caif: Handle dev_queue_xmit errors.

Do proper handling of dev_queue_xmit errors in order to
avoid double free of skb and leaks in error conditions.
In cfctrl pending requests are removed when CAIF Link layer goes down.

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

6 files changed, 117 insertions, 46 deletions

diff --git a/net/caif/caif_dev.c b/net/caif/caif_dev.c
index 0e651cf577cf..366ca0fb7a29 100644
--- a/net/caif/caif_dev.c
+++ b/net/caif/caif_dev.c
@@ -118,6 +118,7 @@ static struct caif_device_entry *caif_get(struct net_device *dev)
 
 static int transmit(struct cflayer *layer, struct cfpkt *pkt)
 {
+        int err;
         struct caif_device_entry *caifd =
             container_of(layer, struct caif_device_entry, layer);
         struct sk_buff *skb;
@@ -125,9 +126,11 @@ static int transmit(struct cflayer *layer, struct cfpkt *pkt)
         skb = cfpkt_tonative(pkt);
         skb->dev = caifd->netdev;
 
-        dev_queue_xmit(skb);
+        err = dev_queue_xmit(skb);
+        if (err > 0)
+                err = -EIO;
 
-        return 0;
+        return err;
 }
 
 /*
diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c
index 653db759eb7e..7baae11a6126 100644
--- a/net/caif/caif_socket.c
+++ b/net/caif/caif_socket.c
@@ -604,7 +604,9 @@ static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock,
                 goto err;
         ret = transmit_skb(skb, cf_sk, noblock, timeo);
         if (ret < 0)
-                goto err;
+                /* skb is already freed */
+                return ret;
+
         return len;
 err:
         kfree_skb(skb);
@@ -933,9 +935,9 @@ static int caif_release(struct socket *sock)
          * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
          * this ensures no packets when sock is dead.
          */
-        spin_lock(&sk->sk_receive_queue.lock);
+        spin_lock_bh(&sk->sk_receive_queue.lock);
         sock_set_flag(sk, SOCK_DEAD);
-        spin_unlock(&sk->sk_receive_queue.lock);
+        spin_unlock_bh(&sk->sk_receive_queue.lock);
         sock->sk = NULL;
 
         dbfs_atomic_inc(&cnt.num_disconnect);
diff --git a/net/caif/cfcnfg.c b/net/caif/cfcnfg.c
index e857d8995ca3..423009918f79 100644
--- a/net/caif/cfcnfg.c
+++ b/net/caif/cfcnfg.c
@@ -126,7 +126,7 @@ void cfcnfg_remove(struct cfcnfg *cfg)
                 synchronize_rcu();
 
                 kfree(cfg->mux);
-                kfree(cfg->ctrl);
+                cfctrl_remove(cfg->ctrl);
                 kfree(cfg);
         }
 }
diff --git a/net/caif/cfctrl.c b/net/caif/cfctrl.c
index 397a2c099e2c..0c00a6015dda 100644
--- a/net/caif/cfctrl.c
+++ b/net/caif/cfctrl.c
@@ -17,7 +17,6 @@
 #define UTILITY_NAME_LENGTH 16
 #define CFPKT_CTRL_PKT_LEN 20
 
-
 #ifdef CAIF_NO_LOOP
 static int handle_loop(struct cfctrl *ctrl,
                               int cmd, struct cfpkt *pkt){
@@ -51,13 +50,29 @@ struct cflayer *cfctrl_create(void)
         this->serv.layer.receive = cfctrl_recv;
         sprintf(this->serv.layer.name, "ctrl");
         this->serv.layer.ctrlcmd = cfctrl_ctrlcmd;
+#ifndef CAIF_NO_LOOP
         spin_lock_init(&this->loop_linkid_lock);
+        this->loop_linkid = 1;
+#endif
         spin_lock_init(&this->info_list_lock);
         INIT_LIST_HEAD(&this->list);
-        this->loop_linkid = 1;
         return &this->serv.layer;
 }
 
