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>
diff --git a/net/rds/message.c b/net/rds/message.c
index 49bfb51..4318cc9 100644
--- a/net/rds/message.c
+++ b/net/rds/message.c
@@ -48,8 +48,8 @@
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 @@
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 @@
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);
diff --git a/net/rds/rds.h b/net/rds/rds.h
index ea72d6e..516bcc8 100644
--- a/net/rds/rds.h
+++ b/net/rds/rds.h
@@ -356,7 +356,7 @@
#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;