From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:48344 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388443AbeGWNod (ORCPT ); Mon, 23 Jul 2018 09:44:33 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vineet Gupta Subject: [PATCH 4.4 006/107] ARC: mm: allow mprotect to make stack mappings executable Date: Mon, 23 Jul 2018 14:41:00 +0200 Message-Id: <20180723122413.238814123@linuxfoundation.org> In-Reply-To: <20180723122413.003644357@linuxfoundation.org> References: <20180723122413.003644357@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vineet Gupta commit 93312b6da4df31e4102ce5420e6217135a16c7ea upstream. mprotect(EXEC) was failing for stack mappings as default vm flags was missing MAYEXEC. This was triggered by glibc test suite nptl/tst-execstack testcase What is surprising is that despite running LTP for years on, we didn't catch this issue as it lacks a directed test case. gcc dejagnu tests with nested functions also requiring exec stack work fine though because they rely on the GNU_STACK segment spit out by compiler and handled in kernel elf loader. This glibc case is different as the stack is non exec to begin with and a dlopen of shared lib with GNU_STACK segment triggers the exec stack proceedings using a mprotect(PROT_EXEC) which was broken. CC: stable@vger.kernel.org Signed-off-by: Vineet Gupta Signed-off-by: Greg Kroah-Hartman --- arch/arc/include/asm/page.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arc/include/asm/page.h +++ b/arch/arc/include/asm/page.h @@ -102,7 +102,7 @@ typedef pte_t * pgtable_t; #define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT) /* Default Permissions for stack/heaps pages (Non Executable) */ -#define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE) +#define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC) #define WANT_PAGE_VIRTUAL 1