diff options
| author | Yevgeny Pats <yevgeny@perception-point.io> | 2016-01-19 22:09:04 +0000 |
|---|---|---|
| committer | Kees Cook <keescook@google.com> | 2016-01-21 22:34:57 +0000 |
| commit | 2a6d784299cb4183af5f735185bd286050e4af17 (patch) | |
| tree | f0072d7f58d6fa8a3a8402258aa0b2aae1c1d884 | |
| parent | 4a776375a52a1b187416dc332c4fa628fc628ee9 (diff) | |
| download | v4.1-brillo-m8-dev.tar.gz | |
UPSTREAM: KEYS: Fix keyring ref leak in join_session_keyring()brillo-m8-dev
This fixes CVE-2016-0728.
If a thread is asked to join as a session keyring the keyring that's already
set as its session, we leak a keyring reference.
This can be tested with the following program:
#include <stddef.h>
#include <stdio.h>
#include <sys/types.h>
#include <keyutils.h>
int main(int argc, const char *argv[])
{
int i = 0;
key_serial_t serial;
serial = keyctl(KEYCTL_JOIN_SESSION_KEYRING,
"leaked-keyring");
if (serial < 0) {
perror("keyctl");
return -1;
}
if (keyctl(KEYCTL_SETPERM, serial,
KEY_POS_ALL | KEY_USR_ALL) < 0) {
perror("keyctl");
return -1;
}
for (i = 0; i < 100; i++) {
serial = keyctl(KEYCTL_JOIN_SESSION_KEYRING,
"leaked-keyring");
if (serial < 0) {
perror("keyctl");
return -1;
}
}
return 0;
}
If, after the program has run, there something like the following line in
/proc/keys:
3f3d898f I--Q--- 100 perm 3f3f0000 0 0 keyring leaked-keyring: empty
with a usage count of 100 * the number of times the program has been run,
then the kernel is malfunctioning. If leaked-keyring has zero usages or
has been garbage collected, then the problem is fixed.
Reported-by: Yevgeny Pats <yevgeny@perception-point.io>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Acked-by: Prarit Bhargava <prarit@redhat.com>
Acked-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Bug: 26692844
(cherry picked from commit 23567fd052a9abb6d67fe8e7a9ccdd9800a540f2)
Signed-off-by: Kees Cook <keescook@chromium.org>
Change-Id: I4043bffac931fda6f238ab0a678fa9182f9f9e7f
(cherry picked from commit 8a897d8a6a3c6bb96c89e593bc1df85e8784f124)
| -rw-r--r-- | security/keys/process_keys.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index bd536cb221e..db91639c81e 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -794,6 +794,7 @@ long join_session_keyring(const char *name) ret = PTR_ERR(keyring); goto error2; } else if (keyring == new->session_keyring) { + key_put(keyring); ret = 0; goto error2; } |