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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 9C9F7C169C4 for ; Mon, 11 Feb 2019 15:54:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5842D21B18 for ; Mon, 11 Feb 2019 15:54:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549900483; bh=JeuBIwNRYaeRrhrbmgxpqv2VqdDPAeqOUysVJ6GWBtY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=iue7CCXxCbiDqwr+MzdhsR1IdjGGcRW41QB+pQ8/ZTWXDTi7n2TgvUYHsrR4I7g5j +z2bLzR/H2W6GtRUIeXjsXtSVsMZfhbTxvpL5hxkPy3Yob6siox6YKCXvLX+jXNfcQ +zAhm1hGooHEtKHgARhY1rSMWjjLi4+4H78ro8os= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732476AbfBKPxo (ORCPT ); Mon, 11 Feb 2019 10:53:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:45486 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731236AbfBKOgZ (ORCPT ); Mon, 11 Feb 2019 09:36:25 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.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 710B420700; Mon, 11 Feb 2019 14:36:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549895784; bh=JeuBIwNRYaeRrhrbmgxpqv2VqdDPAeqOUysVJ6GWBtY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0d2/d1W8wItUZlQkvQhNlyMPWie82NZwoiFLX1/pLQh7J3+ftbZ+OohsA2GnX8Jst TDyHoBOHTJhr9nvJ8Gmy/KpaxEdGb+E2IG43QOLLt30fR58XwHXoIRJOjw7VT8+NEJ sIut2A9z9Ut7tqMxjEgVcmQccwWGFDFz7oqYiTmw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+c1e36d30ee3416289cc0@syzkaller.appspotmail.com, Miklos Szeredi Subject: [PATCH 4.20 322/352] fuse: handle zero sized retrieve correctly Date: Mon, 11 Feb 2019 15:19:09 +0100 Message-Id: <20190211141907.332307834@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190211141846.543045703@linuxfoundation.org> References: <20190211141846.543045703@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ From: Miklos Szeredi commit 97e1532ef81acb31c30f9e75bf00306c33a77812 upstream. Dereferencing req->page_descs[0] will Oops if req->max_pages is zero. Reported-by: syzbot+c1e36d30ee3416289cc0@syzkaller.appspotmail.com Tested-by: syzbot+c1e36d30ee3416289cc0@syzkaller.appspotmail.com Fixes: b2430d7567a3 ("fuse: add per-page descriptor to fuse_req") Cc: # v3.9 Signed-off-by: Miklos Szeredi Signed-off-by: Greg Kroah-Hartman --- fs/fuse/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1742,7 +1742,6 @@ static int fuse_retrieve(struct fuse_con req->in.h.nodeid = outarg->nodeid; req->in.numargs = 2; req->in.argpages = 1; - req->page_descs[0].offset = offset; req->end = fuse_retrieve_end; index = outarg->offset >> PAGE_SHIFT; @@ -1757,6 +1756,7 @@ static int fuse_retrieve(struct fuse_con this_num = min_t(unsigned, num, PAGE_SIZE - offset); req->pages[req->num_pages] = page; + req->page_descs[req->num_pages].offset = offset; req->page_descs[req->num_pages].length = this_num; req->num_pages++;