net, sctp: convert sctp_datamsg.refcnt 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>
This commit is contained in:
Reshetova, Elena 2017-07-04 15:53:25 +03:00 committed by David S. Miller
parent 6871584a5e
commit c0acdfb409
2 changed files with 4 additions and 4 deletions

View File

@ -496,7 +496,7 @@ struct sctp_datamsg {
/* Chunks waiting to be submitted to lower layer. */
struct list_head chunks;
/* Reference counting. */
atomic_t refcnt;
refcount_t refcnt;
/* When is this message no longer interesting to the peer? */
unsigned long expires_at;
/* Did the messenge fail to send? */

View File

@ -49,7 +49,7 @@
/* Initialize datamsg from memory. */
static void sctp_datamsg_init(struct sctp_datamsg *msg)
{
atomic_set(&msg->refcnt, 1);
refcount_set(&msg->refcnt, 1);
msg->send_failed = 0;
msg->send_error = 0;
msg->can_delay = 1;
@ -136,13 +136,13 @@ static void sctp_datamsg_destroy(struct sctp_datamsg *msg)
/* Hold a reference. */
static void sctp_datamsg_hold(struct sctp_datamsg *msg)
{
atomic_inc(&msg->refcnt);
refcount_inc(&msg->refcnt);
}
/* Release a reference. */
void sctp_datamsg_put(struct sctp_datamsg *msg)
{
if (atomic_dec_and_test(&msg->refcnt))
if (refcount_dec_and_test(&msg->refcnt))
sctp_datamsg_destroy(msg);
}