skge: potential memory corruption in skge_get_regs()

The "p" buffer is 0x4000 bytes long.  B3_RI_WTO_R1 is 0x190.  The value
of "regs->len" is in the 1-0x4000 range.  The bug here is that
"regs->len - B3_RI_WTO_R1" can be a negative value which would lead to
memory corruption and an abrupt crash.

Fixes: c3f8be9618 ("[PATCH] skge: expand ethtool debug register dump")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Dan Carpenter 2019-02-01 11:28:16 +03:00 committed by David S. Miller
parent 5e66e35aab
commit 294c149a20

View File

@ -152,8 +152,10 @@ static void skge_get_regs(struct net_device *dev, struct ethtool_regs *regs,
memset(p, 0, regs->len);
memcpy_fromio(p, io, B3_RAM_ADDR);
memcpy_fromio(p + B3_RI_WTO_R1, io + B3_RI_WTO_R1,
regs->len - B3_RI_WTO_R1);
if (regs->len > B3_RI_WTO_R1) {
memcpy_fromio(p + B3_RI_WTO_R1, io + B3_RI_WTO_R1,
regs->len - B3_RI_WTO_R1);
}
}
/* Wake on Lan only supported on Yukon chips with rev 1 or above */