2019-05-24 03:26:36

by Gen Zhang

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 <[email protected]>

---
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;

2019-05-25 18:03:04

by David Miller

Subject: Re: [PATCH] ip_sockglue: Fix missing-check bug in ip_ra_control()

From: Gen Zhang <[email protected]>
Date: Fri, 24 May 2019 11:24:26 +0800

> 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 <[email protected]>

Applied.