From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:51220 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932402AbdJYJsB (ORCPT ); Wed, 25 Oct 2017 05:48:01 -0400 Subject: Patch "FS-Cache: 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 Cc: , From: Date: Wed, 25 Oct 2017 11:47:56 +0200 Message-ID: <150892487615432@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 FS-Cache: 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: fs-cache-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 d124b2c53c7bee6569d2a2d0b18b4a1afde00134 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Mon, 9 Oct 2017 12:40:00 -0700 Subject: FS-Cache: fix dereference of NULL user_key_payload From: Eric Biggers commit d124b2c53c7bee6569d2a2d0b18b4a1afde00134 upstream. When the file /proc/fs/fscache/objects (available with CONFIG_FSCACHE_OBJECT_LIST=y) is opened, we request a user key with description "fscache:objlist", 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 access its payload. Fix it by checking for a NULL payload, treating it like a key which was already revoked at the time it was requested. Fixes: 4fbf4291aa15 ("FS-Cache: Allow the current state of all objects to be dumped") Reviewed-by: James Morris Signed-off-by: Eric Biggers Signed-off-by: David Howells Signed-off-by: Greg Kroah-Hartman --- fs/fscache/object-list.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/fs/fscache/object-list.c +++ b/fs/fscache/object-list.c @@ -330,6 +330,13 @@ static void fscache_objlist_config(struc rcu_read_lock(); confkey = user_key_payload(key); + if (!confkey) { + /* key was revoked */ + rcu_read_unlock(); + key_put(key); + goto no_config; + } + buf = confkey->data; for (len = confkey->datalen - 1; len >= 0; len--) { 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