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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E99EFC3ABC5 for ; Thu, 8 May 2025 07:53:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=9Ym5IsgJPELXlmxVUiqqeE5x95LD2/wvG6YGV47RIG4=; b=MANrng3NYJGizgCwWO0PrsQXtr vRpwZ0dNgOACBh4M7XYt7aXcD+nsqDkwsLJdIfxu7e/3QIMxvvF+5QXbzR53gg6874XYeYcvb/am8 zypt4QEsGOx1tvt6BEokXq4Dvz7w2ApPmFCFMoqyKNLqGCwGr+DR52442/Fot7rDRy/VDGDedmLo7 R9gmC+m7vfv1UArZ00OxOZxM2iIfZlry4b5sXitZr1zFCG0eWQRQ+RsBbU+2b81WsBqzisSWqNVKS ATACfbEjjwPB2ruF0pa5XZd2jQNz12vtgIq3GsYTCcrBXyXTUWwj40fgX32mwNUE8FyOPOQiRRi4F Dg//b63A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uCw49-000000002qd-1SJs; Thu, 08 May 2025 07:53:13 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uCw39-000000002hT-3JEO for kexec@lists.infradead.org; Thu, 08 May 2025 07:52:13 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1746690730; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=9Ym5IsgJPELXlmxVUiqqeE5x95LD2/wvG6YGV47RIG4=; b=NITlekQHLdBqlk+4AO8S+QnpF+B5kl5KVxT2INqH/LxlkRNSLdnrsLNSwE8NWjaE9SI6Zo Qo397yRjRr0MNES9UZ9s5lWoQcenfRlR1Lp/SXNcctfq119ZSMR2MZZtNsZAdaayfj7+py zfc60PoxrsdCzH4hEs3T0UJc6Mu5JOg= Received: from mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-221-uoOCdMg9OBicCzW3qE3Qrw-1; Thu, 08 May 2025 03:52:09 -0400 X-MC-Unique: uoOCdMg9OBicCzW3qE3Qrw-1 X-Mimecast-MFC-AGG-ID: uoOCdMg9OBicCzW3qE3Qrw_1746690728 Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 396331956089; Thu, 8 May 2025 07:52:08 +0000 (UTC) Received: from localhost (unknown [10.72.112.8]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8A9551955F24; Thu, 8 May 2025 07:52:06 +0000 (UTC) Date: Thu, 8 May 2025 15:52:01 +0800 From: Baoquan He To: fuqiang wang Cc: Vivek Goyal , Dave Young , kexec@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5] x86/kexec: fix potential cmem->ranges out of bounds Message-ID: References: <20240108130720.228478-1-fuqiang.wang@easystack.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250508_005211_909202_195D870A X-CRM114-Status: GOOD ( 27.48 ) X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org On 05/08/25 at 03:38pm, Baoquan He wrote: > In memmap_exclude_ranges(), elfheader will be excluded from crashk_res. > In the current x86 architecture code, the elfheader is always allocated > at crashk_res.start. It seems that there won't be a new split range. > But it depends on the allocation position of elfheader in crashk_res. To > avoid potential out of bounds in future, add a extra slot. And using > random kexec_buf for passing dm crypt keys may cause a range split too, > add another extra slot here. Sorry, this should be from fuqiang wang, when I edited the patch to reply to his patch, I forgot that. Please help makes change to set Fuqiang as the patch author, I just adapted the content based on Coiby's patches. > > The similar issue also exists in fill_up_crash_elf_data(). The range to > be excluded is [0, 1M], start (0) is special and will not appear in the > middle of existing cmem->ranges[]. But in cast the low 1M could be > changed in the future, add a extra slot too. > > Previously discussed link: > [1] https://lore.kernel.org/kexec/ZXk2oBf%2FT1Ul6o0c@MiWiFi-R3L-srv/ > [2] https://lore.kernel.org/kexec/273284e8-7680-4f5f-8065-c5d780987e59@easystack.cn/ > [3] https://lore.kernel.org/kexec/ZYQ6O%2F57sHAPxTHm@MiWiFi-R3L-srv/ > > Signed-off-by: fuqiang wang > Signed-off-by: Baoquan He > --- > v4->v5: > - This is on top of Coiby's LUKS patchset in branch mm-nonmm-unstable of > akpm/mm.git. I did some adaption based on Coiby's patches. > - [PATCH v9 0/8] Support kdump with LUKS encryption by reusing LUKS volume keys > > arch/x86/kernel/crash.c | 23 +++++++++++++++++++---- > 1 file changed, 19 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c > index bcb534688dfe..749a60ce8b7f 100644 > --- a/arch/x86/kernel/crash.c > +++ b/arch/x86/kernel/crash.c > @@ -165,8 +165,18 @@ static struct crash_mem *fill_up_crash_elf_data(void) > /* > * Exclusion of crash region and/or crashk_low_res may cause > * another range split. So add extra two slots here. > + * > + * Exclusion of low 1M may not cause another range split, because the > + * range of exclude is [0, 1M] and the condition for splitting a new > + * region is that the start, end parameters are both in a certain > + * existing region in cmem and cannot be equal to existing region's > + * start or end. Obviously, the start of [0, 1M] cannot meet this > + * condition. > + * > + * But in order to lest the low 1M could be changed in the future, > + * (e.g. [stare, 1M]), add a extra slot. > */ > - nr_ranges += 2; > + nr_ranges += 3; > cmem = vzalloc(struct_size(cmem, ranges, nr_ranges)); > if (!cmem) > return NULL; > @@ -313,10 +323,15 @@ int crash_setup_memmap_entries(struct kimage *image, struct boot_params *params) > struct crash_mem *cmem; > > /* > - * Using random kexec_buf for passing dm crypt keys may cause a range > - * split. So use two slots here. > + * In the current x86 architecture code, the elfheader is always > + * allocated at crashk_res.start. But it depends on the allocation > + * position of elfheader in crashk_res. To avoid potential out of > + * bounds in future, add an extra slot. > + * > + * And using random kexec_buf for passing dm crypt keys may cause a > + * range split too, add another extra slot here. > */ > - nr_ranges = 2; > + nr_ranges = 3; > cmem = vzalloc(struct_size(cmem, ranges, nr_ranges)); > if (!cmem) > return -ENOMEM; > -- > 2.41.0 >