net, rds: convert rds_message.m_refcount 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 15:53:18 +03:00 committed by David S. Miller
parent 803ea85053
commit 6c5a1c4a2a
2 changed files with 7 additions and 7 deletions

View File

@ -48,8 +48,8 @@ static unsigned int rds_exthdr_size[__RDS_EXTHDR_MAX] = {
void rds_message_addref(struct rds_message *rm)
{
rdsdebug("addref rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));
atomic_inc(&rm->m_refcount);
rdsdebug("addref rm %p ref %d\n", rm, refcount_read(&rm->m_refcount));
refcount_inc(&rm->m_refcount);
}
EXPORT_SYMBOL_GPL(rds_message_addref);
@ -83,9 +83,9 @@ static void rds_message_purge(struct rds_message *rm)
void rds_message_put(struct rds_message *rm)
{
rdsdebug("put rm %p ref %d\n", rm, atomic_read(&rm->m_refcount));
WARN(!atomic_read(&rm->m_refcount), "danger refcount zero on %p\n", rm);
if (atomic_dec_and_test(&rm->m_refcount)) {
rdsdebug("put rm %p ref %d\n", rm, refcount_read(&rm->m_refcount));
WARN(!refcount_read(&rm->m_refcount), "danger refcount zero on %p\n", rm);
if (refcount_dec_and_test(&rm->m_refcount)) {
BUG_ON(!list_empty(&rm->m_sock_item));
BUG_ON(!list_empty(&rm->m_conn_item));
rds_message_purge(rm);
@ -206,7 +206,7 @@ struct rds_message *rds_message_alloc(unsigned int extra_len, gfp_t gfp)
rm->m_used_sgs = 0;
rm->m_total_sgs = extra_len / sizeof(struct scatterlist);
atomic_set(&rm->m_refcount, 1);
refcount_set(&rm->m_refcount, 1);
INIT_LIST_HEAD(&rm->m_sock_item);
INIT_LIST_HEAD(&rm->m_conn_item);
spin_lock_init(&rm->m_rs_lock);

View File

@ -356,7 +356,7 @@ static inline u32 rds_rdma_cookie_offset(rds_rdma_cookie_t cookie)
#define RDS_MSG_FLUSH 8
struct rds_message {
atomic_t m_refcount;
refcount_t m_refcount;
struct list_head m_sock_item;
struct list_head m_conn_item;
struct rds_incoming m_inc;