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@xxxxxxxxx>
Signed-off-by: Hans Liljestrand <ishkamiel@xxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: David Windsor <dwindsor@xxxxxxxxx>
---
net/sunrpc/auth_gss/auth_gss.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 72f129c..e7c941a 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -287,7 +287,7 @@ gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct
#define UPCALL_BUF_LEN 128
struct gss_upcall_msg {
- atomic_t count;
+ refcount_t count;
kuid_t uid;
struct rpc_pipe_msg msg;
struct list_head list;
@@ -328,7 +328,7 @@ static void
gss_release_msg(struct gss_upcall_msg *gss_msg)
{
struct net *net = gss_msg->auth->net;
- if (!atomic_dec_and_test(&gss_msg->count))
+ if (!refcount_dec_and_test(&gss_msg->count))
return;
put_pipe_version(net);
BUG_ON(!list_empty(&gss_msg->list));
@@ -348,7 +348,7 @@ __gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid, const struct gss_auth *auth
continue;
if (auth && pos->auth->service != auth->service)
continue;
- atomic_inc(&pos->count);
+ refcount_inc(&pos->count);
dprintk("RPC: %s found msg %p\n", __func__, pos);
return pos;
}
@@ -369,7 +369,7 @@ gss_add_msg(struct gss_upcall_msg *gss_msg)
spin_lock(&pipe->lock);
old = __gss_find_upcall(pipe, gss_msg->uid, gss_msg->auth);
if (old == NULL) {
- atomic_inc(&gss_msg->count);
+ refcount_inc(&gss_msg->count);
list_add(&gss_msg->list, &pipe->in_downcall);
} else
gss_msg = old;
@@ -383,7 +383,7 @@ __gss_unhash_msg(struct gss_upcall_msg *gss_msg)
list_del_init(&gss_msg->list);
rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
wake_up_all(&gss_msg->waitqueue);
- atomic_dec(&gss_msg->count);
+ WARN_ON(refcount_dec_and_test(&gss_msg->count));
}
static void
@@ -506,7 +506,7 @@ gss_alloc_msg(struct gss_auth *gss_auth,
INIT_LIST_HEAD(&gss_msg->list);
rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
init_waitqueue_head(&gss_msg->waitqueue);
- atomic_set(&gss_msg->count, 1);
+ refcount_set(&gss_msg->count, 1);
gss_msg->uid = uid;
gss_msg->auth = gss_auth;
switch (vers) {
@@ -542,11 +542,11 @@ gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred)
gss_msg = gss_add_msg(gss_new);
if (gss_msg == gss_new) {
int res;
- atomic_inc(&gss_msg->count);
+ refcount_inc(&gss_msg->count);
res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
if (res) {
gss_unhash_msg(gss_new);
- atomic_dec(&gss_msg->count);
+ refcount_dec(&gss_msg->count);
gss_release_msg(gss_new);
gss_msg = ERR_PTR(res);
}
@@ -595,7 +595,7 @@ gss_refresh_upcall(struct rpc_task *task)
task->tk_timeout = 0;
gss_cred->gc_upcall = gss_msg;
/* gss_upcall_callback will release the reference to gss_upcall_msg */
- atomic_inc(&gss_msg->count);
+ refcount_inc(&gss_msg->count);
rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
} else {
gss_handle_downcall_result(gss_cred, gss_msg);
@@ -815,7 +815,7 @@ gss_pipe_release(struct inode *inode)
if (!list_empty(&gss_msg->msg.list))
continue;
gss_msg->msg.errno = -EPIPE;
- atomic_inc(&gss_msg->count);
+ refcount_inc(&gss_msg->count);
__gss_unhash_msg(gss_msg);
spin_unlock(&pipe->lock);
gss_release_msg(gss_msg);
@@ -834,7 +834,7 @@ gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
if (msg->errno < 0) {
dprintk("RPC: %s releasing msg %p\n",
__func__, gss_msg);
- atomic_inc(&gss_msg->count);
+ refcount_inc(&gss_msg->count);
gss_unhash_msg(gss_msg);
if (msg->errno == -ETIMEDOUT)
warn_gssd();
--
2.7.4
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