[PATCH v2] CAN: Use inode instead of kernel address for /proc file

[Dan Rosenberg <drosenberg@vsecurity.com>]

Since the socket address is just being used as a unique identifier, its
inode number is an alternative that does not leak potentially sensitive
information.

CC-ing stable because MITRE has assigned CVE-2010-4565 to the issue.

Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: stable <stable@kernel.org>
---
 net/can/bcm.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/can/bcm.c b/net/can/bcm.c
index 6faa825..bc51b56 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -125,7 +125,7 @@ struct bcm_sock {
 	struct list_head tx_ops;
 	unsigned long dropped_usr_msgs;
 	struct proc_dir_entry *bcm_proc_read;
-	char procname [20]; /* pointer printed in ASCII with \0 */
+	char procname [32]; /* inode number in decimal with \0 */
 };
 
 static inline struct bcm_sock *bcm_sk(const struct sock *sk)
@@ -1521,7 +1521,7 @@ static int bcm_connect(struct socket *sock, struct sockaddr *uaddr, int len,
 
 	if (proc_dir) {
 		/* unique socket address as filename */
-		sprintf(bo->procname, "%p", sock);
+		sprintf(bo->procname, "%lu", sock_i_ino(sk));
 		bo->bcm_proc_read = proc_create_data(bo->procname, 0644,
 						     proc_dir,
 						     &bcm_proc_fops, sk);