From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751909AbeERQ1p (ORCPT ); Fri, 18 May 2018 12:27:45 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:50816 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750763AbeERQ1l (ORCPT ); Fri, 18 May 2018 12:27:41 -0400 Date: Fri, 18 May 2018 18:27:39 +0200 From: Oleg Nesterov To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, syzbot , Masami Hiramatsu Subject: [PATCH] uprobes/x86: remove the wrong WARN_ON() in uprobe_init_insn() Message-ID: <20180518162739.GA5559@redhat.com> References: <000000000000b759cf056c2b3c12@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <000000000000b759cf056c2b3c12@google.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- arch/x86/kernel/uprobes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index 85c7ef2..efd7ee9 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -293,7 +293,7 @@ static int uprobe_init_insn(struct arch_uprobe *auprobe, struct insn *insn, bool 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)) -- 2.5.0