From: Marcin Kozlowski marcinguy@gmail.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@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.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 0717c18015c9..c9c409518174 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;