From: Gen Zhang <blackgod016574@xxxxxxxxx> commit 95baa60a0da80a0143e3ddd4d3725758b4513825 upstream. 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@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Srivatsa S. Bhat (VMware) <srivatsa@xxxxxxxxxxxxx> --- net/ipv6/ipv6_sockglue.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c index c0cac9c..4bc97b1 100644 --- 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) {