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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A1F74C32774 for ; Tue, 23 Aug 2022 12:11:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359365AbiHWML1 (ORCPT ); Tue, 23 Aug 2022 08:11:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35516 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1359520AbiHWMJP (ORCPT ); Tue, 23 Aug 2022 08:09:15 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9CD8959266; Tue, 23 Aug 2022 02:38:32 -0700 (PDT) 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 4501A612D6; Tue, 23 Aug 2022 09:38:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 344E6C433C1; Tue, 23 Aug 2022 09:38:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661247511; bh=w0p436ssZfj/lQdy31bDOBkJyI06WCHkjyGiFQ8EqOQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PyAwfbnKoetoX3kDDqPNtmM6PJZqgX9wXp+02b8rirOgLjnvSzZlbXT8juj/U8NrK cTmI06TDNKHZOY0WSTdbtpEiGOxJIrmpzMKFuduzloXW8GDTKYsetpMmQgOP59hesC I9sHWyBMNiimoUd5s4bBCZNI8Lnz2LgoUNvO9V9o= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Oleksandr Tyshchenko , Juergen Gross Subject: [PATCH 5.10 059/158] xen/xenbus: fix return type in xenbus_file_read() Date: Tue, 23 Aug 2022 10:26:31 +0200 Message-Id: <20220823080048.450524486@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080046.056825146@linuxfoundation.org> References: <20220823080046.056825146@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Dan Carpenter commit 32ad11127b95236dfc52375f3707853194a7f4b4 upstream. This code tries to store -EFAULT in an unsigned int. The xenbus_file_read() function returns type ssize_t so the negative value is returned as a positive value to the user. This change forces another change to the min() macro. Originally, the min() macro used "unsigned" type which checkpatch complains about. Also unsigned type would break if "len" were not capped at MAX_RW_COUNT. Use size_t for the min(). (No effect on runtime for the min_t() change). Fixes: 2fb3683e7b16 ("xen: Add xenbus device driver") Signed-off-by: Dan Carpenter Reviewed-by: Oleksandr Tyshchenko Link: https://lore.kernel.org/r/YutxJUaUYRG/VLVc@kili Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman --- drivers/xen/xenbus/xenbus_dev_frontend.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/xen/xenbus/xenbus_dev_frontend.c +++ b/drivers/xen/xenbus/xenbus_dev_frontend.c @@ -128,7 +128,7 @@ static ssize_t xenbus_file_read(struct f { struct xenbus_file_priv *u = filp->private_data; struct read_buffer *rb; - unsigned i; + ssize_t i; int ret; mutex_lock(&u->reply_mutex); @@ -148,7 +148,7 @@ again: rb = list_entry(u->read_buffers.next, struct read_buffer, list); i = 0; while (i < len) { - unsigned sz = min((unsigned)len - i, rb->len - rb->cons); + size_t sz = min_t(size_t, len - i, rb->len - rb->cons); ret = copy_to_user(ubuf + i, &rb->msg[rb->cons], sz);