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 C331DC433F5 for ; Sun, 13 Feb 2022 11:17:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235262AbiBMLRW (ORCPT ); Sun, 13 Feb 2022 06:17:22 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:38950 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229597AbiBMLRV (ORCPT ); Sun, 13 Feb 2022 06:17:21 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0997E656F for ; Sun, 13 Feb 2022 03:17:13 -0800 (PST) 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 8204361031 for ; Sun, 13 Feb 2022 11:17:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4BB28C004E1; Sun, 13 Feb 2022 11:17:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1644751032; bh=lROMolnrYJCthKUL4Up6TBQjFOf1lsZIyAOKw50C8RA=; h=Subject:To:Cc:From:Date:From; b=GZBNYUo9U8YuaS1FdWkHN2OZfsXMcWWN+867P97DxIxZPhGRmLmlkWcsv5qmPsB42 60bjrf41dlnArELRW1hH5vLLNyLdBSmvcZP0m9K92NggGivDL5XAsV73e6Jls5U4h7 k4Z0epln74BoVUBijwMnpsZK74BrmzwjFLncsHCc= Subject: FAILED: patch "[PATCH] net: usb: ax88179_178a: Fix out-of-bounds accesses in RX" failed to apply to 4.19-stable tree To: jannh@google.com, gregkh@linuxfoundation.org Cc: From: Date: Sun, 13 Feb 2022 12:16:59 +0100 Message-ID: <164475101912954@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 57bc3d3ae8c14df3ceb4e17d26ddf9eeab304581 Mon Sep 17 00:00:00 2001 From: Jann Horn Date: Wed, 26 Jan 2022 14:14:52 +0100 Subject: [PATCH] net: usb: ax88179_178a: Fix out-of-bounds accesses in RX fixup ax88179_rx_fixup() contains several out-of-bounds accesses that can be triggered by a malicious (or defective) USB device, in particular: - The metadata array (hdr_off..hdr_off+2*pkt_cnt) can be out of bounds, causing OOB reads and (on big-endian systems) OOB endianness flips. - A packet can overlap the metadata array, causing a later OOB endianness flip to corrupt data used by a cloned SKB that has already been handed off into the network stack. - A packet SKB can be constructed whose tail is far beyond its end, causing out-of-bounds heap data to be considered part of the SKB's data. I have tested that this can be used by a malicious USB device to send a bogus ICMPv6 Echo Request and receive an ICMPv6 Echo Reply in response that contains random kernel heap data. It's probably also possible to get OOB writes from this on a little-endian system somehow - maybe by triggering skb_cow() via IP options processing -, but I haven't tested that. Fixes: e2ca90c276e1 ("ax88179_178a: ASIX AX88179_178A USB 3.0/2.0 to gigabit ethernet adapter driver") Cc: stable@kernel.org Signed-off-by: Jann Horn Signed-off-by: Greg Kroah-Hartman diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c index 1a627ba4b850..a31098981a65 100644 --- a/drivers/net/usb/ax88179_178a.c +++ b/drivers/net/usb/ax88179_178a.c @@ -1468,58 +1468,68 @@ static int ax88179_rx_fixup(struct usbnet *dev, struct sk_buff *skb) u16 hdr_off; u32 *pkt_hdr; - /* This check is no longer done by usbnet */ - if (skb->len < dev->net->hard_header_len) + /* At the end of the SKB, there's a header telling us how many packets + * are bundled into this buffer and where we can find an array of + * per-packet metadata (which contains elements encoded into u16). + */ + if (skb->len < 4) return 0; - skb_trim(skb, skb->len - 4); rx_hdr = get_unaligned_le32(skb_tail_pointer(skb)); - pkt_cnt = (u16)rx_hdr; hdr_off = (u16)(rx_hdr >> 16); + + if (pkt_cnt == 0) + return 0; + + /* Make sure that the bounds of the metadata array are inside the SKB + * (and in front of the counter at the end). + */ + if (pkt_cnt * 2 + hdr_off > skb->len) + return 0; pkt_hdr = (u32 *)(skb->data + hdr_off); - while (pkt_cnt--) { + /* Packets must not overlap the metadata array */ + skb_trim(skb, hdr_off); + + for (; ; pkt_cnt--, pkt_hdr++) { u16 pkt_len; le32_to_cpus(pkt_hdr); pkt_len = (*pkt_hdr >> 16) & 0x1fff; - /* Check CRC or runt packet */ - if ((*pkt_hdr & AX_RXHDR_CRC_ERR) || - (*pkt_hdr & AX_RXHDR_DROP_ERR)) { - skb_pull(skb, (pkt_len + 7) & 0xFFF8); - pkt_hdr++; - continue; - } - - if (pkt_cnt == 0) { - skb->len = pkt_len; - /* Skip IP alignment pseudo header */ - skb_pull(skb, 2); - skb_set_tail_pointer(skb, skb->len); - skb->truesize = pkt_len + sizeof(struct sk_buff); - ax88179_rx_checksum(skb, pkt_hdr); - return 1; - } + if (pkt_len > skb->len) + return 0; - ax_skb = skb_clone(skb, GFP_ATOMIC); - if (ax_skb) { + /* Check CRC or runt packet */ + if (((*pkt_hdr & (AX_RXHDR_CRC_ERR | AX_RXHDR_DROP_ERR)) == 0) && + pkt_len >= 2 + ETH_HLEN) { + bool last = (pkt_cnt == 0); + + if (last) { + ax_skb = skb; + } else { + ax_skb = skb_clone(skb, GFP_ATOMIC); + if (!ax_skb) + return 0; + } ax_skb->len = pkt_len; /* Skip IP alignment pseudo header */ skb_pull(ax_skb, 2); skb_set_tail_pointer(ax_skb, ax_skb->len); ax_skb->truesize = pkt_len + sizeof(struct sk_buff); ax88179_rx_checksum(ax_skb, pkt_hdr); + + if (last) + return 1; + usbnet_skb_return(dev, ax_skb); - } else { - return 0; } - skb_pull(skb, (pkt_len + 7) & 0xFFF8); - pkt_hdr++; + /* Trim this packet away from the SKB */ + if (!skb_pull(skb, (pkt_len + 7) & 0xFFF8)) + return 0; } - return 1; } static struct sk_buff *