[PATCH 4.4 22/96] eCryptfs: use after free in ecryptfs_release_messaging()

Greg Kroah-Hartman
2017-11-28T10:28:59Z

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/ecryptfs/messaging.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

--- a/fs/ecryptfs/messaging.c
+++ b/fs/ecryptfs/messaging.c
@@ -442,15 +442,16 @@ void ecryptfs_release_messaging(void)
}
if (ecryptfs_daemon_hash) {
struct ecryptfs_daemon *daemon;
+ struct hlist_node *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,
- &ecryptfs_daemon_hash[i],
- euid_chain) {
+ hlist_for_each_entry_safe(daemon, n,
+ &ecryptfs_daemon_hash[i],
+ euid_chain) {
rc = ecryptfs_exorcise_daemon(daemon);
if (rc)
printk(KERN_ERR "%s: Error whilst "