ubus: update to the latest version, fixes a memory leak on client disconnect
[openwrt.git] / target / linux / generic / patches-4.4 / 010-KEYS-Fix-keyring-ref-leak-in-join_session_keyring.patch
1 From 7ca88764d45c209791e8813131c1457c2e9e51e7 Mon Sep 17 00:00:00 2001
2 From: Yevgeny Pats <yevgeny@perception-point.io>
3 Date: Mon, 11 Jan 2016 12:05:28 +0000
4 Subject: KEYS: Fix keyring ref leak in join_session_keyring()
5
6 If a thread is asked to join as a session keyring the keyring that's already
7 set as its session, we leak a keyring reference.
8
9 This can be tested with the following program:
10
11         #include <stddef.h>
12         #include <stdio.h>
13         #include <sys/types.h>
14         #include <keyutils.h>
15
16         int main(int argc, const char *argv[])
17         {
18                 int i = 0;
19                 key_serial_t serial;
20
21                 serial = keyctl(KEYCTL_JOIN_SESSION_KEYRING,
22                                 "leaked-keyring");
23                 if (serial < 0) {
24                         perror("keyctl");
25                         return -1;
26                 }
27
28                 if (keyctl(KEYCTL_SETPERM, serial,
29                            KEY_POS_ALL | KEY_USR_ALL) < 0) {
30                         perror("keyctl");
31                         return -1;
32                 }
33
34                 for (i = 0; i < 100; i++) {
35                         serial = keyctl(KEYCTL_JOIN_SESSION_KEYRING,
36                                         "leaked-keyring");
37                         if (serial < 0) {
38                                 perror("keyctl");
39                                 return -1;
40                         }
41                 }
42
43                 return 0;
44         }
45
46 If, after the program has run, there something like the following line in
47 /proc/keys:
48
49 3f3d898f I--Q---   100 perm 3f3f0000     0     0 keyring   leaked-keyring: empty
50
51 with a usage count of 100 * the number of times the program has been run,
52 then the kernel is malfunctioning.  If leaked-keyring has zero usages or
53 has been garbage collected, then the problem is fixed.
54
55 Reported-by: Yevgeny Pats <yevgeny@perception-point.io>
56 Signed-off-by: David Howells <dhowells@redhat.com>
57 ---
58  security/keys/process_keys.c | 1 +
59  1 file changed, 1 insertion(+)
60
61 diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
62 index a3f85d2..e6d50172 100644
63 --- a/security/keys/process_keys.c
64 +++ b/security/keys/process_keys.c
65 @@ -794,6 +794,7 @@ long join_session_keyring(const char *name)
66                 ret = PTR_ERR(keyring);
67                 goto error2;
68         } else if (keyring == new->session_keyring) {
69 +               key_put(keyring);
70                 ret = 0;
71                 goto error2;
72         }
73 -- 
74 2.7.0.rc3
75