net, sctp: convert sctp_chunk.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 15:53:26 +03:00 committed by David S. Miller
parent c0acdfb409
commit e7f0279617
2 changed files with 4 additions and 4 deletions

View File

@ -524,7 +524,7 @@ int sctp_chunk_abandoned(struct sctp_chunk *);
struct sctp_chunk {
struct list_head list;
atomic_t refcnt;
refcount_t refcnt;
/* How many times this chunk have been sent, for prsctp RTX policy */
int sent_count;

View File

@ -1345,7 +1345,7 @@ struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
INIT_LIST_HEAD(&retval->transmitted_list);
INIT_LIST_HEAD(&retval->frag_list);
SCTP_DBG_OBJCNT_INC(chunk);
atomic_set(&retval->refcnt, 1);
refcount_set(&retval->refcnt, 1);
nodata:
return retval;
@ -1458,13 +1458,13 @@ void sctp_chunk_free(struct sctp_chunk *chunk)
/* Grab a reference to the chunk. */
void sctp_chunk_hold(struct sctp_chunk *ch)
{
atomic_inc(&ch->refcnt);
refcount_inc(&ch->refcnt);
}
/* Release a reference to the chunk. */
void sctp_chunk_put(struct sctp_chunk *ch)
{
if (atomic_dec_and_test(&ch->refcnt))
if (refcount_dec_and_test(&ch->refcnt))
sctp_chunk_destroy(ch);
}