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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 75A3CC433EF for ; Mon, 27 Jun 2022 11:49:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238027AbiF0Lto (ORCPT ); Mon, 27 Jun 2022 07:49:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48136 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238294AbiF0LsN (ORCPT ); Mon, 27 Jun 2022 07:48:13 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DFB41BE11; Mon, 27 Jun 2022 04:40:16 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 722DB6116D; Mon, 27 Jun 2022 11:40:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 840AAC3411D; Mon, 27 Jun 2022 11:40:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1656330015; bh=Xor3HCIQgPPTgGQZTK87IPF4nyQEx5tohD35dHjWbPw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LtQDA3Nc9kqFVRGH+DNyKIMgyoTN91re+cGw5TFxlCP5ds5HcXYv4nVeVvtzsKtf9 J8yiaRt4VWaOrD1n2+IiigDC5RRm8KwAnN5gRNCUU5wZG4K6SvDUIurT2ZKeqdOkGK 7hPkCYaiSmlnsXC7DSWLPCEOAYpwDsUiB+iJv/rY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mike Rapoport , Quentin Perret , Catalin Marinas , Marc Zyngier , Sasha Levin Subject: [PATCH 5.18 056/181] KVM: arm64: Prevent kmemleak from accessing pKVM memory Date: Mon, 27 Jun 2022 13:20:29 +0200 Message-Id: <20220627111946.191359304@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220627111944.553492442@linuxfoundation.org> References: <20220627111944.553492442@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Quentin Perret [ Upstream commit 56961c6331463cce2d84d0f973177a517fb33a82 ] Commit a7259df76702 ("memblock: make memblock_find_in_range method private") changed the API using which memory is reserved for the pKVM hypervisor. However, memblock_phys_alloc() differs from the original API in terms of kmemleak semantics -- the old one didn't report the reserved regions to kmemleak while the new one does. Unfortunately, when protected KVM is enabled, all kernel accesses to pKVM-private memory result in a fatal exception, which can now happen because of kmemleak scans: $ echo scan > /sys/kernel/debug/kmemleak [ 34.991354] kvm [304]: nVHE hyp BUG at: [] __kvm_nvhe_handle_host_mem_abort+0x270/0x290! [ 34.991580] kvm [304]: Hyp Offset: 0xfffe8be807e00000 [ 34.991813] Kernel panic - not syncing: HYP panic: [ 34.991813] PS:600003c9 PC:0000f418011a3750 ESR:00000000f2000800 [ 34.991813] FAR:ffff000439200000 HPFAR:0000000004792000 PAR:0000000000000000 [ 34.991813] VCPU:0000000000000000 [ 34.993660] CPU: 0 PID: 304 Comm: bash Not tainted 5.19.0-rc2 #102 [ 34.994059] Hardware name: linux,dummy-virt (DT) [ 34.994452] Call trace: [ 34.994641] dump_backtrace.part.0+0xcc/0xe0 [ 34.994932] show_stack+0x18/0x6c [ 34.995094] dump_stack_lvl+0x68/0x84 [ 34.995276] dump_stack+0x18/0x34 [ 34.995484] panic+0x16c/0x354 [ 34.995673] __hyp_pgtable_total_pages+0x0/0x60 [ 34.995933] scan_block+0x74/0x12c [ 34.996129] scan_gray_list+0xd8/0x19c [ 34.996332] kmemleak_scan+0x2c8/0x580 [ 34.996535] kmemleak_write+0x340/0x4a0 [ 34.996744] full_proxy_write+0x60/0xbc [ 34.996967] vfs_write+0xc4/0x2b0 [ 34.997136] ksys_write+0x68/0xf4 [ 34.997311] __arm64_sys_write+0x20/0x2c [ 34.997532] invoke_syscall+0x48/0x114 [ 34.997779] el0_svc_common.constprop.0+0x44/0xec [ 34.998029] do_el0_svc+0x2c/0xc0 [ 34.998205] el0_svc+0x2c/0x84 [ 34.998421] el0t_64_sync_handler+0xf4/0x100 [ 34.998653] el0t_64_sync+0x18c/0x190 [ 34.999252] SMP: stopping secondary CPUs [ 35.000034] Kernel Offset: disabled [ 35.000261] CPU features: 0x800,00007831,00001086 [ 35.000642] Memory Limit: none [ 35.001329] ---[ end Kernel panic - not syncing: HYP panic: [ 35.001329] PS:600003c9 PC:0000f418011a3750 ESR:00000000f2000800 [ 35.001329] FAR:ffff000439200000 HPFAR:0000000004792000 PAR:0000000000000000 [ 35.001329] VCPU:0000000000000000 ]--- Fix this by explicitly excluding the hypervisor's memory pool from kmemleak like we already do for the hyp BSS. Cc: Mike Rapoport Fixes: a7259df76702 ("memblock: make memblock_find_in_range method private") Signed-off-by: Quentin Perret Acked-by: Catalin Marinas Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220616161135.3997786-1-qperret@google.com Signed-off-by: Sasha Levin --- arch/arm64/kvm/arm.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index a66d83540c15..f88919a793ad 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -2011,11 +2011,11 @@ static int finalize_hyp_mode(void) return 0; /* - * Exclude HYP BSS from kmemleak so that it doesn't get peeked - * at, which would end badly once the section is inaccessible. - * None of other sections should ever be introspected. + * Exclude HYP sections from kmemleak so that they don't get peeked + * at, which would end badly once inaccessible. */ kmemleak_free_part(__hyp_bss_start, __hyp_bss_end - __hyp_bss_start); + kmemleak_free_part(__va(hyp_mem_base), hyp_mem_size); return pkvm_drop_host_privileges(); } -- 2.35.1