From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:51208 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932402AbdJYJr7 (ORCPT ); Wed, 25 Oct 2017 05:47:59 -0400 Subject: Patch "fscrypt: fix dereference of NULL user_key_payload" has been added to the 4.4-stable tree To: ebiggers@google.com, dhowells@redhat.com, gregkh@linuxfoundation.org, james.l.morris@oracle.com, stable@vger.kernel.org Cc: , From: Date: Wed, 25 Oct 2017 11:47:56 +0200 Message-ID: <150892487614846@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 4.4-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-4.4 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 Cc: [v4.1+] Signed-off-by: Eric Biggers Signed-off-by: David Howells Signed-off-by: Greg Kroah-Hartman --- fs/ext4/crypto_key.c | 6 ++++++ fs/f2fs/crypto_key.c | 6 ++++++ 2 files changed, 12 insertions(+) --- a/fs/ext4/crypto_key.c +++ b/fs/ext4/crypto_key.c @@ -204,6 +204,12 @@ int ext4_get_encryption_info(struct inod } down_read(&keyring_key->sem); ukp = user_key_payload(keyring_key); + if (!ukp) { + /* key was revoked before we acquired its semaphore */ + res = -EKEYREVOKED; + up_read(&keyring_key->sem); + goto out; + } if (ukp->datalen != sizeof(struct ext4_encryption_key)) { res = -EINVAL; up_read(&keyring_key->sem); --- a/fs/f2fs/crypto_key.c +++ b/fs/f2fs/crypto_key.c @@ -195,6 +195,12 @@ int f2fs_get_encryption_info(struct inod } down_read(&keyring_key->sem); ukp = user_key_payload(keyring_key); + if (!ukp) { + /* key was revoked before we acquired its semaphore */ + res = -EKEYREVOKED; + up_read(&keyring_key->sem); + goto out; + } if (ukp->datalen != sizeof(struct f2fs_encryption_key)) { res = -EINVAL; up_read(&keyring_key->sem); Patches currently in stable-queue which might be from ebiggers@google.com are queue-4.4/keys-fix-race-between-updating-and-finding-a-negative-key.patch queue-4.4/fscrypto-require-write-access-to-mount-to-set-encryption-policy.patch queue-4.4/fs-cache-fix-dereference-of-null-user_key_payload.patch queue-4.4/lib-digsig-fix-dereference-of-null-user_key_payload.patch queue-4.4/fscrypt-fix-dereference-of-null-user_key_payload.patch queue-4.4/f2fs-crypto-add-missing-locking-for-keyring_key-access.patch queue-4.4/keys-encrypted-fix-dereference-of-null-user_key_payload.patch queue-4.4/f2fs-crypto-replace-some-bug_on-s-with-error-checks.patch queue-4.4/keys-don-t-let-add_key-update-an-uninstantiated-key.patch