From owner-dev-commits-src-all@freebsd.org Sat Jun 26 04:04:01 2021 Return-Path: Delivered-To: dev-commits-src-all@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id AB82A64AF84; Sat, 26 Jun 2021 04:04:01 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4GBgGn4Bpzz4pNk; Sat, 26 Jun 2021 04:04:01 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 7849B181AE; Sat, 26 Jun 2021 04:04:01 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 15Q441Sh042480; Sat, 26 Jun 2021 04:04:01 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 15Q441e2042479; Sat, 26 Jun 2021 04:04:01 GMT (envelope-from git) Date: Sat, 26 Jun 2021 04:04:01 GMT Message-Id: <202106260404.15Q441e2042479@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Alan Cox Subject: git: 5dd84e315a9f - main - arm64: fix a potential KVA leak in pmap_demote_l1() MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: alc X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 5dd84e315a9f777772017f9f628aa67f08a6493a Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-all@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for all branches of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 26 Jun 2021 04:04:01 -0000 The branch main has been updated by alc: URL: https://cgit.FreeBSD.org/src/commit/?id=5dd84e315a9f777772017f9f628aa67f08a6493a commit 5dd84e315a9f777772017f9f628aa67f08a6493a Author: Alan Cox AuthorDate: 2021-06-26 03:29:38 +0000 Commit: Alan Cox CommitDate: 2021-06-26 04:01:32 +0000 arm64: fix a potential KVA leak in pmap_demote_l1() In the unlikely event that the 1 GB page mapping being demoted is used to access the L1 page table page containing the 1 GB page mapping and the vm_page_alloc() to allocate a new L2 page table page fails, we would leak a page of kernel virtual address space. Fix this leak. MFC after: 1 week --- sys/arm64/arm64/pmap.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/sys/arm64/arm64/pmap.c b/sys/arm64/arm64/pmap.c index a6f716370810..76ca8eab70ff 100644 --- a/sys/arm64/arm64/pmap.c +++ b/sys/arm64/arm64/pmap.c @@ -6010,7 +6010,8 @@ pmap_demote_l1(pmap_t pmap, pt_entry_t *l1, vm_offset_t va) VM_ALLOC_NOOBJ | VM_ALLOC_WIRED)) == NULL) { CTR2(KTR_PMAP, "pmap_demote_l1: failure for va %#lx" " in pmap %p", va, pmap); - return (NULL); + l2 = NULL; + goto fail; } l2phys = VM_PAGE_TO_PHYS(ml2); @@ -6039,6 +6040,7 @@ pmap_demote_l1(pmap_t pmap, pt_entry_t *l1, vm_offset_t va) pmap_update_entry(pmap, l1, l2phys | L1_TABLE, va, PAGE_SIZE); +fail: if (tmpl1 != 0) { pmap_kremove(tmpl1); kva_free(tmpl1, PAGE_SIZE);