Subject: Re: [PATCH 2.6.19-rc2] [REVISED] net/ipv4/multipath_wrandom.c: check kmalloc() return value.

From: Patrick McHardy <[email-masked]>
Date: Mon, 23 Oct 2006 13:17:54 +0200

Amit Choudhary wrote:
> Description: Check the return value of kmalloc() in function wrandom_set_nhinfo(), in file net/ipv4/multipath_wrandom.c.
> 
> Signed-off-by: Amit Choudhary <[email-masked]>
> 
> diff --git a/net/ipv4/multipath_wrandom.c b/net/ipv4/multipath_wrandom.c
> index 92b0482..bcdb1f1 100644
> --- a/net/ipv4/multipath_wrandom.c
> +++ b/net/ipv4/multipath_wrandom.c
> @@ -242,6 +242,9 @@ static void wrandom_set_nhinfo(__be32 ne
>  		target_route = (struct multipath_route *)
>  			kmalloc(size_rt, GFP_ATOMIC);
>  
> +		if (!target_route)
> +			goto error;
> +
>  		target_route->gw = nh->nh_gw;
>  		target_route->oif = nh->nh_oif;
>  		memset(&target_route->rcu, 0, sizeof(struct rcu_head));
> @@ -263,6 +266,9 @@ static void wrandom_set_nhinfo(__be32 ne
>  		target_dest = (struct multipath_dest*)
>  			kmalloc(size_dst, GFP_ATOMIC);
>  
> +		if (!target_dest)
> +			goto error;
> +
>
>  		target_dest->nh_info = nh;
>  		target_dest->network = network;
>  		target_dest->netmask = netmask;
> @@ -275,6 +281,7 @@ static void wrandom_set_nhinfo(__be32 ne
>  	 * we are finished
>  	 */
>  
> + error:
>  	spin_unlock_bh(&state[state_idx].lock);
>  }

Thats slightly better than before, but since no errors are propagated
back to the routing code I think it would still crash later on.
A better idea would be to mark this crap BROKEN until it is really
fixed, so people won't accidentally enable it (which is enough
to cause problems).

Signed-off-by: Patrick McHardy <[email-masked]>

diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 5572071..9ff5616 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -124,8 +124,8 @@ config IP_ROUTE_MULTIPATH
 	  if a matching packet arrives.
 
 config IP_ROUTE_MULTIPATH_CACHED
-	bool "IP: equal cost multipath with caching support (EXPERIMENTAL)"
-	depends on IP_ROUTE_MULTIPATH
+	bool "IP: equal cost multipath with caching support (BROKEN)"
+	depends on IP_ROUTE_MULTIPATH && BROKEN
 	help
 	  Normally, equal cost multipath routing is not supported by the
 	  routing cache. If you say Y here, alternative routes are cached