From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:50276 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030529AbeBNO1E (ORCPT ); Wed, 14 Feb 2018 09:27:04 -0500 Subject: Patch "NFS: reject request for id_legacy key without auxdata" has been added to the 4.15-stable tree To: ebiggers@google.com, gregkh@linuxfoundation.org, trondmy@gmail.com Cc: , From: Date: Wed, 14 Feb 2018 15:26:32 +0100 Message-ID: <15186183921365@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 NFS: reject request for id_legacy key without auxdata to the 4.15-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: nfs-reject-request-for-id_legacy-key-without-auxdata.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 49686cbbb3ebafe42e63868222f269d8053ead00 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Fri, 19 Jan 2018 15:15:34 -0800 Subject: NFS: reject request for id_legacy key without auxdata From: Eric Biggers commit 49686cbbb3ebafe42e63868222f269d8053ead00 upstream. nfs_idmap_legacy_upcall() is supposed to be called with 'aux' pointing to a 'struct idmap', via the call to request_key_with_auxdata() in nfs_idmap_request_key(). However it can also be reached via the request_key() system call in which case 'aux' will be NULL, causing a NULL pointer dereference in nfs_idmap_prepare_pipe_upcall(), assuming that the key description is valid enough to get that far. Fix this by making nfs_idmap_legacy_upcall() negate the key if no auxdata is provided. As usual, this bug was found by syzkaller. A simple reproducer using the command-line keyctl program is: keyctl request2 id_legacy uid:0 '' @s Fixes: 57e62324e469 ("NFS: Store the legacy idmapper result in the keyring") Reported-by: syzbot+5dfdbcf7b3eb5912abbb@syzkaller.appspotmail.com Signed-off-by: Eric Biggers Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman --- fs/nfs/nfs4idmap.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/fs/nfs/nfs4idmap.c +++ b/fs/nfs/nfs4idmap.c @@ -568,9 +568,13 @@ static int nfs_idmap_legacy_upcall(struc struct idmap_msg *im; struct idmap *idmap = (struct idmap *)aux; struct key *key = cons->key; - int ret = -ENOMEM; + int ret = -ENOKEY; + + if (!aux) + goto out1; /* msg and im are freed in idmap_pipe_destroy_msg */ + ret = -ENOMEM; data = kzalloc(sizeof(*data), GFP_KERNEL); if (!data) goto out1; Patches currently in stable-queue which might be from ebiggers@google.com are queue-4.15/ubifs-free-the-encrypted-symlink-target.patch queue-4.15/nfs-reject-request-for-id_legacy-key-without-auxdata.patch