From patchwork Mon Jan 24 18:42:14 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 536268 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 8229EC35273 for ; Mon, 24 Jan 2022 19:15:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237395AbiAXTPn (ORCPT ); Mon, 24 Jan 2022 14:15:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239892AbiAXTNT (ORCPT ); Mon, 24 Jan 2022 14:13:19 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0BCE5C061749; Mon, 24 Jan 2022 11:05:17 -0800 (PST) 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 9F0DC60E8D; Mon, 24 Jan 2022 19:05:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6C0E8C340E5; Mon, 24 Jan 2022 19:05:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643051116; bh=WwExldU9G39L2ssPdcPuqzKK5FM6hA2PmC/gQghHkmE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JIHHH5rDWiea/AorydXujGo/UeXikfW6eSUd+c16YOezyQZmCUvP7xEco5JbmhvJK Yw4Dqxb8gk8IY2ey70m556wG0vNpNTB9aAAZCrOC5b3vsg5HcYO6LJsZ7WJ37CMvY8 16F3EJYtLiZEF3WxfqvfWeY2kQxuz41dwv8cf1og= 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 4.14 059/186] pcmcia: rsrc_nonstatic: Fix a NULL pointer dereference in nonstatic_find_mem_region() Date: Mon, 24 Jan 2022 19:42:14 +0100 Message-Id: <20220124183939.025695500@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124183937.101330125@linuxfoundation.org> References: <20220124183937.101330125@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 977d2e7c63c3d04d07ba340b39987742e3241554 ] In nonstatic_find_mem_region(), pcmcia_make_resource() is assigned to res and used in pci_bus_alloc_resource(). There 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 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 4d244014f423f..2e96d9273b780 100644 --- a/drivers/pcmcia/rsrc_nonstatic.c +++ b/drivers/pcmcia/rsrc_nonstatic.c @@ -815,6 +815,9 @@ static struct resource *nonstatic_find_mem_region(u_long base, u_long num, unsigned long min, max; int ret, i, j; + if (!res) + return NULL; + low = low || !(s->features & SS_CAP_PAGE_REGS); data.mask = align - 1;