[PPP]: handle kmalloc failures and convert to using kzalloc

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.

[akpm@osdl.org: fix error-path leak]
[akpm@osdl.org: cleanups]
[paulus@samba.org: don't add useless printk and cardmap_destroy calls]

Signed-off-by: Panagiotis Issaris <takis@issaris.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 19 insertions, 11 deletions

diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c
index 0ec6e9d57b94..c872f7c6cce3 100644
--- a/drivers/net/ppp_generic.c
+++ b/drivers/net/ppp_generic.c
@@ -192,7 +192,7 @@ struct cardmap {
         void *ptr[CARDMAP_WIDTH];
 };
 static void *cardmap_get(struct cardmap *map, unsigned int nr);
-static void cardmap_set(struct cardmap **map, unsigned int nr, void *ptr);
+static int cardmap_set(struct cardmap **map, unsigned int nr, void *ptr);
 static unsigned int cardmap_find_first_free(struct cardmap *map);
 static void cardmap_destroy(struct cardmap **map);
 
@@ -1995,10 +1995,9 @@ ppp_register_channel(struct ppp_channel *chan)
 {
         struct channel *pch;
 
-        pch = kmalloc(sizeof(struct channel), GFP_KERNEL);
+        pch = kzalloc(sizeof(struct channel), GFP_KERNEL);
         if (pch == 0)
                 return -ENOMEM;
-        memset(pch, 0, sizeof(struct channel));
         pch->ppp = NULL;
         pch->chan = chan;
         chan->ppp = pch;
@@ -2408,13 +2407,12 @@ ppp_create_interface(int unit, int *retp)
         int ret = -ENOMEM;
         int i;
 
-        ppp = kmalloc(sizeof(struct ppp), GFP_KERNEL);
+        ppp = kzalloc(sizeof(struct ppp), GFP_KERNEL);
         if (!ppp)
                 goto out;
         dev = alloc_netdev(0, "", ppp_setup);
         if (!dev)
                 goto out1;
-        memset(ppp, 0, sizeof(struct ppp));
 
         ppp->mru = PPP_MRU;
         init_ppp_file(&ppp->file, INTERFACE);
@@ -2454,11 +2452,16 @@ ppp_create_interface(int unit, int *retp)
         }
 
         atomic_inc(&ppp_unit_count);
-        cardmap_set(&all_ppp_units, unit, ppp);
+        ret = cardmap_set(&all_ppp_units, unit, ppp);
+        if (ret != 0)
+                goto out3;
+
         mutex_unlock(&all_ppp_mutex);
         *retp = 0;
         return ppp;
 
+out3:
+        atomic_dec(&ppp_unit_count);
 out2:
         mutex_unlock(&all_ppp_mutex);
         free_netdev(dev);
@@ -2695,7 +2698,7 @@ static void *cardmap_get(struct cardmap *map, unsigned int nr)
         return NULL;
 }
 
-static void cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
+static int cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
 {
         struct cardmap *p;
         int i;
@@ -2704,8 +2707,9 @@ static void cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
         if (p == NULL || (nr >> p->shift) >= CARDMAP_WIDTH) {
                 do {
                         /* need a new top level */
-                        struct cardmap *np = kmalloc(sizeof(*np), GFP_KERNEL);
-                        memset(np, 0, sizeof(*np));
+                        struct cardmap *np = kzalloc(sizeof(*np), GFP_KERNEL);
+                        if (!np)
+                                goto enomem;
                         np->ptr[0] = p;
                         if (p != NULL) {
                                 np->shift = p->shift + CARDMAP_ORDER;
@@ -2719,8 +2723,9 @@ static void cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
         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)
+                                goto enomem;
                         np->shift = p->shift - CARDMAP_ORDER;
                         np->parent = p;
                         p->ptr[i] = np;
@@ -2735,6 +2740,9 @@ static void cardmap_set(struct cardmap **pmap, unsigned int nr, void *ptr)
                 set_bit(i, &p->inuse);
         else
                 clear_bit(i, &p->inuse);
+        return 0;
+ enomem:
+        return -ENOMEM;
 }
 
 static unsigned int cardmap_find_first_free(struct cardmap *map)