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: c3f8be961808 ("[PATCH] skge: expand ethtool debug register dump")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
drivers/net/ethernet/marvell/skge.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/marvell/skge.c b/drivers/net/ethernet/marvell/skge.c
index 04fd1f135011..654ac534b10e 100644
--- a/drivers/net/ethernet/marvell/skge.c
+++ b/drivers/net/ethernet/marvell/skge.c
@@ -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 */
--
2.17.1
