From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id EF3EF7D062 for ; Thu, 7 Jun 2018 15:42:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933959AbeFGPmE (ORCPT ); Thu, 7 Jun 2018 11:42:04 -0400 Received: from mga09.intel.com ([134.134.136.24]:36346 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933773AbeFGOlh (ORCPT ); Thu, 7 Jun 2018 10:41:37 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 07 Jun 2018 07:41:35 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,486,1520924400"; d="scan'208";a="62632664" Received: from 2b52.sc.intel.com ([143.183.136.51]) by orsmga001.jf.intel.com with ESMTP; 07 Jun 2018 07:41:34 -0700 From: Yu-cheng Yu To: linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , "H.J. Lu" , Vedvyas Shanbhogue , "Ravi V. Shankar" , Dave Hansen , Andy Lutomirski , Jonathan Corbet , Oleg Nesterov , Arnd Bergmann , Mike Kravetz Cc: Yu-cheng Yu Subject: [PATCH 10/10] mm: Prevent munmap and remap_file_pages of shadow stack Date: Thu, 7 Jun 2018 07:38:07 -0700 Message-Id: <20180607143807.3611-11-yu-cheng.yu@intel.com> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180607143807.3611-1-yu-cheng.yu@intel.com> References: <20180607143807.3611-1-yu-cheng.yu@intel.com> Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Signed-off-by: Yu-cheng Yu --- mm/mmap.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/mm/mmap.c b/mm/mmap.c index fc41c0543d7f..e7d1fcb7ec58 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2810,6 +2810,16 @@ EXPORT_SYMBOL(vm_munmap); SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) { + struct vm_area_struct *vma; + + /* Do not munmap shadow stack */ + down_read(¤t->mm->mmap_sem); + vma = find_vma(current->mm, addr); + if (vma && (vma->vm_flags & VM_SHSTK)) { + up_read(¤t->mm->mmap_sem); + return -EINVAL; + } + up_read(¤t->mm->mmap_sem); profile_munmap(addr); return vm_munmap(addr, len); } @@ -2851,6 +2861,9 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size, if (!vma || !(vma->vm_flags & VM_SHARED)) goto out; + if (vma->vm_flags & VM_SHSTK) + goto out; + if (start < vma->vm_start) goto out; -- 2.15.1 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html