From patchwork Tue Jun 23 19:56:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 223433 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=-10.0 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 7EF38C433DF for ; Tue, 23 Jun 2020 20:37:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4F03321556 for ; Tue, 23 Jun 2020 20:37:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592944622; bh=PrCNUgQ/SXgMeIdcoc5Sk0/EeTIz7pOsb/IZl/fh8g4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1WsF3/DgDLiJ3xwMs9leyG4KaX0tmfirg2mM31OLTmNPqAgOdmRUqklf6jFVSrIKp 1tmP/nc92s9BEerrDeecltBUwudAMZYui3/kssffL6+xXhH87d3e7InpOpo6Mn+GCh R/g8uR8qy5wPVn4wyoebgPPFqWK0s1PpJD6lRE0w= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391843AbgFWUhA (ORCPT ); Tue, 23 Jun 2020 16:37:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:60274 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391264AbgFWUg7 (ORCPT ); Tue, 23 Jun 2020 16:36:59 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E577321527; Tue, 23 Jun 2020 20:36:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592944619; bh=PrCNUgQ/SXgMeIdcoc5Sk0/EeTIz7pOsb/IZl/fh8g4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j/kdxM1rLmmVPnp2wqKmt+i+Gj6W25a3CLYwj9HpYCuvQb08p9iI0fh6sFKSem1mm Od/UC/qPMDmekcdJRKhylWrna6JiQknp+x0KEY6P/NJt2ovW9wFx+wdnX0SQWiMm8A IBAZUDAyuZ+p0Te6Z5mGjb4/+XakIZkAta5EyZqk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xiyu Yang , Xin Tan , Sasha Levin Subject: [PATCH 4.19 058/206] staging: gasket: Fix mapping refcnt leak when register/store fails Date: Tue, 23 Jun 2020 21:56:26 +0200 Message-Id: <20200623195319.825470787@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200623195316.864547658@linuxfoundation.org> References: <20200623195316.864547658@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Xiyu Yang [ Upstream commit e3436ce60cf5f5eaedda2b8c622f69feb97595e2 ] gasket_sysfs_register_store() invokes get_mapping(), which returns a reference of the specified gasket_sysfs_mapping object to "mapping" with increased refcnt. When gasket_sysfs_register_store() returns, local variable "mapping" becomes invalid, so the refcount should be decreased to keep refcount balanced. The reference counting issue happens in one exception handling path of gasket_sysfs_register_store(). When gasket_dev is NULL, the function forgets to decrease the refcnt increased by get_mapping(), causing a refcnt leak. Fix this issue by calling put_mapping() when gasket_dev is NULL. Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan Link: https://lore.kernel.org/r/1587618941-13718-1-git-send-email-xiyuyang19@fudan.edu.cn Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/staging/gasket/gasket_sysfs.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/staging/gasket/gasket_sysfs.c b/drivers/staging/gasket/gasket_sysfs.c index 9c982f1c0881d..5986c67bc7ec3 100644 --- a/drivers/staging/gasket/gasket_sysfs.c +++ b/drivers/staging/gasket/gasket_sysfs.c @@ -377,6 +377,7 @@ ssize_t gasket_sysfs_register_store(struct device *device, gasket_dev = mapping->gasket_dev; if (!gasket_dev) { dev_err(device, "Device driver may have been removed\n"); + put_mapping(mapping); return 0; }