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Commit e7f02796 authored by Reshetova, Elena's avatar Reshetova, Elena Committed by David S. Miller
Browse files

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: default avatarElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: default avatarHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarDavid Windsor <dwindsor@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c0acdfb4

include/net/sctp/structs.h

+1 −1
Original line number Diff line number Diff line
@@ -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;

net/sctp/sm_make_chunk.c

+3 −3
Original line number Diff line number Diff line
@@ -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);

}