2008-02-15 09:46:23

by Keiichi KII

Subject: [PATCH] netconsole: avoid null pointer dereference at show_local_mac()

From: Keiichi KII <[email protected]>

This patch avoids a null pointer dereference when we read local_mac
for netconsole in configfs and shows default local mac address
value.

A null pointer dereference occurs when we call show_local_mac() via
local_mac entry in configfs before we setup the content of netpoll
using netpoll_setup().

This patch is for 2.6.25-rc1.
Your comments are very welcome.

Signed-off-by: Keiichi KII <[email protected]>
---
Index: pre-release/drivers/net/netconsole.c
===================================================================
--- pre-release.orig/drivers/net/netconsole.c
+++ pre-release/drivers/net/netconsole.c
@@ -309,8 +309,8 @@ static ssize_t show_local_mac(struct net
struct net_device *dev = nt->np.dev;

DECLARE_MAC_BUF(mac);
- return snprintf(buf, PAGE_SIZE, "%s\n",
- print_mac(mac, dev->dev_addr));
+ return snprintf(buf, PAGE_SIZE, "%s\n", dev ?
+ print_mac(mac, dev->dev_addr) : "ff:ff:ff:ff:ff:ff");
}

static ssize_t show_remote_mac(struct netconsole_target *nt, char *buf)

--
Keiichi KII
NEC Corporation OSS Platform Development Division
E-mail: [email protected]

2008-02-15 10:01:52

by David Miller

Subject: Re: [PATCH] netconsole: avoid null pointer dereference at show_local_mac()

From: Keiichi KII <[email protected]>
Date: Fri, 15 Feb 2008 18:45:48 +0900

> This patch avoids a null pointer dereference when we read local_mac
> for netconsole in configfs and shows default local mac address
> value.
>
> A null pointer dereference occurs when we call show_local_mac() via
> local_mac entry in configfs before we setup the content of netpoll
> using netpoll_setup().
>
> This patch is for 2.6.25-rc1.
> Your comments are very welcome.
>
> Signed-off-by: Keiichi KII <[email protected]>

Patch applied, thank you.