| Message ID | 1453672718-2301-1-git-send-email-luis.henriques@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index 0cf8a130a267..4e56371f239f 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -793,6 +793,7 @@ 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; }
This is a note to let you know that I have just added a patch titled KEYS: Fix keyring ref leak in join_session_keyring() to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt23. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ---8<------------------------------------------------------------ From f3e9ef6b8ef8849f32fb7929c0f1582f1c8354b1 Mon Sep 17 00:00:00 2001 From: Yevgeny Pats <yevgeny@perception-point.io> Date: Tue, 19 Jan 2016 22:09:04 +0000 Subject: KEYS: Fix keyring ref leak in join_session_keyring() commit 23567fd052a9abb6d67fe8e7a9ccdd9800a540f2 upstream. 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> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- security/keys/process_keys.c | 1 + 1 file changed, 1 insertion(+)