Commit c0acdfb4 authored by Reshetova, Elena's avatar Reshetova, Elena Committed by David S. Miller
Browse files

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: 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 6871584a

include/net/sctp/structs.h

+1 −1
Original line number Original line Diff line number Diff line
@@ -496,7 +496,7 @@ struct sctp_datamsg { 
	/* Chunks waiting to be submitted to lower layer. */

	/* Chunks waiting to be submitted to lower layer. */

	struct list_head chunks;

	struct list_head chunks;

	/* Reference counting. */

	/* Reference counting. */

	atomic_t refcnt;

	refcount_t refcnt;

	/* When is this message no longer interesting to the peer? */

	/* When is this message no longer interesting to the peer? */

	unsigned long expires_at;

	unsigned long expires_at;

	/* Did the messenge fail to send? */

	/* Did the messenge fail to send? */

net/sctp/chunk.c

+3 −3
Original line number Original line Diff line number Diff line
@@ -49,7 +49,7 @@ 
/* Initialize datamsg from memory. */

/* Initialize datamsg from memory. */

static void sctp_datamsg_init(struct sctp_datamsg *msg)

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_failed = 0;

	msg->send_error = 0;

	msg->send_error = 0;

	msg->can_delay = 1;

	msg->can_delay = 1;
@@ -136,13 +136,13 @@ static void sctp_datamsg_destroy(struct sctp_datamsg *msg) 
/* Hold a reference. */

/* Hold a reference. */

static void sctp_datamsg_hold(struct sctp_datamsg *msg)

static void sctp_datamsg_hold(struct sctp_datamsg *msg)

{

{

	atomic_inc(&msg->refcnt);

	refcount_inc(&msg->refcnt);

}

}





/* Release a reference. */

/* Release a reference. */

void sctp_datamsg_put(struct sctp_datamsg *msg)

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);

		sctp_datamsg_destroy(msg);

}

}

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