From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:48958 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388939AbeGPILV (ORCPT ); Mon, 16 Jul 2018 04:11:21 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+30d675e3ca03c1c351e7@syzkaller.appspotmail.com, Oleg Nesterov , Masami Hiramatsu , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , syzkaller-bugs@googlegroups.com, Ingo Molnar Subject: [PATCH 4.4 37/43] uprobes/x86: Remove incorrect WARN_ON() in uprobe_init_insn() Date: Mon, 16 Jul 2018 09:36:42 +0200 Message-Id: <20180716073515.996604764@linuxfoundation.org> In-Reply-To: <20180716073511.796555857@linuxfoundation.org> References: <20180716073511.796555857@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Oleg Nesterov commit 90718e32e1dcc2479acfa208ccfc6442850b594c upstream. insn_get_length() has the side-effect of processing the entire instruction but only if it was decoded successfully, otherwise insn_complete() can fail and in this case we need to just return an error without warning. Reported-by: syzbot+30d675e3ca03c1c351e7@syzkaller.appspotmail.com Signed-off-by: Oleg Nesterov Reviewed-by: Masami Hiramatsu Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: syzkaller-bugs@googlegroups.com Link: https://lkml.kernel.org/lkml/20180518162739.GA5559@redhat.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/uprobes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -290,7 +290,7 @@ static int uprobe_init_insn(struct arch_ insn_init(insn, auprobe->insn, sizeof(auprobe->insn), x86_64); /* has the side-effect of processing the entire instruction */ insn_get_length(insn); - if (WARN_ON_ONCE(!insn_complete(insn))) + if (!insn_complete(insn)) return -ENOEXEC; if (is_prefix_bad(insn))