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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D96F7C433F5 for ; Mon, 24 Jan 2022 19:06:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346006AbiAXTEz (ORCPT ); Mon, 24 Jan 2022 14:04:55 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:55930 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344568AbiAXS6F (ORCPT ); Mon, 24 Jan 2022 13:58:05 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 32804B8124B; Mon, 24 Jan 2022 18:58:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 14570C340E7; Mon, 24 Jan 2022 18:58:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643050682; bh=IyEZm5VJ9DTUvGD5ch3pdHZ+oyGhrNtAXW8JkE7kfH0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vH8qIMtzoL8JA/VQ/vI6GvytJJPsr43Qbt7FlRxLpZl5SkHZ3kixjchVrLFwVV2ib Gp51JgB6skfbOgZ/h1TxCiT2agl2AkWKE0/vXyll9mwnNqy206hXa8fMB4DTsNG+Qk B5RPyAKZJedxmvw1iyYVBgNua11RNDW9OgVlJp1I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zhou Qingyang , Dominik Brodowski , Sasha Levin Subject: [PATCH 4.9 047/157] pcmcia: rsrc_nonstatic: Fix a NULL pointer dereference in __nonstatic_find_io_region() Date: Mon, 24 Jan 2022 19:42:17 +0100 Message-Id: <20220124183934.283948361@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124183932.787526760@linuxfoundation.org> References: <20220124183932.787526760@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Zhou Qingyang [ Upstream commit ca0fe0d7c35c97528bdf621fdca75f13157c27af ] In __nonstatic_find_io_region(), pcmcia_make_resource() is assigned to res and used in pci_bus_alloc_resource(). There is a dereference of res in pci_bus_alloc_resource(), which could lead to a NULL pointer dereference on failure of pcmcia_make_resource(). Fix this bug by adding a check of res. This bug was found by a static analyzer. The analysis employs differential checking to identify inconsistent security operations (e.g., checks or kfrees) between two code paths and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs. Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug. Builds with CONFIG_PCCARD_NONSTATIC=y show no new warnings, and our static analyzer no longer warns about this code. Fixes: 49b1153adfe1 ("pcmcia: move all pcmcia_resource_ops providers into one module") Signed-off-by: Zhou Qingyang [linux@dominikbrodowski.net: Fix typo in commit message] Signed-off-by: Dominik Brodowski Signed-off-by: Sasha Levin --- drivers/pcmcia/rsrc_nonstatic.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/pcmcia/rsrc_nonstatic.c b/drivers/pcmcia/rsrc_nonstatic.c index 5ef7b46a25786..4d244014f423f 100644 --- a/drivers/pcmcia/rsrc_nonstatic.c +++ b/drivers/pcmcia/rsrc_nonstatic.c @@ -693,6 +693,9 @@ static struct resource *__nonstatic_find_io_region(struct pcmcia_socket *s, unsigned long min = base; int ret; + if (!res) + return NULL; + data.mask = align - 1; data.offset = base & data.mask; data.map = &s_data->io_db; -- 2.34.1