fix a struct file leak in do_mmap_pgoff()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 15 insertions, 0 deletions

diff --git a/mm/util.c b/mm/util.c
index 3bf81b294ae8..b377ce430803 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -280,9 +280,24 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
         unsigned long retval = -EBADF;
 
         if (!(flags & MAP_ANONYMOUS)) {
+                if (unlikely(flags & MAP_HUGETLB))
+                        return -EINVAL;
                 file = fget(fd);
                 if (!file)
                         goto out;
+        } else if (flags & MAP_HUGETLB) {
+                struct user_struct *user = NULL;
+                /*
+                 * VM_NORESERVE is used because the reservations will be
+                 * taken when vm_ops->mmap() is called
+                 * A dummy user value is used because we are not locking
+                 * memory so no accounting is necessary
+                 */
+                len = ALIGN(len, huge_page_size(&default_hstate));
+                file = hugetlb_file_setup(HUGETLB_ANON_FILE, len, VM_NORESERVE,
+                                                &user, HUGETLB_ANONHUGE_INODE);
+                if (IS_ERR(file))
+                        return PTR_ERR(file);
         }
 
         flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);