[PATCH 3.2 27/79] eCryptfs: use after free in ecryptfs_release_messaging()

Ben Hutchings
2018-02-11T04:20:06Z

From: Dan Carpenter <dan.carpenter@oracle.com>

commit db86be3a12d0b6e5c5b51c2ab2a48f06329cb590 upstream.

We're freeing the list iterator so we should be using the _safe()
version of hlist_for_each_entry().

Fixes: 88b4a07e6610 ("[PATCH] eCryptfs: Public key transport mechanism")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
--- a/fs/ecryptfs/messaging.c
+++ b/fs/ecryptfs/messaging.c
@@ -550,17 +550,17 @@ void ecryptfs_release_messaging(void)
mutex_unlock(&ecryptfs_msg_ctx_lists_mux);
}
if (ecryptfs_daemon_hash) {
- struct hlist_node *elem;
struct ecryptfs_daemon *daemon;
+ struct hlist_node *elem, *n;
int i;

mutex_lock(&ecryptfs_daemon_hash_mux);
for (i = 0; i < (1 << ecryptfs_hash_bits); i++) {
int rc;

- hlist_for_each_entry(daemon, elem,
- &ecryptfs_daemon_hash[i],
- euid_chain) {
+ hlist_for_each_entry_safe(daemon, elem, n,
+ &ecryptfs_daemon_hash[i],
+ euid_chain) {
rc = ecryptfs_exorcise_daemon(daemon);
if (rc)
printk(KERN_ERR "%s: Error whilst "