refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: Elena Reshetova <elena.reshetova@xxxxxxxxx>
Signed-off-by: Hans Liljestrand <ishkamiel@xxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: David Windsor <dwindsor@xxxxxxxxx>
---
net/atm/mpoa_caches.c | 12 ++++++------
net/atm/mpoa_caches.h | 3 ++-
2 files changed, 8 insertions(+), 7 deletions(-)
diff --git a/net/atm/mpoa_caches.c b/net/atm/mpoa_caches.c
index a89fdeb..05e89e9 100644
--- a/net/atm/mpoa_caches.c
+++ b/net/atm/mpoa_caches.c
@@ -40,7 +40,7 @@ static in_cache_entry *in_cache_get(__be32 dst_ip,
entry = client->in_cache;
while (entry != NULL) {
if (entry->ctrl_info.in_dst_ip == dst_ip) {
- atomic_inc(&entry->use);
+ refcount_inc(&entry->use);
read_unlock_bh(&client->ingress_lock);
return entry;
}
@@ -61,7 +61,7 @@ static in_cache_entry *in_cache_get_with_mask(__be32 dst_ip,
entry = client->in_cache;
while (entry != NULL) {
if ((entry->ctrl_info.in_dst_ip & mask) == (dst_ip & mask)) {
- atomic_inc(&entry->use);
+ refcount_inc(&entry->use);
read_unlock_bh(&client->ingress_lock);
return entry;
}
@@ -82,7 +82,7 @@ static in_cache_entry *in_cache_get_by_vcc(struct atm_vcc *vcc,
entry = client->in_cache;
while (entry != NULL) {
if (entry->shortcut == vcc) {
- atomic_inc(&entry->use);
+ refcount_inc(&entry->use);
read_unlock_bh(&client->ingress_lock);
return entry;
}
@@ -105,7 +105,7 @@ static in_cache_entry *in_cache_add_entry(__be32 dst_ip,
dprintk("adding an ingress entry, ip = %pI4\n", &dst_ip);
- atomic_set(&entry->use, 1);
+ refcount_set(&entry->use, 1);
dprintk("new_in_cache_entry: about to lock\n");
write_lock_bh(&client->ingress_lock);
entry->next = client->in_cache;
@@ -121,7 +121,7 @@ static in_cache_entry *in_cache_add_entry(__be32 dst_ip,
entry->count = 1;
entry->entry_state = INGRESS_INVALID;
entry->ctrl_info.holding_time = HOLDING_TIME_DEFAULT;
- atomic_inc(&entry->use);
+ refcount_inc(&entry->use);
write_unlock_bh(&client->ingress_lock);
dprintk("new_in_cache_entry: unlocked\n");
@@ -178,7 +178,7 @@ static int cache_hit(in_cache_entry *entry, struct mpoa_client *mpc)
static void in_cache_put(in_cache_entry *entry)
{
- if (atomic_dec_and_test(&entry->use)) {
+ if (refcount_dec_and_test(&entry->use)) {
memset(entry, 0, sizeof(in_cache_entry));
kfree(entry);
}
diff --git a/net/atm/mpoa_caches.h b/net/atm/mpoa_caches.h
index 8e5f78c..38a4e7e 100644
--- a/net/atm/mpoa_caches.h
+++ b/net/atm/mpoa_caches.h
@@ -6,6 +6,7 @@
#include <linux/atm.h>
#include <linux/atmdev.h>
#include <linux/atmmpc.h>
+#include <linux/refcount.h>
struct mpoa_client;
@@ -25,7 +26,7 @@ typedef struct in_cache_entry {
struct atm_vcc *shortcut;
uint8_t MPS_ctrl_ATM_addr[ATM_ESA_LEN];
struct in_ctrl_info ctrl_info;
- atomic_t use;
+ refcount_t use;
} in_cache_entry;
struct in_cache_ops{
--
2.7.4
--
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