From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:50704 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756138AbdDRMu4 (ORCPT ); Tue, 18 Apr 2017 08:50:56 -0400 Subject: Patch "x86/vdso: Ensure vdso32_enabled gets set to valid values only" has been added to the 4.9-stable tree To: minipli@googlemail.com, gregkh@linuxfoundation.org, luto@amacapital.net, peterz@infradead.org, roland@redhat.com, tglx@linutronix.de Cc: , From: Date: Tue, 18 Apr 2017 14:50:35 +0200 Message-ID: <1492519835155107@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled x86/vdso: Ensure vdso32_enabled gets set to valid values only to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-vdso-ensure-vdso32_enabled-gets-set-to-valid-values-only.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From c06989da39cdb10604d572c8c7ea8c8c97f3c483 Mon Sep 17 00:00:00 2001 From: Mathias Krause Date: Mon, 10 Apr 2017 17:14:27 +0200 Subject: x86/vdso: Ensure vdso32_enabled gets set to valid values only From: Mathias Krause commit c06989da39cdb10604d572c8c7ea8c8c97f3c483 upstream. vdso_enabled can be set to arbitrary integer values via the kernel command line 'vdso32=' parameter or via 'sysctl abi.vsyscall32'. load_vdso32() only maps VDSO if vdso_enabled == 1, but ARCH_DLINFO_IA32 merily checks for vdso_enabled != 0. As a consequence the AT_SYSINFO_EHDR auxiliary vector for the VDSO_ENTRY is emitted with a NULL pointer which causes a segfault when the application tries to use the VDSO. Restrict the valid arguments on the command line and the sysctl to 0 and 1. Fixes: b0b49f2673f0 ("x86, vdso: Remove compat vdso support") Signed-off-by: Mathias Krause Acked-by: Andy Lutomirski Cc: Peter Zijlstra Cc: Roland McGrath Link: http://lkml.kernel.org/r/1491424561-7187-1-git-send-email-minipli@googlemail.com Link: http://lkml.kernel.org/r/20170410151723.518412863@linutronix.de Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- arch/x86/entry/vdso/vdso32-setup.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- a/arch/x86/entry/vdso/vdso32-setup.c +++ b/arch/x86/entry/vdso/vdso32-setup.c @@ -30,8 +30,10 @@ static int __init vdso32_setup(char *s) { vdso32_enabled = simple_strtoul(s, NULL, 0); - if (vdso32_enabled > 1) + if (vdso32_enabled > 1) { pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n"); + vdso32_enabled = 0; + } return 1; } @@ -62,13 +64,18 @@ subsys_initcall(sysenter_setup); /* Register vsyscall32 into the ABI table */ #include +static const int zero; +static const int one = 1; + static struct ctl_table abi_table2[] = { { .procname = "vsyscall32", .data = &vdso32_enabled, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec + .proc_handler = proc_dointvec_minmax, + .extra1 = (int *)&zero, + .extra2 = (int *)&one, }, {} }; Patches currently in stable-queue which might be from minipli@googlemail.com are queue-4.9/x86-vdso-ensure-vdso32_enabled-gets-set-to-valid-values-only.patch queue-4.9/x86-vdso-plug-race-between-mapping-and-elf-header-setup.patch