Thread (1 message) 1 message, 1 author, 2011-05-05

[RFC v4 02/11] lsm: reintroduce security_socket_post_accept()

From: <hidden>
Date: 2011-05-05 13:59:12
Also in: netfilter-devel
Subsystem: networking [general], networking [sockets], security subsystem, the rest · Maintainers: "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds

Possibly related (same subject, not in this thread)

From: Samir Bellabes <redacted>

snet needs to reintroduce this hook, as it was designed to be: a hook for
updating security informations on objects.

Originally, This was a direct revert of commit
8651d5c0b1f874c5b8307ae2b858bc40f9f02482.

But from the comment of Tetsuo Handa [off-list ref] :
Please move security_socket_post_accept() to before fd_install().
Otherwise, other threads which share fd tables can use
security-informations-not-yet-updated accept()ed sockets.
Signed-off-by: Samir Bellabes <redacted>
Acked-by: Serge Hallyn <redacted>
---
 include/linux/security.h |   13 +++++++++++++
 net/socket.c             |    2 ++
 security/capability.c    |    5 +++++
 security/security.c      |    5 +++++
 4 files changed, 25 insertions(+), 0 deletions(-)
diff --git a/include/linux/security.h b/include/linux/security.h
index da0d59e..02effe5 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -875,6 +875,11 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
  *	@sock contains the listening socket structure.
  *	@newsock contains the newly created server socket for connection.
  *	Return 0 if permission is granted.
+ * @socket_post_accept:
+ *	This hook allows a security module to copy security
+ *	information into the newly created socket's inode.
+ *	@sock contains the listening socket structure.
+ *	@newsock contains the newly created server socket for connection.
  * @socket_sendmsg:
  *	Check permission before transmitting a message to another socket.
  *	@sock contains the socket structure.
@@ -1587,6 +1592,8 @@ struct security_operations {
 			       struct sockaddr *address, int addrlen);
 	int (*socket_listen) (struct socket *sock, int backlog);
 	int (*socket_accept) (struct socket *sock, struct socket *newsock);
+	void (*socket_post_accept) (struct socket *sock,
+				    struct socket *newsock);
 	int (*socket_sendmsg) (struct socket *sock,
 			       struct msghdr *msg, int size);
 	int (*socket_recvmsg) (struct socket *sock,
@@ -2555,6 +2562,7 @@ int security_socket_bind(struct socket *sock, struct sockaddr *address, int addr
 int security_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen);
 int security_socket_listen(struct socket *sock, int backlog);
 int security_socket_accept(struct socket *sock, struct socket *newsock);
+void security_socket_post_accept(struct socket *sock, struct socket *newsock);
 int security_socket_sendmsg(struct socket *sock, struct msghdr *msg, int size);
 int security_socket_recvmsg(struct socket *sock, struct msghdr *msg,
 			    int size, int flags);
@@ -2640,6 +2648,11 @@ static inline int security_socket_accept(struct socket *sock,
 	return 0;
 }
 
+static inline void security_socket_post_accept(struct socket *sock,
+					       struct socket *newsock)
+{
+}
+
 static inline int security_socket_sendmsg(struct socket *sock,
 					  struct msghdr *msg, int size)
 {
diff --git a/net/socket.c b/net/socket.c
index d588e9e..7807904 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1535,6 +1535,8 @@ SYSCALL_DEFINE4(accept4, int, fd, struct sockaddr __user *, upeer_sockaddr,
 			goto out_fd;
 	}
 
+	security_socket_post_accept(sock, newsock);
+
 	/* File flags are not inherited via accept() unlike another OSes. */
 
 	fd_install(newfd, newfile);
diff --git a/security/capability.c b/security/capability.c
index 1f8bbe2..da68c60 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -593,6 +593,10 @@ static int cap_socket_accept(struct socket *sock, struct socket *newsock)
 	return 0;
 }
 
+static void cap_socket_post_accept(struct socket *sock, struct socket *newsock)
+{
+}
+
 static int cap_socket_sendmsg(struct socket *sock, struct msghdr *msg, int size)
 {
 	return 0;
@@ -1022,6 +1026,7 @@ void __init security_fixup_ops(struct security_operations *ops)
 	set_to_cap_if_null(ops, socket_connect);
 	set_to_cap_if_null(ops, socket_listen);
 	set_to_cap_if_null(ops, socket_accept);
+	set_to_cap_if_null(ops, socket_post_accept);
 	set_to_cap_if_null(ops, socket_sendmsg);
 	set_to_cap_if_null(ops, socket_recvmsg);
 	set_to_cap_if_null(ops, socket_getsockname);
diff --git a/security/security.c b/security/security.c
index 84187d8..eda2b75 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1038,6 +1038,11 @@ int security_socket_accept(struct socket *sock, struct socket *newsock)
 	return security_ops->socket_accept(sock, newsock);
 }
 
+void security_socket_post_accept(struct socket *sock, struct socket *newsock)
+{
+	security_ops->socket_post_accept(sock, newsock);
+}
+
 int security_socket_sendmsg(struct socket *sock, struct msghdr *msg, int size)
 {
 	return security_ops->socket_sendmsg(sock, msg, size);
-- 
1.7.4.1
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