From patchwork Mon Jan 24 18:35:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 535408 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 A4826C4332F for ; Mon, 24 Jan 2022 21:38:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343517AbiAXVhG (ORCPT ); Mon, 24 Jan 2022 16:37:06 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:34740 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1447700AbiAXVLT (ORCPT ); Mon, 24 Jan 2022 16:11:19 -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 dfw.source.kernel.org (Postfix) with ESMTPS id B5A9B60C60; Mon, 24 Jan 2022 21:11:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 77ABBC340E8; Mon, 24 Jan 2022 21:11:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643058678; bh=ywvwEwdbHU5wOPoIxh/ANzlr4vblBlzIaHREvpeMLtM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CMNddaEn+ze8RCt3al5tdxZ23GZPcgQeGMqI4TmKhD5ScQwhZTbjxltfVZJ6kaM/L Znu/obZHuV/W9ktRFMf7FfErT2A2YH2JcoLI1oqMRYOQgzDhtCBp70gHNoIuulGtwO qz4ZY5fxpqhDuvvJtxl2fRpCbR0XRG7l9fX7/Yeg= 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 5.16 0365/1039] pcmcia: rsrc_nonstatic: Fix a NULL pointer dereference in __nonstatic_find_io_region() Date: Mon, 24 Jan 2022 19:35:54 +0100 Message-Id: <20220124184137.551740940@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124184125.121143506@linuxfoundation.org> References: <20220124184125.121143506@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@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 bb15a8bdbaab5..827ca6e9ee54a 100644 --- a/drivers/pcmcia/rsrc_nonstatic.c +++ b/drivers/pcmcia/rsrc_nonstatic.c @@ -690,6 +690,9 @@ 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;