From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:50716 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752891AbdDRMu7 (ORCPT ); Tue, 18 Apr 2017 08:50:59 -0400 Subject: Patch "x86/vdso: Plug race between mapping and ELF header setup" has been added to the 4.9-stable tree To: tglx@linutronix.de, gregkh@linuxfoundation.org, luto@amacapital.net, minipli@googlemail.com, peterz@infradead.org Cc: , From: Date: Tue, 18 Apr 2017 14:50:37 +0200 Message-ID: <1492519837243110@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: Plug race between mapping and ELF header setup 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-plug-race-between-mapping-and-elf-header-setup.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 6fdc6dd90272ce7e75d744f71535cfbd8d77da81 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 10 Apr 2017 17:14:28 +0200 Subject: x86/vdso: Plug race between mapping and ELF header setup From: Thomas Gleixner commit 6fdc6dd90272ce7e75d744f71535cfbd8d77da81 upstream. The vsyscall32 sysctl can racy against a concurrent fork when it switches from disabled to enabled: arch_setup_additional_pages() if (vdso32_enabled) --> No mapping sysctl.vsysscall32() --> vdso32_enabled = true create_elf_tables() ARCH_DLINFO_IA32 if (vdso32_enabled) { --> Add VDSO entry with NULL pointer Make ARCH_DLINFO_IA32 check whether the VDSO mapping has been set up for the newly forked process or not. Signed-off-by: Thomas Gleixner Acked-by: Andy Lutomirski Cc: Peter Zijlstra Cc: Mathias Krause Link: http://lkml.kernel.org/r/20170410151723.602367196@linutronix.de Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/elf.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/include/asm/elf.h +++ b/arch/x86/include/asm/elf.h @@ -278,7 +278,7 @@ struct task_struct; #define ARCH_DLINFO_IA32 \ do { \ - if (vdso32_enabled) { \ + if (VDSO_CURRENT_BASE) { \ NEW_AUX_ENT(AT_SYSINFO, VDSO_ENTRY); \ NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_CURRENT_BASE); \ } \ Patches currently in stable-queue which might be from tglx@linutronix.de are queue-4.9/x86-efi-don-t-try-to-reserve-runtime-regions.patch queue-4.9/x86-signals-fix-lower-upper-bound-reporting-in-compat-siginfo.patch queue-4.9/x86-vdso-ensure-vdso32_enabled-gets-set-to-valid-values-only.patch queue-4.9/x86-pmem-fix-broken-__copy_user_nocache-cache-bypass-assumptions.patch queue-4.9/x86-vdso-plug-race-between-mapping-and-elf-header-setup.patch queue-4.9/cgroup-kthread-close-race-window-where-new-kthreads-can-be-migrated-to-non-root-cgroups.patch queue-4.9/perf-x86-avoid-exposing-wrong-stale-data-in-intel_pmu_lbr_read_32.patch