[Devel] [PATCH RHEL7 COMMIT] ms/KEYS: fix key refcount leak in keyctl_read_key()

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-693.1.1.vz7.37.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-693.1.1.vz7.37.19
------>
commit 5950e057c5666628aa8d2e672e5104bc2d521823
Author: Eric Biggers <ebiggers at google.com>
Date:   Mon Sep 18 11:36:31 2017 -0700

    ms/KEYS: fix key refcount leak in keyctl_read_key()
    
    In keyctl_read_key(), if key_permission() were to return an error code
    other than EACCES, we would leak a the reference to the key.  This can't
    actually happen currently because key_permission() can only return an
    error code other than EACCES if security_key_permission() does, only
    SELinux and Smack implement that hook, and neither can return an error
    code other than EACCES.  But it should still be fixed, as it is a bug
    waiting to happen.
    
    Fixes: 29db91906340 ("[PATCH] Keys: Add LSM hooks for key management [try #3]")
    Signed-off-by: Eric Biggers <ebiggers at google.com>
    Signed-off-by: David Howells <dhowells at redhat.com>
    
    https://jira.sw.ru/browse/PSBM-72405
    
    (cherry picked from commit 7fc0786d956d9e59b68d282be9b156179846ea3d)
    Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>
---
 security/keys/keyctl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 1f02193..fec97ae 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -758,7 +758,7 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
 	if (ret == 0)
 		goto can_read_key;
 	if (ret != -EACCES)
-		goto error;
+		goto error2;
 
 	/* we can't; see if it's searchable from this process's keyrings
 	 * - we automatically take account of the fact that it may be