From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f72.google.com (mail-pg0-f72.google.com [74.125.83.72]) by kanga.kvack.org (Postfix) with ESMTP id 58FF66B028B for ; Thu, 7 Jun 2018 10:41:35 -0400 (EDT) Received: by mail-pg0-f72.google.com with SMTP id e1-v6so3584338pgp.20 for ; Thu, 07 Jun 2018 07:41:35 -0700 (PDT) Received: from mga05.intel.com (mga05.intel.com. [192.55.52.43]) by mx.google.com with ESMTPS id i74-v6si8716254pgc.188.2018.06.07.07.41.34 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 07 Jun 2018 07:41:34 -0700 (PDT) From: Yu-cheng Yu Subject: [PATCH 08/10] mm: Prevent mremap of shadow stack Date: Thu, 7 Jun 2018 07:38:05 -0700 Message-Id: <20180607143807.3611-9-yu-cheng.yu@intel.com> In-Reply-To: <20180607143807.3611-1-yu-cheng.yu@intel.com> References: <20180607143807.3611-1-yu-cheng.yu@intel.com> Sender: owner-linux-mm@kvack.org List-ID: 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 Signed-off-by: Yu-cheng Yu --- mm/mremap.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/mm/mremap.c b/mm/mremap.c index 049470aa1e3e..70f20edb248e 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -525,7 +525,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, unsigned long, new_addr) { struct mm_struct *mm = current->mm; - struct vm_area_struct *vma; + struct vm_area_struct *vma = find_vma(mm, addr); unsigned long ret = -EINVAL; unsigned long charged = 0; bool locked = false; @@ -533,6 +533,9 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len, LIST_HEAD(uf_unmap_early); LIST_HEAD(uf_unmap); + if (vma->vm_flags & VM_SHSTK) + return ret; + if (flags & ~(MREMAP_FIXED | MREMAP_MAYMOVE)) return ret; -- 2.15.1