From c1d1b437816f0afa99202be3cb650c9d174667bc Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 31 Aug 2017 16:48:22 -0700 Subject: net: convert (struct ubuf_info)->refcnt 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. v2: added the change in drivers/vhost/net.c as spotted by Willem. Signed-off-by: Eric Dumazet Acked-by: Willem de Bruijn Signed-off-by: David S. Miller --- net/core/skbuff.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/core/skbuff.c b/net/core/skbuff.c index a003f953a0a6..68065d7d383f 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -963,7 +963,7 @@ struct ubuf_info *sock_zerocopy_alloc(struct sock *sk, size_t size) uarg->len = 1; uarg->bytelen = size; uarg->zerocopy = 1; - atomic_set(&uarg->refcnt, 1); + refcount_set(&uarg->refcnt, 1); sock_hold(sk); return uarg; @@ -1086,7 +1086,7 @@ EXPORT_SYMBOL_GPL(sock_zerocopy_callback); void sock_zerocopy_put(struct ubuf_info *uarg) { - if (uarg && atomic_dec_and_test(&uarg->refcnt)) { + if (uarg && refcount_dec_and_test(&uarg->refcnt)) { if (uarg->callback) uarg->callback(uarg, uarg->zerocopy); else @@ -1483,7 +1483,7 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, if (skb_orphan_frags(skb, gfp_mask)) goto nofrags; if (skb_zcopy(skb)) - atomic_inc(&skb_uarg(skb)->refcnt); + refcount_inc(&skb_uarg(skb)->refcnt); for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) skb_frag_ref(skb, i); -- cgit v1.2.3