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Message-Id: <20220418121136.103360922@linuxfoundation.org>
Date: Mon, 18 Apr 2022 14:13:27 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Marcin Kozlowski <marcinguy@...il.com>,
"David S. Miller" <davem@...emloft.net>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.4 30/63] net: usb: aqc111: Fix out-of-bounds accesses in RX fixup
From: Marcin Kozlowski <marcinguy@...il.com>
[ Upstream commit afb8e246527536848b9b4025b40e613edf776a9d ]
aqc111_rx_fixup() contains several out-of-bounds accesses that can be
triggered by a malicious (or defective) USB device, in particular:
- The metadata array (desc_offset..desc_offset+2*pkt_count) 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.
Found doing variant analysis. Tested it with another driver (ax88179_178a), since
I don't have a aqc111 device to test it, but the code looks very similar.
Signed-off-by: Marcin Kozlowski <marcinguy@...il.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
drivers/net/usb/aqc111.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/net/usb/aqc111.c b/drivers/net/usb/aqc111.c
index 7e44110746dd..68912e266826 100644
--- a/drivers/net/usb/aqc111.c
+++ b/drivers/net/usb/aqc111.c
@@ -1102,10 +1102,15 @@ static int aqc111_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
if (start_of_descs != desc_offset)
goto err;
- /* self check desc_offset from header*/
- if (desc_offset >= skb_len)
+ /* self check desc_offset from header and make sure that the
+ * bounds of the metadata array are inside the SKB
+ */
+ if (pkt_count * 2 + desc_offset >= skb_len)
goto err;
+ /* Packets must not overlap the metadata array */
+ skb_trim(skb, desc_offset);
+
if (pkt_count == 0)
goto err;
--
2.35.1
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