From 14afee4b6092fde451ee17604e5f5c89da33e71e Mon Sep 17 00:00:00 2001 From: "Reshetova, Elena" Date: Fri, 30 Jun 2017 13:08:00 +0300 Subject: net: convert sock.sk_wmem_alloc 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 Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor Signed-off-by: David S. Miller --- net/atm/mpc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/atm/mpc.c') diff --git a/net/atm/mpc.c b/net/atm/mpc.c index a190800572bd..680a4b9095a1 100644 --- a/net/atm/mpc.c +++ b/net/atm/mpc.c @@ -555,7 +555,7 @@ static int send_via_shortcut(struct sk_buff *skb, struct mpoa_client *mpc) sizeof(struct llc_snap_hdr)); } - atomic_add(skb->truesize, &sk_atm(entry->shortcut)->sk_wmem_alloc); + refcount_add(skb->truesize, &sk_atm(entry->shortcut)->sk_wmem_alloc); ATM_SKB(skb)->atm_options = entry->shortcut->atm_options; entry->shortcut->send(entry->shortcut, skb); entry->packets_fwded++; @@ -911,7 +911,7 @@ static int msg_from_mpoad(struct atm_vcc *vcc, struct sk_buff *skb) struct mpoa_client *mpc = find_mpc_by_vcc(vcc); struct k_message *mesg = (struct k_message *)skb->data; - atomic_sub(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc); + WARN_ON(refcount_sub_and_test(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc)); if (mpc == NULL) { pr_info("no mpc found\n"); -- cgit v1.2.3-58-ga151