1 files changed, 22 insertions, 15 deletions

diff --git a/ipc/shm.c b/ipc/shm.c
index 02ecf2c078fc..b76be5bda6c2 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -870,9 +870,7 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
         case SHM_LOCK:
         case SHM_UNLOCK:
         {
-                struct file *uninitialized_var(shm_file);
-
-                lru_add_drain_all();  /* drain pagevecs to lru lists */
+                struct file *shm_file;
 
                 shp = shm_lock_check(ns, shmid);
                 if (IS_ERR(shp)) {
@@ -895,22 +893,31 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf)
                 err = security_shm_shmctl(shp, cmd);
                 if (err)
                         goto out_unlock;
-                
-                if(cmd==SHM_LOCK) {
+
+                shm_file = shp->shm_file;
+                if (is_file_hugepages(shm_file))
+                        goto out_unlock;
+
+                if (cmd == SHM_LOCK) {
                         struct user_struct *user = current_user();
-                        if (!is_file_hugepages(shp->shm_file)) {
-                                err = shmem_lock(shp->shm_file, 1, user);
-                                if (!err && !(shp->shm_perm.mode & SHM_LOCKED)){
-                                        shp->shm_perm.mode |= SHM_LOCKED;
-                                        shp->mlock_user = user;
-                                }
+                        err = shmem_lock(shm_file, 1, user);
+                        if (!err && !(shp->shm_perm.mode & SHM_LOCKED)) {
+                                shp->shm_perm.mode |= SHM_LOCKED;
+                                shp->mlock_user = user;
                         }
-                } else if (!is_file_hugepages(shp->shm_file)) {
-                        shmem_lock(shp->shm_file, 0, shp->mlock_user);
-                        shp->shm_perm.mode &= ~SHM_LOCKED;
-                        shp->mlock_user = NULL;
+                        goto out_unlock;
                 }
+
+                /* SHM_UNLOCK */
+                if (!(shp->shm_perm.mode & SHM_LOCKED))
+                        goto out_unlock;
+                shmem_lock(shm_file, 0, shp->mlock_user);
+                shp->shm_perm.mode &= ~SHM_LOCKED;
+                shp->mlock_user = NULL;
+                get_file(shm_file);
                 shm_unlock(shp);
+                shmem_unlock_mapping(shm_file->f_mapping);
+                fput(shm_file);
                 goto out;
         }
         case IPC_RMID: