From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-600449-1516403843-2-15627417037171980223 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, FREEMAIL_FORGED_FROMDOMAIN 0.25, FREEMAIL_FROM 0.001, HEADER_FROM_DIFFERENT_DOMAINS 0.25, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='com', MailFrom='org' X-Spam-charsets: X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1516403843; b=Kdge5fO8/1hLeydjxtVCKqKHwZyQTtc/27doFlkC98miAQo qeI1hVxzlb+JTxr+m2J3W0aMkH+YNTlBam/NwSnZ0fR4q7igmkgo9g3YbvzlVydm 1rVoIymtxNWzetlEUbHm52sklmu2ffmSc1Po8GZA/K1ltvuzACKHY9OUDrsYnESs o4Bj4Zizyzg8BoIEfxDrRuMPRBqqC0zoUTfFHqgRBJsYVPzVghU3kbarDXWQK/ep v1auiRdjAexQXNwYgGES192UBDXafaFDvtH4ED0+hXNiURgKwOY1rOOB00ZNcA0/ Kzr3Aft4YJ56fu8hDWHn2blBfaG6aeu9MCrk7+A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:sender:list-id; s=arctest; t=1516403843; bh=aDJvdHJsBVlKKFCufJZM9km6KpXXQOYwKnWq1tMpsJY=; b=OuDNc2AYsBqN 1LCAGElI1C7YIT6M3tYdNjFlaKJSUjOuqs2tXD26ovPFiyWIVyl6dAW4Ccjhvw+p FP8oZmQF7hq0JflII/oxiWgBkuYu8HnJKYOPaRhlrvNa5ZOYfTUEc1IhqPeBltRa v5XwQYCarpyILZXy4OOWcZAVmc9jlLhkNlErgsw40gVaQHmSGL39bwh0MGZ7Of05 mbzH7igtkjPmEtlxFghw2T/EctDLAnEHM+EjyQy51JonGOEILcAg+A8L/rZp33TY PLesqQSI/qX1O9eL6z5jcMTLrDFqrRmrJK1hvhUDsR3wjB8OeRRCsNzfKESmzgXs pzMu+PGing== ARC-Authentication-Results: i=1; mx5.messagingengine.com; arc=none (no signatures found); dkim=pass (2048-bit rsa key sha256) header.d=gmail.com header.i=@gmail.com header.b=t+1D/EmY x-bits=2048 x-keytype=rsa x-algorithm=sha256 x-selector=20161025; dmarc=pass (p=none,has-list-id=yes,d=none) header.from=gmail.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-google-dkim=pass (2048-bit rsa key) header.d=1e100.net header.i=@1e100.net header.b=jtoLb3e7; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=gmail.com header.result=pass header_is_org_domain=yes Authentication-Results: mx5.messagingengine.com; arc=none (no signatures found); dkim=pass (2048-bit rsa key sha256) header.d=gmail.com header.i=@gmail.com header.b=t+1D/EmY x-bits=2048 x-keytype=rsa x-algorithm=sha256 x-selector=20161025; dmarc=pass (p=none,has-list-id=yes,d=none) header.from=gmail.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-google-dkim=pass (2048-bit rsa key) header.d=1e100.net header.i=@1e100.net header.b=jtoLb3e7; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=gmail.com header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752190AbeASXRU (ORCPT ); Fri, 19 Jan 2018 18:17:20 -0500 Received: from mail-io0-f195.google.com ([209.85.223.195]:33847 "EHLO mail-io0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752184AbeASXRS (ORCPT ); Fri, 19 Jan 2018 18:17:18 -0500 X-Google-Smtp-Source: AH8x226/ygS95jDPufAPUi9VjixwlxkCcXQfbaPCxTWMhOkCgOk5v+y4kHQ8lpRTVYAGpdR3a49NuQ== From: Eric Biggers To: linux-nfs@vger.kernel.org, Trond Myklebust , Anna Schumaker Cc: keyrings@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, Eric Biggers , stable@vger.kernel.org Subject: [PATCH] NFS: reject request for id_legacy key without auxdata Date: Fri, 19 Jan 2018 15:15:34 -0800 Message-Id: <20180119231534.77293-1-ebiggers3@gmail.com> X-Mailer: git-send-email 2.16.0.rc1.238.g530d649a79-goog In-Reply-To: <001a113f932c93a1400563282ce8@google.com> References: <001a113f932c93a1400563282ce8@google.com> Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: From: Eric Biggers 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 Cc: # v3.4+ Signed-off-by: Eric Biggers --- fs/nfs/nfs4idmap.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/nfs/nfs4idmap.c b/fs/nfs/nfs4idmap.c index 30426c1a1bbd..22dc30a679a0 100644 --- a/fs/nfs/nfs4idmap.c +++ b/fs/nfs/nfs4idmap.c @@ -568,9 +568,13 @@ static int nfs_idmap_legacy_upcall(struct key_construction *cons, 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; -- 2.16.0.rc1.238.g530d649a79-goog