diff mbox

[1/2] sh_eth: fix NULL pointer dereference in sh_eth_ring_format()

Message ID 1725708.Wzdm5RnPU1@wasted.cogentembedded.com (mailing list archive)
State Accepted
Delegated to: Geert Uytterhoeven
Headers show

Commit Message

Sergei Shtylyov March 7, 2016, 10:36 p.m. UTC
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>

---
 drivers/net/ethernet/renesas/sh_eth.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox

Patch

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);