From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:36832 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728015AbeJNXUW (ORCPT ); Sun, 14 Oct 2018 19:20:22 -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, "=?UTF-8?Q?=E8=8C=83=E9=BE=99=E9=A3=9E?=" , security@kernel.org, "Peter Zijlstra" , "Masami Hiramatsu" , "Thomas Gleixner" , "Song Liu" , "Linus Torvalds" , "Ingo Molnar" Date: Sun, 14 Oct 2018 16:25:41 +0100 Message-ID: Subject: [PATCH 3.16 131/366] tracing/uprobe_event: Fix strncpy corner case In-Reply-To: Sender: stable-owner@vger.kernel.org List-ID: 3.16.60-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Masami Hiramatsu commit 50268a3d266ecfdd6c5873d62b2758d9732fc598 upstream. Fix string fetch function to terminate with NUL. It is OK to drop the rest of string. Signed-off-by: Masami Hiramatsu Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Song Liu Cc: Thomas Gleixner Cc: security@kernel.org Cc: 范龙飞 Fixes: 5baaa59ef09e ("tracing/probes: Implement 'memory' fetch method for uprobes") Signed-off-by: Ingo Molnar Signed-off-by: Ben Hutchings --- kernel/trace/trace_uprobe.c | 2 ++ 1 file changed, 2 insertions(+) --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -149,6 +149,8 @@ static void FETCH_FUNC_NAME(memory, stri return; ret = strncpy_from_user(dst, src, maxlen); + if (ret == maxlen) + dst[--ret] = '\0'; if (ret < 0) { /* Failed to fetch string */ ((u8 *)get_rloc_data(dest))[0] = '\0';