[34-longterm 237/247] CAN: Use inode instead of kernel address for /proc file

Paul Gortmaker
2011-06-23T17:38:48Z

From: Dan Rosenberg <drosenberg@vsecurity.com>

-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.
-------------------

commit 9f260e0efa4766e56d0ac14f1aeea6ee5eb8fe83 upstream.

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>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
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 b8f7a2f..dd23fb1 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)
@@ -1523,7 +1523,7 @@ 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);
--
1.7.4.4