linux-kernel - [PATCH 3.19.y-ckt 10/66] sh_eth: fix NULL pointer dereference in sh_eth_ring

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1461702297-7792-11-git-send-email-kamal@canonical.com>
Date:	Tue, 26 Apr 2016 13:24:01 -0700
From:	Kamal Mostafa <kamal@...onical.com>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com
Cc:	Sergei Shtylyov <sergei.shtylyov@...entembedded.com>,
	"David S . Miller" <davem@...emloft.net>,
	Kamal Mostafa <kamal@...onical.com>
Subject: [PATCH 3.19.y-ckt 10/66] sh_eth: fix NULL pointer dereference in sh_eth_ring_format()

3.19.8-ckt20 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Sergei Shtylyov <sergei.shtylyov@...entembedded.com>

[ 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@...g-engineering.com>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@...entembedded.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Kamal Mostafa <kamal@...onical.com>
---
 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 8fd0a6b..b03d858 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -1168,7 +1168,8 @@ 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);
 
-- 
2.7.4