From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F24BFC3A5A2 for ; Fri, 20 Sep 2019 14:32:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C47972080F for ; Fri, 20 Sep 2019 14:32:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728366AbfITOcy (ORCPT ); Fri, 20 Sep 2019 10:32:54 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:36464 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388272AbfITOZJ (ORCPT ); Fri, 20 Sep 2019 10:25:09 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iBJqN-00051J-EL; Fri, 20 Sep 2019 15:25:07 +0100 Received: from ben by deadeye with local (Exim 4.92.1) (envelope-from ) id 1iBJqG-0007wB-Bh; Fri, 20 Sep 2019 15:25:00 +0100 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, Denis Kirjanov , "Dan Carpenter" , "Daniel Thompson" , "Douglas Anderson" Date: Fri, 20 Sep 2019 15:23:35 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 094/132] kdb: do a sanity check on the cpu in kdb_per_cpu() In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 3.16.74-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter commit b586627e10f57ee3aa8f0cfab0d6f7dc4ae63760 upstream. The "whichcpu" comes from argv[3]. The cpu_online() macro looks up the cpu in a bitmap of online cpus, but if the value is too high then it could read beyond the end of the bitmap and possibly Oops. Fixes: 5d5314d6795f ("kdb: core for kgdb back end (1 of 2)") Signed-off-by: Dan Carpenter Reviewed-by: Douglas Anderson Signed-off-by: Daniel Thompson Signed-off-by: Ben Hutchings --- kernel/debug/kdb/kdb_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -2569,7 +2569,7 @@ static int kdb_per_cpu(int argc, const c diag = kdbgetularg(argv[3], &whichcpu); if (diag) return diag; - if (!cpu_online(whichcpu)) { + if (whichcpu >= nr_cpu_ids || !cpu_online(whichcpu)) { kdb_printf("cpu %ld is not online\n", whichcpu); return KDB_BADCPUNUM; }