+void cfctrl_remove(struct cflayer *layer)
+{
+        struct cfctrl_request_info *p, *tmp;
+        struct cfctrl *ctrl = container_obj(layer);
+
+        spin_lock_bh(&ctrl->info_list_lock);
+        list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
+                list_del(&p->list);
+                kfree(p);
+        }
+        spin_unlock_bh(&ctrl->info_list_lock);
+        kfree(layer);
+}
+
 static bool param_eq(const struct cfctrl_link_param *p1,
                         const struct cfctrl_link_param *p2)
 {
@@ -116,11 +131,11 @@ static bool cfctrl_req_eq(const struct cfctrl_request_info *r1,
 static void cfctrl_insert_req(struct cfctrl *ctrl,
                               struct cfctrl_request_info *req)
 {
-        spin_lock(&ctrl->info_list_lock);
+        spin_lock_bh(&ctrl->info_list_lock);
         atomic_inc(&ctrl->req_seq_no);
         req->sequence_no = atomic_read(&ctrl->req_seq_no);
         list_add_tail(&req->list, &ctrl->list);
-        spin_unlock(&ctrl->info_list_lock);
+        spin_unlock_bh(&ctrl->info_list_lock);
 }
 
 /* Compare and remove request */
@@ -129,7 +144,6 @@ static struct cfctrl_request_info *cfctrl_remove_req(struct cfctrl *ctrl,
 {
         struct cfctrl_request_info *p, *tmp, *first;
 
-        spin_lock(&ctrl->info_list_lock);
         first = list_first_entry(&ctrl->list, struct cfctrl_request_info, list);
 
         list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
@@ -145,7 +159,6 @@ static struct cfctrl_request_info *cfctrl_remove_req(struct cfctrl *ctrl,
         }
         p = NULL;
 out:
-        spin_unlock(&ctrl->info_list_lock);
         return p;
 }
 
@@ -179,10 +192,6 @@ void cfctrl_enum_req(struct cflayer *layer, u8 physlinkid)
         cfpkt_addbdy(pkt, physlinkid);
         ret =
             cfctrl->serv.layer.dn->transmit(cfctrl->serv.layer.dn, pkt);
-        if (ret < 0) {
-                pr_err("Could not transmit enum message\n");
-                cfpkt_destroy(pkt);
-        }
 }
 
 int cfctrl_linkup_request(struct cflayer *layer,
@@ -196,14 +205,23 @@ int cfctrl_linkup_request(struct cflayer *layer,
         struct cfctrl_request_info *req;
         int ret;
         char utility_name[16];
-        struct cfpkt *pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
+        struct cfpkt *pkt;
+
+        if (cfctrl_cancel_req(layer, user_layer) > 0) {
+                /* Slight Paranoia, check if already connecting */
+                pr_err("Duplicate connect request for same client\n");
+                WARN_ON(1);
+                return -EALREADY;
+        }
+
+        pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
         if (!pkt) {
                 pr_warn("Out of memory\n");
                 return -ENOMEM;
         }
         cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_SETUP);
-        cfpkt_addbdy(pkt, (param->chtype << 4) + param->linktype);
-        cfpkt_addbdy(pkt, (param->priority << 3) + param->phyid);
+        cfpkt_addbdy(pkt, (param->chtype << 4) | param->linktype);
+        cfpkt_addbdy(pkt, (param->priority << 3) | param->phyid);
         cfpkt_addbdy(pkt, param->endpoint & 0x03);
 
         switch (param->linktype) {
@@ -266,9 +284,13 @@ int cfctrl_linkup_request(struct cflayer *layer,
         ret =
             cfctrl->serv.layer.dn->transmit(cfctrl->serv.layer.dn, pkt);
         if (ret < 0) {
-                pr_err("Could not transmit linksetup request\n");
-                cfpkt_destroy(pkt);
-                return -ENODEV;
+                int count;
+
+                count = cfctrl_cancel_req(&cfctrl->serv.layer,
+                                                user_layer);
+                if (count != 1)
+                        pr_err("Could not remove request (%d)", count);
+                        return -ENODEV;
         }
         return 0;
 }
@@ -288,28 +310,29 @@ int cfctrl_linkdown_req(struct cflayer *layer, u8 channelid,
         init_info(cfpkt_info(pkt), cfctrl);
         ret =
             cfctrl->serv.layer.dn->transmit(cfctrl->serv.layer.dn, pkt);
-        if (ret < 0) {
-                pr_err("Could not transmit link-down request\n");
-                cfpkt_destroy(pkt);
-        }
+#ifndef CAIF_NO_LOOP
+        cfctrl->loop_linkused[channelid] = 0;
+#endif
         return ret;
 }
 
