From 6c5a1c4a2afdcc21434b86996b49460f07ee69a3 Mon Sep 17 00:00:00 2001 From: "Reshetova, Elena" Date: Tue, 4 Jul 2017 15:53:18 +0300 Subject: [PATCH] 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 Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor Signed-off-by: David S. Miller --- net/rds/message.c | 12 ++++++------ net/rds/rds.h | 2 +- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/net/rds/message.c b/net/rds/message.c index 49bfb512d808..4318cc9b78f7 100644 --- a/net/rds/message.c +++ b/net/rds/message.c @@ -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); diff --git a/net/rds/rds.h b/net/rds/rds.h index ea72d6e33c14..516bcc89b46f 100644 --- a/net/rds/rds.h +++ b/net/rds/rds.h @@ -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; -- 2.20.1