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@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/renesas/sh_eth.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) Index: net/drivers/net/ethernet/renesas/sh_eth.c =================================================================== --- net.orig/drivers/net/ethernet/renesas/sh_eth.c +++ net/drivers/net/ethernet/renesas/sh_eth.c @@ -1163,7 +1163,8 @@ static void sh_eth_ring_format(struct ne 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);
