From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:50878 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751892AbdJXIqH (ORCPT ); Tue, 24 Oct 2017 04:46:07 -0400 Subject: Patch "fscrypt: fix dereference of NULL user_key_payload" has been added to the 4.13-stable tree To: ebiggers@google.com, dhowells@redhat.com, gregkh@linuxfoundation.org, james.l.morris@oracle.com Cc: , From: Date: Tue, 24 Oct 2017 10:04:15 +0200 Message-ID: <150883225550168@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled fscrypt: fix dereference of NULL user_key_payload to the 4.13-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: fscrypt-fix-dereference-of-null-user_key_payload.patch and it can be found in the queue-4.13 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From d60b5b7854c3d135b869f74fb93eaf63cbb1991a Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Mon, 9 Oct 2017 12:46:18 -0700 Subject: fscrypt: fix dereference of NULL user_key_payload From: Eric Biggers commit d60b5b7854c3d135b869f74fb93eaf63cbb1991a upstream. When an fscrypt-encrypted file is opened, we request the file's master key from the keyrings service as a logon key, then access its payload. However, a revoked key has a NULL payload, and we failed to check for this. request_key() *does* skip revoked keys, but there is still a window where the key can be revoked before we acquire its semaphore. Fix it by checking for a NULL payload, treating it like a key which was already revoked at the time it was requested. Fixes: 88bd6ccdcdd6 ("ext4 crypto: add encryption key management facilities") Reviewed-by: James Morris Signed-off-by: Eric Biggers Signed-off-by: David Howells Signed-off-by: Greg Kroah-Hartman --- fs/crypto/keyinfo.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/fs/crypto/keyinfo.c +++ b/fs/crypto/keyinfo.c @@ -109,6 +109,11 @@ static int validate_user_key(struct fscr goto out; } ukp = user_key_payload_locked(keyring_key); + if (!ukp) { + /* key was revoked before we acquired its semaphore */ + res = -EKEYREVOKED; + goto out; + } if (ukp->datalen != sizeof(struct fscrypt_key)) { res = -EINVAL; goto out; Patches currently in stable-queue which might be from ebiggers@google.com are queue-4.13/keys-fix-race-between-updating-and-finding-a-negative-key.patch queue-4.13/fs-cache-fix-dereference-of-null-user_key_payload.patch queue-4.13/lib-digsig-fix-dereference-of-null-user_key_payload.patch queue-4.13/ecryptfs-fix-dereference-of-null-user_key_payload.patch queue-4.13/fscrypt-fix-dereference-of-null-user_key_payload.patch queue-4.13/keys-encrypted-fix-dereference-of-null-user_key_payload.patch queue-4.13/keys-don-t-let-add_key-update-an-uninstantiated-key.patch