[added to the 4.1 stable tree] sh_eth: fix NULL pointer dereference in sh_eth_ring_format()
From: Sasha Levin <hidden>
Date: 2016-07-12 02:58:21
Subsystem:
networking drivers, renesas superh ethernet driver, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Niklas Söderlund, Linus Torvalds
From: Sergei Shtylyov <redacted> This patch has been added to the 4.1 stable tree. If you have any objections, please let us know. =============== [ Upstream commit c1b7fca65070bfadca94dd53a4e6b71cd4f69715 ] 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 <redacted> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <redacted> --- drivers/net/ethernet/renesas/sh_eth.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index 13463c4..51eff9f 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c@@ -1173,7 +1173,8 @@ static void sh_eth_ring_format(struct net_device *ndev) mdp->dirty_rx = (u32) (i - mdp->num_rx_ring); /* Mark the last entry as wrapping the ring. */ - rxdesc->status |= cpu_to_edmac(mdp, RD_RDEL); + if (rxdesc) + rxdesc->status |= cpu_to_edmac(mdp, RD_RDEL); memset(mdp->tx_ring, 0, tx_ringsize);
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2.5.0