ipv6_sockglue: Fix a missing-check bug in ip6_ra_control()

In function ip6_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/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index 40f21fef25ff459b0d2ec17c5679e29bf435297f..0a3d035feb6167e39057ef889d92ce308ab7d3b8 100644 (file)
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -68,6 +68,8 @@ int ip6_ra_control(struct sock *sk, int sel)
                return -ENOPROTOOPT;
 
        new_ra = (sel >= 0) ? kmalloc(sizeof(*new_ra), GFP_KERNEL) : NULL;
+       if (sel >= 0 && !new_ra)
+               return -ENOMEM;
 
        write_lock_bh(&ip6_ra_lock);
        for (rap = &ip6_ra_chain; (ra = *rap) != NULL; rap = &ra->next) {