Blob Blame Raw
From 425aa0e1d01513437668fa3d4a971168bbaa8515 Mon Sep 17 00:00:00 2001
From: Gen Zhang <blackgod016574@gmail.com>
Date: Fri, 24 May 2019 11:24:26 +0800
Subject: [PATCH] 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>
---
 net/ipv4/ip_sockglue.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 82f341e84fae..aa3fd61818c4 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;
-- 
2.21.0