sh_eth: fix NULL pointer dereference in sh_eth_ring_format()
In a low memory situation, if netdev_alloc_skb() fails on a first RX ring
loop iteration in sh_eth_ring_format(), 'rxdesc' is still NULL. Avoid
kernel oops by adding the 'rxdesc' check after the loop.
Reported-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index 9c64489..6fb75a1 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -1154,7 +1154,8 @@
mdp->dirty_rx = (u32) (i - mdp->num_rx_ring);
/* Mark the last entry as wrapping the ring. */
- rxdesc->status |= cpu_to_le32(RD_RDLE);
+ if (rxdesc)
+ rxdesc->status |= cpu_to_le32(RD_RDLE);
memset(mdp->tx_ring, 0, tx_ringsize);