-void cfctrl_cancel_req(struct cflayer *layr, struct cflayer *adap_layer)
+int cfctrl_cancel_req(struct cflayer *layr, struct cflayer *adap_layer)
 {
         struct cfctrl_request_info *p, *tmp;
         struct cfctrl *ctrl = container_obj(layr);
-        spin_lock(&ctrl->info_list_lock);
+        int found = 0;
+        spin_lock_bh(&ctrl->info_list_lock);
 
         list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
                 if (p->client_layer == adap_layer) {
-                        pr_debug("cancel req :%d\n", p->sequence_no);
                         list_del(&p->list);
                         kfree(p);
+                        found++;
                 }
         }
 
-        spin_unlock(&ctrl->info_list_lock);
+        spin_unlock_bh(&ctrl->info_list_lock);
+        return found;
 }
 
 static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
@@ -461,6 +484,7 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
 
                         rsp.cmd = cmd;
                         rsp.param = linkparam;
+                        spin_lock_bh(&cfctrl->info_list_lock);
                         req = cfctrl_remove_req(cfctrl, &rsp);
 
                         if (CFCTRL_ERR_BIT == (CFCTRL_ERR_BIT & cmdrsp) ||
@@ -480,6 +504,8 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
 
                         if (req != NULL)
                                 kfree(req);
+
+                        spin_unlock_bh(&cfctrl->info_list_lock);
                 }
                 break;
         case CFCTRL_CMD_LINK_DESTROY:
@@ -523,12 +549,29 @@ static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
         switch (ctrl) {
         case _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND:
         case CAIF_CTRLCMD_FLOW_OFF_IND:
-                spin_lock(&this->info_list_lock);
+                spin_lock_bh(&this->info_list_lock);
                 if (!list_empty(&this->list)) {
                         pr_debug("Received flow off in control layer\n");
                 }
-                spin_unlock(&this->info_list_lock);
+                spin_unlock_bh(&this->info_list_lock);
                 break;
+        case _CAIF_CTRLCMD_PHYIF_DOWN_IND: {
+                struct cfctrl_request_info *p, *tmp;
+
+                /* Find all connect request and report failure */
+                spin_lock_bh(&this->info_list_lock);
+                list_for_each_entry_safe(p, tmp, &this->list, list) {
+                        if (p->param.phyid == phyid) {
+                                list_del(&p->list);
+                                p->client_layer->ctrlcmd(p->client_layer,
+                                                CAIF_CTRLCMD_INIT_FAIL_RSP,
+                                                phyid);
+                                kfree(p);
+                        }
+                }
+                spin_unlock_bh(&this->info_list_lock);
+                break;
+        }
         default:
                 break;
         }
@@ -538,27 +581,33 @@ static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
 static int handle_loop(struct cfctrl *ctrl, int cmd, struct cfpkt *pkt)
 {
         static int last_linkid;
+        static int dec;
         u8 linkid, linktype, tmp;
         switch (cmd) {
         case CFCTRL_CMD_LINK_SETUP:
-                spin_lock(&ctrl->loop_linkid_lock);
-                for (linkid = last_linkid + 1; linkid < 255; linkid++)
-                        if (!ctrl->loop_linkused[linkid])
-                                goto found;
+                spin_lock_bh(&ctrl->loop_linkid_lock);
+                if (!dec) {
+                        for (linkid = last_linkid + 1; linkid < 255; linkid++)
+                                if (!ctrl->loop_linkused[linkid])
+                                        goto found;
+                }
+                dec = 1;
                 for (linkid = last_linkid - 1; linkid > 0; linkid--)
                         if (!ctrl->loop_linkused[linkid])
                                 goto found;
-                spin_unlock(&ctrl->loop_linkid_lock);
-                pr_err("Out of link-ids\n");
-                return -EINVAL;
+                spin_unlock_bh(&ctrl->loop_linkid_lock);
+
 found:
+                if (linkid < 10)
+                        dec = 0;
+
                 if (!ctrl->loop_linkused[linkid])
                         ctrl->loop_linkused[linkid] = 1;
 
