From: Oliver Neukum oneukum@suse.com
[ Upstream commit ccab434e674ca95d483788b1895a70c21b7f016a ]
If a device sends a packet that is inbetween 0 and sizeof(u64) the value passed to skb_trim() as length will wrap around ending up as some very large value.
The driver will then proceed to parse the header located at that position, which will either oops or process some random value.
The fix is to check against sizeof(u64) rather than 0, which the driver currently does. The issue exists since the introduction of the driver.
Signed-off-by: Oliver Neukum oneukum@suse.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/usb/aqc111.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/net/usb/aqc111.c b/drivers/net/usb/aqc111.c index a017e9de2119d..7b8afa589a53c 100644 --- a/drivers/net/usb/aqc111.c +++ b/drivers/net/usb/aqc111.c @@ -1079,17 +1079,17 @@ static int aqc111_rx_fixup(struct usbnet *dev, struct sk_buff *skb) u16 pkt_count = 0; u64 desc_hdr = 0; u16 vlan_tag = 0; - u32 skb_len = 0; + u32 skb_len;
if (!skb) goto err;
- if (skb->len == 0) + skb_len = skb->len; + if (skb_len < sizeof(desc_hdr)) goto err;
- skb_len = skb->len; /* RX Descriptor Header */ - skb_trim(skb, skb->len - sizeof(desc_hdr)); + skb_trim(skb, skb_len - sizeof(desc_hdr)); desc_hdr = le64_to_cpup((u64 *)skb_tail_pointer(skb));
/* Check these packets */