diff options
| author | Reshetova, Elena <elena.reshetova@intel.com> | 2017-06-30 13:08:10 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-07-01 07:39:09 -0700 |
| commit | fb5c2c17a556d9b00798d6a6b9e624281ee2eb28 (patch) | |
| tree | dff0f8eeadd7672b0d3ded973afe02bb02f75a8c /net/packet | |
| parent | b4217b82893c23f9f45f77914b5aa3b662b75332 (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.c | 8 | ||||
| -rw-r--r-- | net/packet/internal.h | 4 |
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; }; |