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@xxxxxxxxx> --- diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index 82f341e..aa3fd61 100644 --- 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;
