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 CCA1BCDB474 for ; Mon, 16 Oct 2023 08:46:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232649AbjJPIq6 (ORCPT ); Mon, 16 Oct 2023 04:46:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41040 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232785AbjJPIqy (ORCPT ); Mon, 16 Oct 2023 04:46:54 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D00AF3 for ; Mon, 16 Oct 2023 01:46:51 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3CAFC433C9; Mon, 16 Oct 2023 08:46:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1697446011; bh=5w/WJjqmn4tDsS8Oj+yA0EKD0lnAgac0w3fX83zjgDE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xmxcKMHwpkj6KBEFqTluPB6kGIYkwYQwxCc2Atd3a4SEQKYAikC7nmHHjEEyZ6h+3 qJU0Fi9onSSLfAuXWAnZRPf+EXsHYg7dRnGHLvJ5lZD1cBrLl3MsQsWHrB41yNIXqf WRUC40TulbB+vRpck9BpK/dokaXJ5jUGS9N5tfV4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Javier Carrasco , Peter Korsgaard , Jakub Kicinski , syzbot+1f53a30781af65d2c955@syzkaller.appspotmail.com Subject: [PATCH 5.15 050/102] net: usb: dm9601: fix uninitialized variable use in dm9601_mdio_read Date: Mon, 16 Oct 2023 10:40:49 +0200 Message-ID: <20231016083955.032954130@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231016083953.689300946@linuxfoundation.org> References: <20231016083953.689300946@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Javier Carrasco commit 8f8abb863fa5a4cc18955c6a0e17af0ded3e4a76 upstream. syzbot has found an uninit-value bug triggered by the dm9601 driver [1]. This error happens because the variable res is not updated if the call to dm_read_shared_word returns an error. In this particular case -EPROTO was returned and res stayed uninitialized. This can be avoided by checking the return value of dm_read_shared_word and propagating the error if the read operation failed. [1] https://syzkaller.appspot.com/bug?extid=1f53a30781af65d2c955 Cc: stable@vger.kernel.org Signed-off-by: Javier Carrasco Reported-and-tested-by: syzbot+1f53a30781af65d2c955@syzkaller.appspotmail.com Acked-by: Peter Korsgaard Fixes: d0374f4f9c35cdfbee0 ("USB: Davicom DM9601 usbnet driver") Link: https://lore.kernel.org/r/20231009-topic-dm9601_uninit_mdio_read-v2-1-f2fe39739b6c@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/net/usb/dm9601.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/drivers/net/usb/dm9601.c +++ b/drivers/net/usb/dm9601.c @@ -221,13 +221,18 @@ static int dm9601_mdio_read(struct net_d struct usbnet *dev = netdev_priv(netdev); __le16 res; + int err; if (phy_id) { netdev_dbg(dev->net, "Only internal phy supported\n"); return 0; } - dm_read_shared_word(dev, 1, loc, &res); + err = dm_read_shared_word(dev, 1, loc, &res); + if (err < 0) { + netdev_err(dev->net, "MDIO read error: %d\n", err); + return err; + } netdev_dbg(dev->net, "dm9601_mdio_read() phy_id=0x%02x, loc=0x%02x, returns=0x%04x\n",