CAN: Use inode instead of kernel address for /proc file

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>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/can/bcm.c b/net/can/bcm.c
index 6faa8256e10ca22d6fb0b2005d74c5c5580a404d..9d5e8accfab1d73f25e8a00ae45523a400b820ce 100644 (file)
--- 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);