From: Eric Dumazet <eduma...@google.com>
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 <eduma...@google.com>
Reported-by: Baozeng Ding <splovi...@gmail.com>
---
include/net/udp.h | 1 +
net/ipv4/ping.c | 2 +-
net/ipv4/raw.c | 2 +-
net/ipv4/udp.c | 13 +++++++++++--
net/ipv6/ping.c | 2 +-
net/ipv6/raw.c | 2 +-
net/l2tp/l2tp_ip.c | 2 +-
net/l2tp/l2tp_ip6.c | 2 +-
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 @@ int udp_recvmsg(struct sock *sk, struct msghdr *msg,
size_t len, int noblock,
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,
