From patchwork Fri Mar 13 15:21:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Waiman Long X-Patchwork-Id: 11437095 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4652616B1 for ; Fri, 13 Mar 2020 15:21:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 25AAC2074F for ; Fri, 13 Mar 2020 15:21:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="cbWP3/dz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726964AbgCMPVg (ORCPT ); Fri, 13 Mar 2020 11:21:36 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:24951 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726930AbgCMPVf (ORCPT ); Fri, 13 Mar 2020 11:21:35 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1584112894; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:in-reply-to:in-reply-to:references:references; bh=Guy49jz/MclwiKRYm/R98tQ5vcDgMGGlebOY5cev/kE=; b=cbWP3/dzBMAID5PrHP4UrOXqg8FeKgrsiMHZCQgR5jXOOOARuG7jl4DquqpLnUZKHrfgwC 1jVe4Utt1p/swYLfl2/46K3TY13FbW6GLktAS09mwDLDLL58r3CCnimygxPkXSg527bTWU hgskuju5J0dzQP/lbHw18ZV4Q7zUpuA= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-5-VNOdMdZHMWGwBA7EAb8cFg-1; Fri, 13 Mar 2020 11:21:32 -0400 X-MC-Unique: VNOdMdZHMWGwBA7EAb8cFg-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4E882808245; Fri, 13 Mar 2020 15:21:30 +0000 (UTC) Received: from llong.com (ovpn-125-21.rdu2.redhat.com [10.10.125.21]) by smtp.corp.redhat.com (Postfix) with ESMTP id 46A8291D61; Fri, 13 Mar 2020 15:21:28 +0000 (UTC) From: Waiman Long To: David Howells , Jarkko Sakkinen , James Morris , "Serge E. Hallyn" , Mimi Zohar Cc: keyrings@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, linux-integrity@vger.kernel.org, Sumit Garg , Jerry Snitselaar , Roberto Sassu , Eric Biggers , Chris von Recklinghausen , Waiman Long Subject: [PATCH v3 3/3] KEYS: Use kvmalloc() to better handle large buffer allocation Date: Fri, 13 Mar 2020 11:21:02 -0400 Message-Id: <20200313152102.1707-4-longman@redhat.com> In-Reply-To: <20200313152102.1707-1-longman@redhat.com> References: <20200313152102.1707-1-longman@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: For large multi-page temporary buffer allocation, the security/keys subsystem don't need contiguous physical pages. It will work perfectly fine with virtually mapped pages. Replace the kmalloc() call by kvmalloc() and provide a __kvzfree() helper function to clear and free the kvmalloc'ed buffer. This will reduce the chance of memory allocation failure just because of highly fragmented pages. Suggested-by: David Howells Signed-off-by: Waiman Long --- security/keys/internal.h | 14 ++++++++++++++ security/keys/keyctl.c | 10 +++++----- 2 files changed, 19 insertions(+), 5 deletions(-) diff --git a/security/keys/internal.h b/security/keys/internal.h index ba3e2da14cef..855b11eb73ee 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -16,6 +16,8 @@ #include #include #include +#include +#include struct iovec; @@ -349,4 +351,16 @@ static inline void key_check(const struct key *key) #endif +/* + * Helper function to clear and free a kvmalloc'ed memory object. + */ +static inline void __kvzfree(const void *addr, size_t len) +{ + if (is_vmalloc_addr(addr)) { + memset((void *)addr, 0, len); + vfree(addr); + } else { + kzfree(addr); + } +} #endif /* _INTERNAL_H */ diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c index a05a4dd2f9ce..878259cf35d5 100644 --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -339,7 +339,7 @@ long keyctl_update_key(key_serial_t id, payload = NULL; if (plen) { ret = -ENOMEM; - payload = kmalloc(plen, GFP_KERNEL); + payload = kvmalloc(plen, GFP_KERNEL); if (!payload) goto error; @@ -360,7 +360,7 @@ long keyctl_update_key(key_serial_t id, key_ref_put(key_ref); error2: - kzfree(payload); + __kvzfree(payload, plen); error: return ret; } @@ -893,7 +893,7 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) */ if (buflen <= 0x400) { allocbuf: - tmpbuf = kmalloc(tmpbuflen, GFP_KERNEL); + tmpbuf = kvmalloc(tmpbuflen, GFP_KERNEL); if (!tmpbuf) { ret = -ENOMEM; goto error2; @@ -911,7 +911,7 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) */ if (!tmpbuf || unlikely(ret > tmpbuflen)) { if (unlikely(tmpbuf)) - kzfree(tmpbuf); + __kvzfree(tmpbuf, tmpbuflen); tmpbuflen = ret; goto allocbuf; } @@ -920,7 +920,7 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen) ret = -EFAULT; } if (tmpbuf) - kzfree(tmpbuf); + __kvzfree(tmpbuf, tmpbuflen); } error2: