[PATCH 6.1 013/131] net: prevent address rewrite in kernel_bind()

Greg Kroah-Hartman
2023-10-16T08:54:55Z

From: Jordan Rife <jrife@google.com>

commit c889a99a21bf124c3db08d09df919f0eccc5ea4c upstream.

Similar to the change in commit 0bdf399342c5("net: Avoid address
overwrite in kernel_connect"), BPF hooks run on bind may rewrite the
address passed to kernel_bind(). This change

1) Makes a copy of the bind address in kernel_bind() to insulate
callers.
2) Replaces direct calls to sock->ops->bind() in net with kernel_bind()

Link: https://lore.kernel.org/netdev/20230912013332.2048422-1-jrife@google.com/
Fixes: 4fbac77d2d09 ("bpf: Hooks for sys_bind")
Cc: stable@vger.kernel.org
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jordan Rife <jrife@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/netfilter/ipvs/ip_vs_sync.c | 4 ++--
net/rds/tcp_connect.c | 2 +-
net/rds/tcp_listen.c | 2 +-
net/socket.c | 6 +++++-
4 files changed, 9 insertions(+), 5 deletions(-)

--- a/net/netfilter/ipvs/ip_vs_sync.c
+++ b/net/netfilter/ipvs/ip_vs_sync.c
@@ -1441,7 +1441,7 @@ static int bind_mcastif_addr(struct sock
sin.sin_addr.s_addr = addr;
sin.sin_port = 0;

- return sock->ops->bind(sock, (struct sockaddr*)&sin, sizeof(sin));
+ return kernel_bind(sock, (struct sockaddr *)&sin, sizeof(sin));
}

static void get_mcast_sockaddr(union ipvs_sockaddr *sa, int *salen,
@@ -1548,7 +1548,7 @@ static int make_receive_sock(struct netn

get_mcast_sockaddr(&mcast_addr, &salen, &ipvs->bcfg, id);
sock->sk->sk_bound_dev_if = dev->ifindex;
- result = sock->ops->bind(sock, (struct sockaddr *)&mcast_addr, salen);
+ result = kernel_bind(sock, (struct sockaddr *)&mcast_addr, salen);
if (result < 0) {
pr_err("Error binding to the multicast addr\n");
goto error;
--- a/net/rds/tcp_connect.c
+++ b/net/rds/tcp_connect.c
@@ -145,7 +145,7 @@ int rds_tcp_conn_path_connect(struct rds
addrlen = sizeof(sin);
}

- ret = sock->ops->bind(sock, addr, addrlen);
+ ret = kernel_bind(sock, addr, addrlen);
if (ret) {
rdsdebug("bind failed with %d at address %pI6c\n",
ret, &conn->c_laddr);
--- a/net/rds/tcp_listen.c
+++ b/net/rds/tcp_listen.c
@@ -304,7 +304,7 @@ struct socket *rds_tcp_listen_init(struc
addr_len = sizeof(*sin);
}

- ret = sock->ops->bind(sock, (struct sockaddr *)&ss, addr_len);
+ ret = kernel_bind(sock, (struct sockaddr *)&ss, addr_len);
if (ret < 0) {
rdsdebug("could not bind %s listener socket: %d\n",
isv6 ? "IPv6" : "IPv4", ret);
--- a/net/socket.c
+++ b/net/socket.c
@@ -3454,7 +3454,11 @@ static long compat_sock_ioctl(struct fil

int kernel_bind(struct socket *sock, struct sockaddr *addr, int addrlen)
{
- return sock->ops->bind(sock, addr, addrlen);
+ struct sockaddr_storage address;
+
+ memcpy(&address, addr, addrlen);
+
+ return sock->ops->bind(sock, (struct sockaddr *)&address, addrlen);
}
EXPORT_SYMBOL(kernel_bind);