Re: [PATCH] Missing failure handling

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, 20 Jul 2006 21:16:29 +0200
takis@xxxxxxxxxxxxxxxxxxx (Panagiotis Issaris) wrote:

> From: Panagiotis Issaris <takis@xxxxxxxxxxx>
> 
> The PPP code contains two kmalloc()s followed by memset()s without
> handling a possible memory allocation failure. (Suggested by 
> Joe Perches).
> 
> And furthermore, conversions from kmalloc+memset to kzalloc.

OK...

> -			struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL);
> -			memset(np, 0, sizeof(*np));
> +			struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
> +			if (!np) {
> +				printk(KERN_ERR "PPP: no memory (cardmap)\n");
> +				return -ENOMEM;
> +			}
>  			np->ptr[0] = p;
>  			if (p != NULL) {
>  				np->shift = p->shift + CARDMAP_ORDER;
> @@ -2719,8 +2727,11 @@ static void cardmap_set(struct cardmap *
>  	while (p->shift > 0) {
>  		i = (nr >> p->shift) & CARDMAP_MASK;
>  		if (p->ptr[i] == NULL) {
> -			struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL);
> -			memset(np, 0, sizeof(*np));
> +			struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
> +			if (!np) {
> +				printk(KERN_ERR "PPP: no memory (cardmap)\n");
> +				return -ENOMEM;
> +			}
>  			np->shift = p->shift - CARDMAP_ORDER;

But this leaks memory on errors.

It looks like cardmap_destroy() will handle a partially-constructed map,
so..

--- a/drivers/net/ppp_generic.c~ppp-handle-kmalloc-failures-leak-fix
+++ a/drivers/net/ppp_generic.c
@@ -2710,10 +2710,8 @@ static int cardmap_set(struct cardmap **
 		do {
 			/* need a new top level */
 			struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
-			if (!np) {
-				printk(KERN_ERR "PPP: no memory (cardmap)\n");
-				return -ENOMEM;
-			}
+			if (!np)
+				goto enomem;
 			np->ptr[0] = p;
 			if (p != NULL) {
 				np->shift = p->shift + CARDMAP_ORDER;
@@ -2728,10 +2726,8 @@ static int cardmap_set(struct cardmap **
 		i = (nr >> p->shift) & CARDMAP_MASK;
 		if (p->ptr[i] == NULL) {
 			struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
-			if (!np) {
-				printk(KERN_ERR "PPP: no memory (cardmap)\n");
-				return -ENOMEM;
-			}
+			if (!np)
+				goto enomem;
 			np->shift = p->shift - CARDMAP_ORDER;
 			np->parent = p;
 			p->ptr[i] = np;
@@ -2747,6 +2743,10 @@ static int cardmap_set(struct cardmap **
 	else
 		clear_bit(i, &p->inuse);
 	return 0;
+enomem:
+	printk(KERN_ERR "PPP: no memory (cardmap)\n");
+	cardmap_destroy(pmap);
+	return -ENOMEM;
 }
 
 static unsigned int cardmap_find_first_free(struct cardmap *map)
_

-
To unsubscribe from this list: send the line "unsubscribe linux-ppp" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Audio Users]     [Linux for Hams]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Fedora Users]

  Powered by Linux