net, atm: convert in_cache_entry.use from atomic_t to refcount_t

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@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Reshetova, Elena 2017-07-04 15:53:03 +03:00 committed by David S. Miller
parent 788936641a
commit 9371491254
2 changed files with 8 additions and 7 deletions

View File

@ -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);
}

View File

@ -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{