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,URIBL_BLOCKED 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 81271C433FF for ; Sat, 10 Aug 2019 20:51:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 615CD208C3 for ; Sat, 10 Aug 2019 20:51:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727660AbfHJUuz (ORCPT ); Sat, 10 Aug 2019 16:50:55 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:54362 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726688AbfHJUnz (ORCPT ); Sat, 10 Aug 2019 16:43:55 -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 1hwYDQ-00053u-5u; Sat, 10 Aug 2019 21:43:52 +0100 Received: from ben by deadeye with local (Exim 4.92) (envelope-from ) id 1hwYDN-0003ho-BT; Sat, 10 Aug 2019 21:43:49 +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 , syzbot+45474c076a4927533d2e@syzkaller.appspotmail.com, "Linus Torvalds" , "David Miller" Date: Sat, 10 Aug 2019 21:40:07 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 114/157] slip: make slhc_free() silently accept an error pointer 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: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.72-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Linus Torvalds commit baf76f0c58aec435a3a864075b8f6d8ee5d1f17e upstream. This way, slhc_free() accepts what slhc_init() returns, whether that is an error or not. In particular, the pattern in sl_alloc_bufs() is slcomp = slhc_init(16, 16); ... slhc_free(slcomp); for the error handling path, and rather than complicate that code, just make it ok to always free what was returned by the init function. That's what the code used to do before commit 4ab42d78e37a ("ppp, slip: Validate VJ compression slot parameters completely") when slhc_init() just returned NULL for the error case, with no actual indication of the details of the error. Reported-by: syzbot+45474c076a4927533d2e@syzkaller.appspotmail.com Fixes: 4ab42d78e37a ("ppp, slip: Validate VJ compression slot parameters completely") Acked-by: Ben Hutchings Cc: David Miller Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings --- drivers/net/slip/slhc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/net/slip/slhc.c +++ b/drivers/net/slip/slhc.c @@ -153,7 +153,7 @@ out_fail: void slhc_free(struct slcompress *comp) { - if ( comp == NULLSLCOMPR ) + if ( IS_ERR_OR_NULL(comp) ) return; if ( comp->tstate != NULLSLSTATE )