ATM, Solos PCI ADSL2+: Don't deref NULL pointer if net_ratelimit() and alloc_skb() interact badly.

If alloc_skb() fails to allocate memory and returns NULL then we want to
return -ENOMEM from drivers/atm/solos-pci.c::popen() regardless of the
value of net_ratelimit(). The way the code is today, we may not return if
net_ratelimit() returns 0, then we'll proceed to pass a NULL pointer to
skb_put() which will blow up in our face.
This patch ensures that we always return -ENOMEM on alloc_skb() failure
and only let the dev_warn() be controlled by the value of net_ratelimit().

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/atm/solos-pci.c b/drivers/atm/solos-pci.c
index 73fb1c4f4cd4..25ef1a4556e6 100644
--- a/drivers/atm/solos-pci.c
+++ b/drivers/atm/solos-pci.c
@@ -866,8 +866,9 @@ static int popen(struct atm_vcc *vcc)
         }
 
         skb = alloc_skb(sizeof(*header), GFP_ATOMIC);
-        if (!skb && net_ratelimit()) {
-                dev_warn(&card->dev->dev, "Failed to allocate sk_buff in popen()\n");
+        if (!skb) {
+                if (net_ratelimit())
+                        dev_warn(&card->dev->dev, "Failed to allocate sk_buff in popen()\n");
                 return -ENOMEM;
         }
         header = (void *)skb_put(skb, sizeof(*header));