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=-17.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 E95CEC43461 for ; Wed, 7 Apr 2021 15:35:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C059C61284 for ; Wed, 7 Apr 2021 15:35:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243285AbhDGPfN (ORCPT ); Wed, 7 Apr 2021 11:35:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34358 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230248AbhDGPfJ (ORCPT ); Wed, 7 Apr 2021 11:35:09 -0400 Received: from fieldses.org (fieldses.org [IPv6:2600:3c00:e000:2f7::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 000AEC061756; Wed, 7 Apr 2021 08:34:59 -0700 (PDT) Received: by fieldses.org (Postfix, from userid 2815) id E5C6E6A45; Wed, 7 Apr 2021 11:34:58 -0400 (EDT) DKIM-Filter: OpenDKIM Filter v2.11.0 fieldses.org E5C6E6A45 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fieldses.org; s=default; t=1617809698; bh=bLQwzZC+bbhqKQBwwlTZfOUN0mKSee0/NQ+qVibG9tA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BxDWI9NjGmn6HGVSDiAJrvOjV3elqwdY183AU2UszAVMZ8YhXiuxCvN4Y8iDUZoqG dPnrzDbm+UF74K70EuqcAwDc3WO8Dl10+HR0kH2fJ9dDvJQWpjd0A5EnhF5YGkpQRU xG8nwVkN+xrMHVh/Y8zm9kFnu5LHNpgL8PYADcx4= Date: Wed, 7 Apr 2021 11:34:58 -0400 From: "J. Bruce Fields" To: Aditya Pakki Cc: Chuck Lever , Trond Myklebust , Anna Schumaker , "David S. Miller" , Jakub Kicinski , Dave Wysochanski , linux-nfs@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] SUNRPC: Add a check for gss_release_msg Message-ID: <20210407153458.GA28924@fieldses.org> References: <20210407001658.2208535-1-pakki001@umn.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210407001658.2208535-1-pakki001@umn.edu> User-Agent: Mutt/1.5.21 (2010-09-15) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 06, 2021 at 07:16:56PM -0500, Aditya Pakki wrote: > In gss_pipe_destroy_msg(), in case of error in msg, gss_release_msg > deletes gss_msg. The patch adds a check to avoid a potential double > free. We're already dereferenced msg. Nothing has set gss_msg to NULL. It's the gss_msg->count reference count that's supposed to prevent double frees. Did you see an actual bug or warning from some tool, and if so, could you share the details? --b. > > Signed-off-by: Aditya Pakki > --- > net/sunrpc/auth_gss/auth_gss.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c > index 5f42aa5fc612..eb52eebb3923 100644 > --- a/net/sunrpc/auth_gss/auth_gss.c > +++ b/net/sunrpc/auth_gss/auth_gss.c > @@ -848,7 +848,8 @@ gss_pipe_destroy_msg(struct rpc_pipe_msg *msg) > warn_gssd(); > gss_release_msg(gss_msg); > } > - gss_release_msg(gss_msg); > + if (gss_msg) > + gss_release_msg(gss_msg); > } > > static void gss_pipe_dentry_destroy(struct dentry *dir, > -- > 2.25.1