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=-7.5 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=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 5B0DBC43441 for ; Mon, 19 Nov 2018 16:53:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 24258206BA for ; Mon, 19 Nov 2018 16:53:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="ieFVlKpP" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 24258206BA Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403777AbeKTDRL (ORCPT ); Mon, 19 Nov 2018 22:17:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:55316 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403763AbeKTDRK (ORCPT ); Mon, 19 Nov 2018 22:17:10 -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 DB38C206BA; Mon, 19 Nov 2018 16:52:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1542646376; bh=oCuIaUkDSHONnDNSq/oYN9CfOiI1aQkqBfpR9yr5tzs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ieFVlKpPOlXFQbh7K0FWRoSNfAaQy0fGCXRK4XpCXCqNwpPl+0oY9i4e2U0xHmqXX q1qFPvYIQLmIrUfqllun4+Bigks42Smc52nFI/ad5S57EOiuoyOeSoPeTZaMmgY4if DEpdUKGgTvjOO302O5hJmVb2RMAL5dCbS7J2hlm8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+4e975615ca01f2277bdd@syzkaller.appspotmail.com, Kirill Tkhai , Miklos Szeredi Subject: [PATCH 4.9 18/83] fuse: Fix use-after-free in fuse_dev_do_read() Date: Mon, 19 Nov 2018 17:28:44 +0100 Message-Id: <20181119162615.550729416@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181119162612.046511542@linuxfoundation.org> References: <20181119162612.046511542@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kirill Tkhai commit bc78abbd55dd28e2287ec6d6502b842321a17c87 upstream. We may pick freed req in this way: [cpu0] [cpu1] fuse_dev_do_read() fuse_dev_do_write() list_move_tail(&req->list, ...); ... spin_unlock(&fpq->lock); ... ... request_end(fc, req); ... fuse_put_request(fc, req); if (test_bit(FR_INTERRUPTED, ...)) queue_interrupt(fiq, req); Fix that by keeping req alive until we finish all manipulations. Reported-by: syzbot+4e975615ca01f2277bdd@syzkaller.appspotmail.com Signed-off-by: Kirill Tkhai Signed-off-by: Miklos Szeredi Fixes: 46c34a348b0a ("fuse: no fc->lock for pqueue parts") Cc: # v4.2 Signed-off-by: Greg Kroah-Hartman --- fs/fuse/dev.c | 2 ++ 1 file changed, 2 insertions(+) --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1303,12 +1303,14 @@ static ssize_t fuse_dev_do_read(struct f goto out_end; } list_move_tail(&req->list, &fpq->processing); + __fuse_get_request(req); spin_unlock(&fpq->lock); set_bit(FR_SENT, &req->flags); /* matches barrier in request_wait_answer() */ smp_mb__after_atomic(); if (test_bit(FR_INTERRUPTED, &req->flags)) queue_interrupt(fiq, req); + fuse_put_request(fc, req); return reqsize;