From 2896900e22f8212606a1837d89a6bbce314ceeda Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>
Date: Fri, 23 Apr 2021 14:28:54 -0700
Subject: [PATCH] ovl: fix reference counting in ovl_mmap error path
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mmap_region() now calls fput() on the vma->vm_file.
Fix this by using vma_set_file() so it doesn't need to be handled
manually here any more.
Link: https://lkml.kernel.org/r/20210421132012.82354-2-christian.koenig@amd.com
Fixes: 1527f926fd04 ("mm: mmap: fix fput in error path v2")
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jan Harkes <jaharkes@cs.cmu.edu>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: <stable@vger.kernel.org> [5.11+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/overlayfs/file.c | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index dbfb35fb0ff7..3847cdc069b5 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -430,20 +430,11 @@ static int ovl_mmap(struct file *file, struct vm_area_struct *vma)
if (WARN_ON(file != vma->vm_file))
return -EIO;
- vma->vm_file = get_file(realfile);
+ vma_set_file(vma, realfile);
old_cred = ovl_override_creds(file_inode(file)->i_sb);
ret = call_mmap(vma->vm_file, vma);
revert_creds(old_cred);
-
- if (ret) {
- /* Drop reference count from new vm_file value */
- fput(realfile);
- } else {
- /* Drop reference count from previous vm_file value */
- fput(file);
- }
-
ovl_file_accessed(file);
return ret;