From db86be3a12d0b6e5c5b51c2ab2a48f06329cb590 Mon Sep 17 00:00:00 2001
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Tue, 22 Aug 2017 23:41:28 +0300
Subject: [PATCH] eCryptfs: use after free in ecryptfs_release_messaging()
Git-commit: db86be3a12d0b6e5c5b51c2ab2a48f06329cb590
Patch-mainline: v4.15-rc1
References: bsc#1052766

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>
Cc: <stable@vger.kernel.org>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Jan Kara <jack@suse.cz>

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

diff --git a/fs/ecryptfs/messaging.c b/fs/ecryptfs/messaging.c
index 286f10b0363b..4f457d5c4933 100644
--- 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 "
-- 
2.12.3