From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9CC601FB9 for ; Fri, 3 Feb 2023 10:26:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E0556C433EF; Fri, 3 Feb 2023 10:26:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675419985; bh=b5vaDE5fSz5IIWOhUHG6/8wG3GSzRFW1zFBMUItJzLE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Xg5FeGmKJxFj+mF+C37h2XzQqbRX8wwsxmIYfv9/oelm7wXppU5ocGScSX9f4vtNG QOFap3xRts03Aj17VfNplleb38dicYRxzMd1jrMIU7l+vyT+eRbcLFRAfUQ8P/lqoJ 6JhZYR/VgZkJ+IWTjwqlScA5otoeIlsm1rP5sLrs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Szymon Heidrich , Alexander Duyck , Kalle Valo , Sasha Levin Subject: [PATCH 5.4 025/134] wifi: rndis_wlan: Prevent buffer overflow in rndis_query_oid Date: Fri, 3 Feb 2023 11:12:10 +0100 Message-Id: <20230203101024.979902962@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230203101023.832083974@linuxfoundation.org> References: <20230203101023.832083974@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Szymon Heidrich [ Upstream commit b870e73a56c4cccbec33224233eaf295839f228c ] Since resplen and respoffs are signed integers sufficiently large values of unsigned int len and offset members of RNDIS response will result in negative values of prior variables. This may be utilized to bypass implemented security checks to either extract memory contents by manipulating offset or overflow the data buffer via memcpy by manipulating both offset and len. Additionally assure that sum of resplen and respoffs does not overflow so buffer boundaries are kept. Fixes: 80f8c5b434f9 ("rndis_wlan: copy only useful data from rndis_command respond") Signed-off-by: Szymon Heidrich Reviewed-by: Alexander Duyck Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20230111175031.7049-1-szymon.heidrich@gmail.com Signed-off-by: Sasha Levin --- drivers/net/wireless/rndis_wlan.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) diff --git a/drivers/net/wireless/rndis_wlan.c b/drivers/net/wireless/rndis_wlan.c index c8f8fe5497a8..ace016967ff0 100644 --- a/drivers/net/wireless/rndis_wlan.c +++ b/drivers/net/wireless/rndis_wlan.c @@ -700,8 +700,8 @@ static int rndis_query_oid(struct usbnet *dev, u32 oid, void *data, int *len) struct rndis_query *get; struct rndis_query_c *get_c; } u; - int ret, buflen; - int resplen, respoffs, copylen; + int ret; + size_t buflen, resplen, respoffs, copylen; buflen = *len + sizeof(*u.get); if (buflen < CONTROL_BUFFER_SIZE) @@ -736,22 +736,15 @@ static int rndis_query_oid(struct usbnet *dev, u32 oid, void *data, int *len) if (respoffs > buflen) { /* Device returned data offset outside buffer, error. */ - netdev_dbg(dev->net, "%s(%s): received invalid " - "data offset: %d > %d\n", __func__, - oid_to_string(oid), respoffs, buflen); + netdev_dbg(dev->net, + "%s(%s): received invalid data offset: %zu > %zu\n", + __func__, oid_to_string(oid), respoffs, buflen); ret = -EINVAL; goto exit_unlock; } - if ((resplen + respoffs) > buflen) { - /* Device would have returned more data if buffer would - * have been big enough. Copy just the bits that we got. - */ - copylen = buflen - respoffs; - } else { - copylen = resplen; - } + copylen = min(resplen, buflen - respoffs); if (copylen > *len) copylen = *len; -- 2.39.0