net: convert sk_buff.users 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>
diff --git a/drivers/s390/net/netiucv.c b/drivers/s390/net/netiucv.c
index 7db427c..1579695 100644
--- a/drivers/s390/net/netiucv.c
+++ b/drivers/s390/net/netiucv.c
@@ -743,7 +743,7 @@
conn->prof.tx_pending--;
if (single_flag) {
if ((skb = skb_dequeue(&conn->commit_queue))) {
- atomic_dec(&skb->users);
+ refcount_dec(&skb->users);
if (privptr) {
privptr->stats.tx_packets++;
privptr->stats.tx_bytes +=
@@ -766,7 +766,7 @@
txbytes += skb->len;
txpackets++;
stat_maxcq++;
- atomic_dec(&skb->users);
+ refcount_dec(&skb->users);
dev_kfree_skb_any(skb);
}
if (conn->collect_len > conn->prof.maxmulti)
@@ -958,7 +958,7 @@
struct sk_buff *skb;
while ((skb = skb_dequeue(q))) {
- atomic_dec(&skb->users);
+ refcount_dec(&skb->users);
dev_kfree_skb_any(skb);
}
}
@@ -1176,7 +1176,7 @@
IUCV_DBF_TEXT(data, 2,
"EBUSY from netiucv_transmit_skb\n");
} else {
- atomic_inc(&skb->users);
+ refcount_inc(&skb->users);
skb_queue_tail(&conn->collect_queue, skb);
conn->collect_len += l;
rc = 0;
@@ -1245,7 +1245,7 @@
} else {
if (copied)
dev_kfree_skb(skb);
- atomic_inc(&nskb->users);
+ refcount_inc(&nskb->users);
skb_queue_tail(&conn->commit_queue, nskb);
}
}