock *sk, int flags)
{
struct inet_sock *inet = inet_sk(sk);
/*
@@ -1367,6 +1367,15 @@ int udp_disconnect(struct sock *sk, int flags)
sk_dst_reset(sk);
return 0;
}
+EXPORT_SYMBOL(__udp_disconnect);
+
+int udp_disconnect(struct sock *sk, int flags)
+{
+ lock_sock(sk);
+ __udp_disconnect(sk, flags);
+ release_sock(sk);
+ return 0;
+}
EXPORT_SYMBOL(udp_disconnect);
void udp_lib_unhash(struct sock *sk)
@@ -2193,7 +2202,7 @@ int udp_abort(struct sock *sk, int err)
sk->sk_err = err;
sk->sk_error_report(sk);
- udp_disconnect(sk, 0);
+ __udp_disconnect(sk, 0);
release_sock(sk);
diff --git a/net/ipv6/ping.c b/net/ipv6/ping.c
index 0e983b694ee8..66e2d9dfc43a 100644
--- a/net/ipv6/ping.c
+++ b/net/ipv6/ping.c
@@ -180,7 +180,7 @@ struct proto pingv6_prot = {
.init = ping_init_sock,
.close = ping_close,
.connect = ip6_datagram_connect_v6_only,
- .disconnect = udp_disconnect,
+ .disconnect = __udp_disconnect,
.setsockopt = ipv6_setsockopt,
.getsockopt = ipv6_getsockopt,
.sendmsg = ping_v6_sendmsg,
diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c
index 54404f08efcc..054a1d84fc5e 100644
--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -1241,7 +1241,7 @@ struct proto rawv6_prot = {
.close = rawv6_close,
.destroy = raw6_destroy,
.connect = ip6_datagram_connect_v6_only,
- .disconnect = udp_disconnect,
+ .disconnect = __udp_disconnect,
.ioctl = rawv6_ioctl,
.init = rawv6_init_sk,
.setsockopt = rawv6_setsockopt,
diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c
index 42de4ccd159f..fce25afb652a 100644
--- a/net/l2tp/l2tp_ip.c
+++ b/net/l2tp/l2tp_ip.c
@@ -338,7 +338,7 @@ static int l2tp_ip_disconnect(struct sock *sk, int flags)
if (sock_flag(sk, SOCK_ZAPPED))
return 0;
- return udp_disconnect(sk, flags);
+ return __udp_disconnect(sk, flags);
}
static int l2tp_ip_getname(struct socket *sock, struct sockaddr *uaddr,
diff --git a/net/l2tp/l2tp_ip6.c b/net/l2tp/l2tp_ip6.c
index ea2ae6664cc8..ad3468c32b53 100644
--- a/net/l2tp/l2tp_ip6.c
+++ b/net/l2tp/l2tp_ip6.c
@@ -410,7 +410,7 @@ static int l2tp_ip6_disconnect(struct sock *sk, int flags)
if (sock_flag(sk, SOCK_ZAPPED))
return 0;
- return udp_disconnect(sk, flags);
+ return __udp_disconnect(sk, flags);
}
static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr,