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* [PATCH] ip_sockglue: Fix missing-check bug in ip_ra_control()
@ 2019-05-24  3:24 Gen Zhang
  2019-05-25 18:01 ` David Miller
  0 siblings, 1 reply; 2+ messages in thread
From: Gen Zhang @ 2019-05-24  3:24 UTC (permalink / raw)
  To: davem, kuznet, yoshfuji, ast, daniel, kafai, songliubraving, yhs
  Cc: netdev, linux-kernel, bpf

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>

---
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;

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH] ip_sockglue: Fix missing-check bug in ip_ra_control()
  2019-05-24  3:24 [PATCH] ip_sockglue: Fix missing-check bug in ip_ra_control() Gen Zhang
@ 2019-05-25 18:01 ` David Miller
  0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2019-05-25 18:01 UTC (permalink / raw)
  To: blackgod016574
  Cc: kuznet, yoshfuji, ast, daniel, kafai, songliubraving, yhs,
	netdev, linux-kernel, bpf

From: Gen Zhang <blackgod016574@gmail.com>
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 <blackgod016574@gmail.com>

Applied.

^ permalink raw reply	[flat|nested] 2+ messages in thread

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2019-05-24  3:24 [PATCH] ip_sockglue: Fix missing-check bug in ip_ra_control() Gen Zhang
2019-05-25 18:01 ` David Miller

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