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authorReshetova, Elena <elena.reshetova@intel.com>2017-06-30 13:08:10 +0300
committerDavid S. Miller <davem@davemloft.net>2017-07-01 07:39:09 -0700
commitfb5c2c17a556d9b00798d6a6b9e624281ee2eb28 (patch)
treedff0f8eeadd7672b0d3ded973afe02bb02f75a8c /net/packet
parentb4217b82893c23f9f45f77914b5aa3b662b75332 (diff)
net: convert packet_fanout.sk_ref 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>
Diffstat (limited to 'net/packet')
-rw-r--r--net/packet/af_packet.c8
-rw-r--r--net/packet/internal.h4
2 files changed, 7 insertions, 5 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 643302b37b48..e3beb28203eb 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1739,7 +1739,7 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
match->flags = flags;
INIT_LIST_HEAD(&match->list);
spin_lock_init(&match->lock);
- atomic_set(&match->sk_ref, 0);
+ refcount_set(&match->sk_ref, 0);
fanout_init_data(match);
match->prot_hook.type = po->prot_hook.type;
match->prot_hook.dev = po->prot_hook.dev;
@@ -1753,10 +1753,10 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
match->prot_hook.type == po->prot_hook.type &&
match->prot_hook.dev == po->prot_hook.dev) {
err = -ENOSPC;
- if (atomic_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
+ if (refcount_read(&match->sk_ref) < PACKET_FANOUT_MAX) {
__dev_remove_pack(&po->prot_hook);
po->fanout = match;
- atomic_inc(&match->sk_ref);
+ refcount_set(&match->sk_ref, refcount_read(&match->sk_ref) + 1);
__fanout_link(sk, po);
err = 0;
}
@@ -1785,7 +1785,7 @@ static struct packet_fanout *fanout_release(struct sock *sk)
if (f) {
po->fanout = NULL;
- if (atomic_dec_and_test(&f->sk_ref))
+ if (refcount_dec_and_test(&f->sk_ref))
list_del(&f->list);
else
f = NULL;
diff --git a/net/packet/internal.h b/net/packet/internal.h
index 9ee46314b7d7..94d1d405a116 100644
--- a/net/packet/internal.h
+++ b/net/packet/internal.h
@@ -1,6 +1,8 @@
#ifndef __PACKET_INTERNAL_H__
#define __PACKET_INTERNAL_H__
+#include <linux/refcount.h>
+
struct packet_mclist {
struct packet_mclist *next;
int ifindex;
@@ -86,7 +88,7 @@ struct packet_fanout {
struct list_head list;
struct sock *arr[PACKET_FANOUT_MAX];
spinlock_t lock;
- atomic_t sk_ref;
+ refcount_t sk_ref;
struct packet_type prot_hook ____cacheline_aligned_in_smp;
};