[PATCH] netdevice: Fix wrong string handle in kernel command line parsing

[PATCH] netdevice: Fix wrong string handle in kernel command line parsing

[Wang Chen]

1. In netdev_boot_setup_add(), a long name will leak.
   ex. : dev=21,0x1234,0x1234,0x2345,eth123456789verylongname.........
2. In netdev_boot_setup_check(), mismatch will happen if s[i].name
   is a substring of dev->name.
   ex. : dev=...eth1 dev=...eth11

Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
---
diff --git a/net/core/dev.c b/net/core/dev.c
index c421a1f..9ecb3db 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -454,7 +454,7 @@ static int netdev_boot_setup_add(char *name, struct ifmap *map)
 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
 		if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
 			memset(s[i].name, 0, sizeof(s[i].name));
-			strcpy(s[i].name, name);
+			strncpy(s[i].name, name, IFNAMSIZ);
 			memcpy(&s[i].map, map, sizeof(s[i].map));
 			break;
 		}
@@ -479,7 +479,7 @@ int netdev_boot_setup_check(struct net_device *dev)
 
 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
 		if (s[i].name[0] != '\0' && s[i].name[0] != ' ' &&
-		    !strncmp(dev->name, s[i].name, strlen(s[i].name))) {
+		    !strcmp(dev->name, s[i].name)) {
 			dev->irq 	= s[i].map.irq;
 			dev->base_addr 	= s[i].map.base_addr;
 			dev->mem_start 	= s[i].map.mem_start;

Re: [PATCH] netdevice: Fix wrong string handle in kernel command line parsing

[Ben Hutchings]

Wang Chen wrote:
> 1. In netdev_boot_setup_add(), a long name will leak.
>    ex. : dev=21,0x1234,0x1234,0x2345,eth123456789verylongname.........
> 2. In netdev_boot_setup_check(), mismatch will happen if s[i].name
>    is a substring of dev->name.
>    ex. : dev=...eth1 dev=...eth11

Well spotted, but...

> Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
> ---
> diff --git a/net/core/dev.c b/net/core/dev.c
> index c421a1f..9ecb3db 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -454,7 +454,7 @@ static int netdev_boot_setup_add(char *name, struct ifmap *map)
>  	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
>  		if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
>  			memset(s[i].name, 0, sizeof(s[i].name));
> -			strcpy(s[i].name, name);
> +			strncpy(s[i].name, name, IFNAMSIZ);

I think that strncpy() should be strlcpy(), because strncpy() does not
ensure null-termination.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.

V2 [PATCH] netdevice: Fix wrong string handle in kernel command line parsing

[Wang Chen]

Ben Hutchings said the following on 2008-6-30 18:25:
>> -			strcpy(s[i].name, name);
>> +			strncpy(s[i].name, name, IFNAMSIZ);
> 
> I think that strncpy() should be strlcpy(), because strncpy() does not
> ensure null-termination.
> 

Of course. Thanks, Ben.

v1->v2: Use strlcpy() to ensure s[i].name be null-termination.

1. In netdev_boot_setup_add(), a long name will leak.
   ex. : dev=21,0x1234,0x1234,0x2345,eth123456789verylongname.........
2. In netdev_boot_setup_check(), mismatch will happen if s[i].name
   is a substring of dev->name.
   ex. : dev=...eth1 dev=...eth11

Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
---
diff --git a/net/core/dev.c b/net/core/dev.c
index c421a1f..3360df6 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -454,7 +454,7 @@ static int netdev_boot_setup_add(char *name, struct ifmap *map)
 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
 		if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
 			memset(s[i].name, 0, sizeof(s[i].name));
-			strcpy(s[i].name, name);
+			strlcpy(s[i].name, name, IFNAMSIZ);
 			memcpy(&s[i].map, map, sizeof(s[i].map));
 			break;
 		}
@@ -479,7 +479,7 @@ int netdev_boot_setup_check(struct net_device *dev)
 
 	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
 		if (s[i].name[0] != '\0' && s[i].name[0] != ' ' &&
-		    !strncmp(dev->name, s[i].name, strlen(s[i].name))) {
+		    !strcmp(dev->name, s[i].name)) {
 			dev->irq 	= s[i].map.irq;
 			dev->base_addr 	= s[i].map.base_addr;
 			dev->mem_start 	= s[i].map.mem_start;

Re: V2 [PATCH] netdevice: Fix wrong string handle in kernel command line parsing

[David Miller]

From: Wang Chen <wangchen@cn.fujitsu.com>
Date: Tue, 01 Jul 2008 08:56:40 +0800

> Ben Hutchings said the following on 2008-6-30 18:25:
> >> -			strcpy(s[i].name, name);
> >> +			strncpy(s[i].name, name, IFNAMSIZ);
> > 
> > I think that strncpy() should be strlcpy(), because strncpy() does not
> > ensure null-termination.
> > 
> 
> Of course. Thanks, Ben.
> 
> v1->v2: Use strlcpy() to ensure s[i].name be null-termination.
> 
> 1. In netdev_boot_setup_add(), a long name will leak.
>    ex. : dev=21,0x1234,0x1234,0x2345,eth123456789verylongname.........
> 2. In netdev_boot_setup_check(), mismatch will happen if s[i].name
>    is a substring of dev->name.
>    ex. : dev=...eth1 dev=...eth11
> 
> Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>

Looks good, applied, thanks everyone.