                 last_linkid = linkid;
 
                 cfpkt_add_trail(pkt, &linkid, 1);
-                spin_unlock(&ctrl->loop_linkid_lock);
+                spin_unlock_bh(&ctrl->loop_linkid_lock);
                 cfpkt_peek_head(pkt, &linktype, 1);
                 if (linktype ==  CFCTRL_SRV_UTIL) {
                         tmp = 0x01;
@@ -568,10 +617,10 @@ found:
                 break;
 
         case CFCTRL_CMD_LINK_DESTROY:
-                spin_lock(&ctrl->loop_linkid_lock);
+                spin_lock_bh(&ctrl->loop_linkid_lock);
                 cfpkt_peek_head(pkt, &linkid, 1);
                 ctrl->loop_linkused[linkid] = 0;
-                spin_unlock(&ctrl->loop_linkid_lock);
+                spin_unlock_bh(&ctrl->loop_linkid_lock);
                 break;
         default:
                 break;
diff --git a/net/caif/cffrml.c b/net/caif/cffrml.c
index 4f4f756c49ac..04204b202718 100644
--- a/net/caif/cffrml.c
+++ b/net/caif/cffrml.c
@@ -33,7 +33,6 @@ static void cffrml_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
 static u32 cffrml_rcv_error;
 static u32 cffrml_rcv_checsum_error;
 struct cflayer *cffrml_create(u16 phyid, bool use_fcs)
-
 {
         struct cffrml *this = kmalloc(sizeof(struct cffrml), GFP_ATOMIC);
         if (!this) {
@@ -128,6 +127,13 @@ static int cffrml_receive(struct cflayer *layr, struct cfpkt *pkt)
                 cfpkt_destroy(pkt);
                 return -EPROTO;
         }
+
+        if (layr->up == NULL) {
+                pr_err("Layr up is missing!\n");
+                cfpkt_destroy(pkt);
+                return -EINVAL;
+        }
+
         return layr->up->receive(layr->up, pkt);
 }
 
@@ -150,15 +156,22 @@ static int cffrml_transmit(struct cflayer *layr, struct cfpkt *pkt)
         cfpkt_info(pkt)->hdr_len += 2;
         if (cfpkt_erroneous(pkt)) {
                 pr_err("Packet is erroneous!\n");
+                cfpkt_destroy(pkt);
                 return -EPROTO;
         }
+
+        if (layr->dn == NULL) {
+                cfpkt_destroy(pkt);
+                return -ENODEV;
+
+        }
         return layr->dn->transmit(layr->dn, pkt);
 }
 
 static void cffrml_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
                                         int phyid)
 {
-        if (layr->up->ctrlcmd)
+        if (layr->up && layr->up->ctrlcmd)
                 layr->up->ctrlcmd(layr->up, ctrl, layr->id);
 }
 
diff --git a/net/caif/cfveil.c b/net/caif/cfveil.c
index 1a588cd818ea..3ec83fbc2887 100644
--- a/net/caif/cfveil.c
+++ b/net/caif/cfveil.c
@@ -82,13 +82,14 @@ static int cfvei_transmit(struct cflayer *layr, struct cfpkt *pkt)
         int ret;
         struct cfsrvl *service = container_obj(layr);
         if (!cfsrvl_ready(service, &ret))
-                return ret;
+                goto err;
         caif_assert(layr->dn != NULL);
         caif_assert(layr->dn->transmit != NULL);
 
         if (cfpkt_add_head(pkt, &tmp, 1) < 0) {
                 pr_err("Packet is erroneous!\n");
-                return -EPROTO;
+                ret = -EPROTO;
+                goto err;
         }
 
         /* Add info-> for MUX-layer to route the packet out. */
@@ -97,4 +98,7 @@ static int cfvei_transmit(struct cflayer *layr, struct cfpkt *pkt)
         info->hdr_len = 1;
         info->dev_info = &service->dev_info;
         return layr->dn->transmit(layr->dn, pkt);
+err:
+        cfpkt_destroy(pkt);
+        return ret;
 }