4.20-stable review patch. If anyone has any objections, please let me know.
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From: Dan Carpenter dan.carpenter@oracle.com
[ Upstream commit 294c149a209c6196c2de85f512b52ef50f519949 ]
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@oracle.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/marvell/skge.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- 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_dev 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 */