caif: Bugfix - handle mem-allocation failures

Discovered bugs when injecting slab allocation failures.
Add checks on all memory allocation.

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 25 insertions, 9 deletions

diff --git a/net/caif/cfpkt_skbuff.c b/net/caif/cfpkt_skbuff.c
index 83fff2ff6658..a6fdf899741a 100644
--- a/net/caif/cfpkt_skbuff.c
+++ b/net/caif/cfpkt_skbuff.c
@@ -238,6 +238,7 @@ int cfpkt_add_head(struct cfpkt *pkt, const void *data2, u16 len)
         struct sk_buff *lastskb;
         u8 *to;
         const u8 *data = data2;
+        int ret;
         if (unlikely(is_erronous(pkt)))
                 return -EPROTO;
         if (unlikely(skb_headroom(skb) < len)) {
@@ -246,9 +247,10 @@ int cfpkt_add_head(struct cfpkt *pkt, const void *data2, u16 len)
         }
 
         /* Make sure data is writable */
-        if (unlikely(skb_cow_data(skb, 0, &lastskb) < 0)) {
+        ret = skb_cow_data(skb, 0, &lastskb);
+        if (unlikely(ret < 0)) {
                 PKT_ERROR(pkt, "cfpkt_add_head: cow failed\n");
-                return -EPROTO;
+                return ret;
         }
 
         to = skb_push(skb, len);
@@ -316,6 +318,8 @@ EXPORT_SYMBOL(cfpkt_setlen);
 struct cfpkt *cfpkt_create_uplink(const unsigned char *data, unsigned int len)
 {
         struct cfpkt *pkt = cfpkt_create_pfx(len + PKT_POSTFIX, PKT_PREFIX);
+        if (!pkt)
+                return NULL;
         if (unlikely(data != NULL))
                 cfpkt_add_body(pkt, data, len);
         return pkt;
@@ -344,12 +348,13 @@ struct cfpkt *cfpkt_append(struct cfpkt *dstpkt,
 
         if (dst->tail + neededtailspace > dst->end) {
                 /* Create a dumplicate of 'dst' with more tail space */
+                struct cfpkt *tmppkt;
                 dstlen = skb_headlen(dst);
                 createlen = dstlen + neededtailspace;
-                tmp = pkt_to_skb(
-                        cfpkt_create(createlen + PKT_PREFIX + PKT_POSTFIX));
-                if (!tmp)
+                tmppkt = cfpkt_create(createlen + PKT_PREFIX + PKT_POSTFIX);
+                if (tmppkt == NULL)
                         return NULL;
+                tmp = pkt_to_skb(tmppkt);
                 skb_set_tail_pointer(tmp, dstlen);
                 tmp->len = dstlen;
                 memcpy(tmp->data, dst->data, dstlen);
@@ -368,6 +373,7 @@ struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos)
 {
         struct sk_buff *skb2;
         struct sk_buff *skb = pkt_to_skb(pkt);
+        struct cfpkt *tmppkt;
         u8 *split = skb->data + pos;
         u16 len2nd = skb_tail_pointer(skb) - split;
 
@@ -381,9 +387,12 @@ struct cfpkt *cfpkt_split(struct cfpkt *pkt, u16 pos)
         }
 
         /* Create a new packet for the second part of the data */
-        skb2 = pkt_to_skb(
-                cfpkt_create_pfx(len2nd + PKT_PREFIX + PKT_POSTFIX,
-                                 PKT_PREFIX));
+        tmppkt = cfpkt_create_pfx(len2nd + PKT_PREFIX + PKT_POSTFIX,
+                                  PKT_PREFIX);
+        if (tmppkt == NULL)
+                return NULL;
+        skb2 = pkt_to_skb(tmppkt);
+
 
         if (skb2 == NULL)
                 return NULL;
diff --git a/net/caif/cfserl.c b/net/caif/cfserl.c
index 06029ea2da2f..cb4325a3dc83 100644
--- a/net/caif/cfserl.c
+++ b/net/caif/cfserl.c
@@ -67,6 +67,8 @@ static int cfserl_receive(struct cflayer *l, struct cfpkt *newpkt)
                 layr->incomplete_frm =
                     cfpkt_append(layr->incomplete_frm, newpkt, expectlen);
                 pkt = layr->incomplete_frm;
+                if (pkt == NULL)
+                        return -ENOMEM;
         } else {
                 pkt = newpkt;
         }
@@ -154,7 +156,6 @@ static int cfserl_receive(struct cflayer *l, struct cfpkt *newpkt)
                         if (layr->usestx) {
                                 if (tail_pkt != NULL)
                                         pkt = cfpkt_append(pkt, tail_pkt, 0);
-
                                 /* Start search for next STX if frame failed */
                                 continue;
                         } else {
diff --git a/net/caif/cfsrvl.c b/net/caif/cfsrvl.c
index aff31f34528f..6e5b7079a684 100644
--- a/net/caif/cfsrvl.c
+++ b/net/caif/cfsrvl.c
@@ -123,6 +123,12 @@ static int cfservl_modemcmd(struct cflayer *layr, enum caif_modemcmd ctrl)
                         struct caif_payload_info *info;
                         u8 flow_off = SRVL_FLOW_OFF;
                         pkt = cfpkt_create(SRVL_CTRL_PKT_SIZE);
+                        if (!pkt) {
+                                pr_warning("CAIF: %s(): Out of memory\n",
+                                        __func__);
+                                return -ENOMEM;
+                        }
+
                         if (cfpkt_add_head(pkt, &flow_off, 1) < 0) {
                                 pr_err("CAIF: %s(): Packet is erroneous!\n",
                                         __func__);