[GIT PULL] Security subsystem update

From: James Morris
Date: Tue Jan 19 2016 - 18:32:38 EST


Please pull this update, which includes a CVE fix and a maintainers file
update.

The following changes since commit d05d82f7110b08fd36178a641b69a1f206e1142b:

Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile (2016-01-18 12:57:18 -0800)

are available in the git repository at:

git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security.git for-linus

David Howells (1):
Fix the MAINTAINERS record for the certs/ directory

Yevgeny Pats (1):
KEYS: Fix keyring ref leak in join_session_keyring()

MAINTAINERS | 3 ++-
security/keys/process_keys.c | 1 +
2 files changed, 3 insertions(+), 1 deletions(-)

---

commit 23567fd052a9abb6d67fe8e7a9ccdd9800a540f2
Author: Yevgeny Pats <yevgeny@xxxxxxxxxxxxxxxxxxx>
Date: Tue Jan 19 22:09:04 2016 +0000

KEYS: Fix keyring ref leak in join_session_keyring()

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@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Acked-by: Don Zickus <dzickus@xxxxxxxxxx>
Acked-by: Prarit Bhargava <prarit@xxxxxxxxxx>
Acked-by: Jarod Wilson <jarod@xxxxxxxxxx>
Signed-off-by: James Morris <james.l.morris@xxxxxxxxxx>

diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index a3f85d2..e6d5017 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;
}

commit d8d803867ac13117b8f6c6572474ab1c90e9036b
Author: David Howells <dhowells@xxxxxxxxxx>
Date: Thu Jan 14 15:50:20 2016 +0000

Fix the MAINTAINERS record for the certs/ directory

Fix the MAINTAINERS record for the certs/ directory to have the new
keyrings mailing list and also to be authoritative for the sign-file tool

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Acked-by: David Woodhouse <David.Woodhouse@xxxxxxxxx>
Signed-off-by: James Morris <james.l.morris@xxxxxxxxxx>

diff --git a/MAINTAINERS b/MAINTAINERS
index 95eafcc..3b45a1b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2706,10 +2706,11 @@ F: fs/ceph/
CERTIFICATE HANDLING:
M: David Howells <dhowells@xxxxxxxxxx>
M: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
-L: keyrings@xxxxxxxxxxxxx
+L: keyrings@xxxxxxxxxxxxxxx
S: Maintained
F: Documentation/module-signing.txt
F: certs/
+F: scripts/sign-file.c
F: scripts/extract-cert.c

CERTIFIED WIRELESS USB (WUSB) SUBSYSTEM: