net,socket: introduce DECLARE_SOCKADDR helper to catch overflow at build time (38bfd8f5) · Commits · 戴 / test

proto_ops->getname implies copying protocol specific data into storage unit (particulary to __kernel_sockaddr_storage). So when we implement new protocol support we should keep such a detail in mind (which is easy to forget about). Lets introduce DECLARE_SOCKADDR helper which check if storage unit is not overfowed at build time. Eventually inet_getname is switched to use DECLARE_SOCKADDR (to show example of usage). Signed-off-by:

Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by:

David S. Miller <davem@davemloft.net>

include/linux/net.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -199,6 +199,9 @@ struct proto_ops {
		struct pipe_inode_info *pipe, size_t len, unsigned int flags);
		};

		#define DECLARE_SOCKADDR(type, dst, src) \
		type dst = ({ __sockaddr_check_size(sizeof(*dst)); (type) src; })

		struct net_proto_family {
		int family;
		int (create)(struct net net, struct socket *sock, int protocol);

include/linux/socket.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -24,6 +24,9 @@ struct __kernel_sockaddr_storage {
		#include <linux/types.h> /* pid_t */
		#include <linux/compiler.h> /* __user */

		#define __sockaddr_check_size(size) \
		BUILD_BUG_ON(((size) > sizeof(struct __kernel_sockaddr_storage)))

		#ifdef __KERNEL__
		# ifdef CONFIG_PROC_FS
		struct seq_file;

net/ipv4/af_inet.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -685,7 +685,7 @@ int inet_getname(struct socket sock, struct sockaddr uaddr,
		{
		struct sock *sk = sock->sk;
		struct inet_sock *inet = inet_sk(sk);
		struct sockaddr_in sin = (struct sockaddr_in )uaddr;
		DECLARE_SOCKADDR(struct sockaddr_in *, sin, uaddr);

		sin->sin_family = AF_INET;
		if (peer) {

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