From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-23.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D2005C433E6 for ; Thu, 21 Jan 2021 17:38:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8FAFD22B2C for ; Thu, 21 Jan 2021 17:38:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388316AbhAURi1 (ORCPT ); Thu, 21 Jan 2021 12:38:27 -0500 Received: from linux.microsoft.com ([13.77.154.182]:58572 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731961AbhAURh6 (ORCPT ); Thu, 21 Jan 2021 12:37:58 -0500 Received: from sequoia (162-237-133-238.lightspeed.rcsntx.sbcglobal.net [162.237.133.238]) by linux.microsoft.com (Postfix) with ESMTPSA id 30AE920B7192; Thu, 21 Jan 2021 09:37:17 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 30AE920B7192 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1611250637; bh=fbcRcp3idFFWOwiOjLdBsLqpIczhr4t2xXWIs0rFOng=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Fmcd9KrwyIO9TqvZmr0jqA0gEJmzIDHUMnaPFQFbijMEsfENZEAaX5Xo++kbH58i2 agEegx67+IM2QDODuukFUevio4kE2yxldq9dWrZ+0CmuNgv6vejrdDnHKRZRE9PLqW uEJDWxGe0Mz7g7InS7KFcW/oXqQJKMMVZuGT+FUw= Date: Thu, 21 Jan 2021 11:37:15 -0600 From: Tyler Hicks To: Lakshmi Ramasubramanian Cc: zohar@linux.ibm.com, bauerman@linux.ibm.com, dmitry.kasatkin@gmail.com, ebiederm@xmission.com, gregkh@linuxfoundation.org, sashal@kernel.org, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH 2/2] ima: Free IMA measurement buffer after kexec syscall Message-ID: <20210121173715.GF259508@sequoia> References: <20210121173003.18324-1-nramas@linux.microsoft.com> <20210121173003.18324-2-nramas@linux.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210121173003.18324-2-nramas@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On 2021-01-21 09:30:03, Lakshmi Ramasubramanian wrote: > IMA allocates kernel virtual memory to carry forward the measurement > list, from the current kernel to the next kernel on kexec system call, > in ima_add_kexec_buffer() function. This buffer is not freed before > completing the kexec system call resulting in memory leak. > > Add ima_buffer field in "struct kimage" to store the virtual address > of the buffer allocated for the IMA measurement list. > Free the memory allocated for the IMA measurement list in > kimage_file_post_load_cleanup() function. > > Signed-off-by: Lakshmi Ramasubramanian > Suggested-by: Tyler Hicks > Fixes: 7b8589cc29e7 ("ima: on soft reboot, save the measurement list") Reviewed-by: Tyler Hicks Tyler > --- > include/linux/kexec.h | 5 +++++ > kernel/kexec_file.c | 5 +++++ > security/integrity/ima/ima_kexec.c | 2 ++ > 3 files changed, 12 insertions(+) > > diff --git a/include/linux/kexec.h b/include/linux/kexec.h > index 9e93bef52968..5f61389f5f36 100644 > --- a/include/linux/kexec.h > +++ b/include/linux/kexec.h > @@ -300,6 +300,11 @@ struct kimage { > /* Information for loading purgatory */ > struct purgatory_info purgatory_info; > #endif > + > +#ifdef CONFIG_IMA_KEXEC > + /* Virtual address of IMA measurement buffer for kexec syscall */ > + void *ima_buffer; > +#endif > }; > > /* kexec interface functions */ > diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c > index b02086d70492..5c3447cf7ad5 100644 > --- a/kernel/kexec_file.c > +++ b/kernel/kexec_file.c > @@ -166,6 +166,11 @@ void kimage_file_post_load_cleanup(struct kimage *image) > vfree(pi->sechdrs); > pi->sechdrs = NULL; > > +#ifdef CONFIG_IMA_KEXEC > + vfree(image->ima_buffer); > + image->ima_buffer = NULL; > +#endif /* CONFIG_IMA_KEXEC */ > + > /* See if architecture has anything to cleanup post load */ > arch_kimage_file_post_load_cleanup(image); > > diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c > index 212145008a01..8eadd0674629 100644 > --- a/security/integrity/ima/ima_kexec.c > +++ b/security/integrity/ima/ima_kexec.c > @@ -130,6 +130,8 @@ void ima_add_kexec_buffer(struct kimage *image) > return; > } > > + image->ima_buffer = kexec_buffer; > + > pr_debug("kexec measurement buffer for the loaded kernel at 0x%lx.\n", > kbuf.mem); > } > -- > 2.30.0 >