ip_sockglue: Fix missing-check bug in ip_ra_control()

In function ip_ra_control(), the pointer new_ra is allocated a memory
space via kmalloc(). And it is used in the following codes. However,
when  there is a memory allocation error, kmalloc() fails. Thus null
pointer dereference may happen. And it will cause the kernel to crash.
Therefore, we should check the return value and handle the error.

Signed-off-by: Gen Zhang <blackgod016574@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 82f341e84faecf3d273ea87785ca98d42f648f67..aa3fd61818c478602f0e72d20dd7a688f8900d83 100644 (file)
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -343,6 +343,8 @@ int ip_ra_control(struct sock *sk, unsigned char on,
                return -EINVAL;
 
        new_ra = on ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
+       if (on && !new_ra)
+               return -ENOMEM;
 
        mutex_lock(&net->ipv4.ra_mutex);
        for (rap = &net->ipv4.ra_chain;