diff options
| author | Reshetova, Elena <elena.reshetova@intel.com> | 2017-06-30 13:07:58 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-07-01 07:39:07 -0700 |
| commit | 633547973ffc32fd2c815639d4675e1531f0896f (patch) | |
| tree | 751ca7a379366af93f578d9f35f48339d4d2dd9b /net/core/dev.c | |
| parent | 53869cebce4bc53f71a080e7830600d4ae1ab712 (diff) | |
| download | lwn-633547973ffc32fd2c815639d4675e1531f0896f.tar.gz lwn-633547973ffc32fd2c815639d4675e1531f0896f.zip | |
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>
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 88927f1a3e4f..b9994898d11b 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1862,7 +1862,7 @@ static inline int deliver_skb(struct sk_buff *skb, { if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC))) return -ENOMEM; - atomic_inc(&skb->users); + refcount_inc(&skb->users); return pt_prev->func(skb, skb->dev, pt_prev, orig_dev); } @@ -2484,10 +2484,10 @@ void __dev_kfree_skb_irq(struct sk_buff *skb, enum skb_free_reason reason) if (unlikely(!skb)) return; - if (likely(atomic_read(&skb->users) == 1)) { + if (likely(refcount_read(&skb->users) == 1)) { smp_rmb(); - atomic_set(&skb->users, 0); - } else if (likely(!atomic_dec_and_test(&skb->users))) { + refcount_set(&skb->users, 0); + } else if (likely(!refcount_dec_and_test(&skb->users))) { return; } get_kfree_skb_cb(skb)->reason = reason; @@ -3955,7 +3955,7 @@ static __latent_entropy void net_tx_action(struct softirq_action *h) clist = clist->next; - WARN_ON(atomic_read(&skb->users)); + WARN_ON(refcount_read(&skb->users)); if (likely(get_kfree_skb_cb(skb)->reason == SKB_REASON_CONSUMED)) trace_consume_skb(skb); else |