[PATCH 4.19 22/58] net: caif: add proper error handling

Greg Kroah-Hartman
2021-06-08T18:39:00Z

From: Pavel Skripkin <paskripkin@gmail.com>

commit a2805dca5107d5603f4bbc027e81e20d93476e96 upstream.

caif_enroll_dev() can fail in some cases. Ingnoring
these cases can lead to memory leak due to not assigning
link_support pointer to anywhere.

Fixes: 7c18d2205ea7 ("caif: Restructure how link caif link layer enroll")
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/net/caif/caif_dev.h | 2 +-
include/net/caif/cfcnfg.h | 2 +-
net/caif/caif_dev.c | 8 +++++---
net/caif/cfcnfg.c | 16 +++++++++++-----
4 files changed, 18 insertions(+), 10 deletions(-)

--- a/include/net/caif/caif_dev.h
+++ b/include/net/caif/caif_dev.h
@@ -119,7 +119,7 @@ void caif_free_client(struct cflayer *ad
* The link_support layer is used to add any Link Layer specific
* framing.
*/
-void caif_enroll_dev(struct net_device *dev, struct caif_dev_common *caifdev,
+int caif_enroll_dev(struct net_device *dev, struct caif_dev_common *caifdev,
struct cflayer *link_support, int head_room,
struct cflayer **layer, int (**rcv_func)(
struct sk_buff *, struct net_device *,
--- a/include/net/caif/cfcnfg.h
+++ b/include/net/caif/cfcnfg.h
@@ -62,7 +62,7 @@ void cfcnfg_remove(struct cfcnfg *cfg);
* @fcs: Specify if checksum is used in CAIF Framing Layer.
* @head_room: Head space needed by link specific protocol.
*/
-void
+int
cfcnfg_add_phy_layer(struct cfcnfg *cnfg,
struct net_device *dev, struct cflayer *phy_layer,
enum cfcnfg_phy_preference pref,
--- a/net/caif/caif_dev.c
+++ b/net/caif/caif_dev.c
@@ -303,7 +303,7 @@ static void dev_flowctrl(struct net_devi
caifd_put(caifd);
}

-void caif_enroll_dev(struct net_device *dev, struct caif_dev_common *caifdev,
+int caif_enroll_dev(struct net_device *dev, struct caif_dev_common *caifdev,
struct cflayer *link_support, int head_room,
struct cflayer **layer,
int (**rcv_func)(struct sk_buff *, struct net_device *,
@@ -314,11 +314,12 @@ void caif_enroll_dev(struct net_device *
enum cfcnfg_phy_preference pref;
struct cfcnfg *cfg = get_cfcnfg(dev_net(dev));
struct caif_device_entry_list *caifdevs;
+ int res;

caifdevs = caif_device_list(dev_net(dev));
caifd = caif_device_alloc(dev);
if (!caifd)
- return;
+ return -ENOMEM;
*layer = &caifd->layer;
spin_lock_init(&caifd->flow_lock);

@@ -339,7 +340,7 @@ void caif_enroll_dev(struct net_device *
strlcpy(caifd->layer.name, dev->name,
sizeof(caifd->layer.name));
caifd->layer.transmit = transmit;
- cfcnfg_add_phy_layer(cfg,
+ res = cfcnfg_add_phy_layer(cfg,
dev,
&caifd->layer,
pref,
@@ -349,6 +350,7 @@ void caif_enroll_dev(struct net_device *
mutex_unlock(&caifdevs->lock);
if (rcv_func)
*rcv_func = receive;
+ return res;
}
EXPORT_SYMBOL(caif_enroll_dev);

--- a/net/caif/cfcnfg.c
+++ b/net/caif/cfcnfg.c
@@ -450,7 +450,7 @@ unlock:
rcu_read_unlock();
}

-void
+int
cfcnfg_add_phy_layer(struct cfcnfg *cnfg,
struct net_device *dev, struct cflayer *phy_layer,
enum cfcnfg_phy_preference pref,
@@ -459,7 +459,7 @@ cfcnfg_add_phy_layer(struct cfcnfg *cnfg
{
struct cflayer *frml;
struct cfcnfg_phyinfo *phyinfo = NULL;
- int i;
+ int i, res = 0;
u8 phyid;

mutex_lock(&cnfg->lock);
@@ -473,12 +473,15 @@ cfcnfg_add_phy_layer(struct cfcnfg *cnfg
goto got_phyid;
}
pr_warn("Too many CAIF Link Layers (max 6)\n");
+ res = -EEXIST;
goto out;

got_phyid:
phyinfo = kzalloc(sizeof(struct cfcnfg_phyinfo), GFP_ATOMIC);
- if (!phyinfo)
+ if (!phyinfo) {
+ res = -ENOMEM;
goto out_err;
+ }

phy_layer->id = phyid;
phyinfo->pref = pref;
@@ -492,8 +495,10 @@ got_phyid:

frml = cffrml_create(phyid, fcs);

- if (!frml)
+ if (!frml) {
+ res = -ENOMEM;
goto out_err;
+ }
phyinfo->frm_layer = frml;
layer_set_up(frml, cnfg->mux);

@@ -511,11 +516,12 @@ got_phyid:
list_add_rcu(&phyinfo->node, &cnfg->phys);
out:
mutex_unlock(&cnfg->lock);
- return;
+ return res;

out_err:
kfree(phyinfo);
mutex_unlock(&cnfg->lock);
+ return res;
}
EXPORT_SYMBOL(cfcnfg_add_phy_layer);