From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754632AbdJINBf (ORCPT ); Mon, 9 Oct 2017 09:01:35 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:41912 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754380AbdJIMpS (ORCPT ); Mon, 9 Oct 2017 08:45:18 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Arun Sharma" , "Ingo Molnar" , "Jann Horn" , "Linus Torvalds" , "Peter Zijlstra" Date: Mon, 09 Oct 2017 13:30:34 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 69/74] perf/x86: Check if user fp is valid In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.94-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Arun Sharma commit bc6ca7b342d5ae15c3ba3081fd40271b8039fb25 upstream. Signed-off-by: Arun Sharma Cc: Linus Torvalds Cc: linux-kernel@vger.kernel.org Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1334961696-19580-4-git-send-email-asharma@fb.com Signed-off-by: Ingo Molnar [bwh: Backported to 3.2: also add user_addr_max() macro] Cc: Jann Horn Signed-off-by: Ben Hutchings --- --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -32,9 +32,9 @@ #define segment_eq(a, b) ((a).seg == (b).seg) -#define __addr_ok(addr) \ - ((unsigned long __force)(addr) < \ - (current_thread_info()->addr_limit.seg)) +#define user_addr_max() (current_thread_info()->addr_limit.seg) +#define __addr_ok(addr) \ + ((unsigned long __force)(addr) < user_addr_max()) /* * Test whether a block of memory is a valid user space address. @@ -46,14 +46,14 @@ * This needs 33-bit (65-bit for x86_64) arithmetic. We have a carry... */ -#define __range_not_ok(addr, size) \ +#define __range_not_ok(addr, size, limit) \ ({ \ unsigned long flag, roksum; \ __chk_user_ptr(addr); \ asm("add %3,%1 ; sbb %0,%0 ; cmp %1,%4 ; sbb $0,%0" \ : "=&r" (flag), "=r" (roksum) \ : "1" (addr), "g" ((long)(size)), \ - "rm" (current_thread_info()->addr_limit.seg)); \ + "rm" (limit)); \ flag; \ }) @@ -76,7 +76,8 @@ * checks that the pointer is in the user space range - after calling * this function, memory access functions may still return -EFAULT. */ -#define access_ok(type, addr, size) (likely(__range_not_ok(addr, size) == 0)) +#define access_ok(type, addr, size) \ + (likely(__range_not_ok(addr, size, user_addr_max()) == 0)) /* * The exception table consists of pairs of addresses: the first is the --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -1461,6 +1461,12 @@ perf_callchain_kernel(struct perf_callch dump_trace(NULL, regs, NULL, 0, &backtrace_ops, entry); } +static inline int +valid_user_frame(const void __user *fp, unsigned long size) +{ + return (__range_not_ok(fp, size, TASK_SIZE) == 0); +} + #ifdef CONFIG_COMPAT static inline int perf_callchain_user32(struct pt_regs *regs, struct perf_callchain_entry *entry) @@ -1485,6 +1491,9 @@ perf_callchain_user32(struct pt_regs *re if (fp < compat_ptr(regs->sp)) break; + if (!valid_user_frame(fp, sizeof(frame))) + break; + perf_callchain_store(entry, frame.return_address); fp = compat_ptr(frame.next_frame); } @@ -1531,6 +1540,9 @@ perf_callchain_user(struct perf_callchai if ((unsigned long)fp < regs->sp) break; + if (!valid_user_frame(fp, sizeof(frame))) + break; + perf_callchain_store(entry, frame.return_address); fp = frame.next_frame; }