userfaultfd: add missing mmput() in error path

This fixes a memleak if anon_inode_getfile() fails in userfaultfd().

Signed-off-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 634e676072cb..f9aeb40a7197 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -1287,8 +1287,10 @@ static struct file *userfaultfd_file_create(int flags)
 
         file = anon_inode_getfile("[userfaultfd]", &userfaultfd_fops, ctx,
                                   O_RDWR | (flags & UFFD_SHARED_FCNTL_FLAGS));
-        if (IS_ERR(file))
+        if (IS_ERR(file)) {
+                mmput(ctx->mm);
                 kmem_cache_free(userfaultfd_ctx_cachep, ctx);
+        }
 out:
         return file;
 }