Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754013AbaGKR1M (ORCPT ); Fri, 11 Jul 2014 13:27:12 -0400 Received: from mail-pa0-f43.google.com ([209.85.220.43]:42731 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750896AbaGKR1L (ORCPT ); Fri, 11 Jul 2014 13:27:11 -0400 From: Andy Lutomirski To: Ingo Molnar , x86@kernel.org, linux-kernel@vger.kernel.org, Masami Hiramatsu Cc: Andy Lutomirski Subject: [PATCH v2 3.16] x86,kprobes: Don't try to resolve kprobe faults from userspace Date: Fri, 11 Jul 2014 10:27:01 -0700 Message-Id: X-Mailer: git-send-email 1.9.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This commit: commit 6f6343f53d133bae516caf3d254bce37d8774625 Author: Masami Hiramatsu Date: Thu Apr 17 17:17:33 2014 +0900 kprobes/x86: Call exception handlers directly from do_int3/do_debug appears to have inadvertently dropped a check that the int3 came from kernel mode. Trying to dereference addr when addr is user-controlled is completely bogus. Signed-off-by: Andy Lutomirski --- Changes from v1: Fixed the changelog message arch/x86/kernel/kprobes/core.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 7596df6..67e6d19 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -574,6 +574,9 @@ int kprobe_int3_handler(struct pt_regs *regs) struct kprobe *p; struct kprobe_ctlblk *kcb; + if (user_mode_vm(regs)) + return 0; + addr = (kprobe_opcode_t *)(regs->ip - sizeof(kprobe_opcode_t)); /* * We don't want to be preempted for the entire -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/