[patch 1/5] coda: fix reference counting in coda_file_mmap error path

[patch 1/5] coda: fix reference counting in coda_file_mmap error path

[Andrew Morton]

From: Christian König <christian.koenig@amd.com>
Subject: coda: fix reference counting in coda_file_mmap error path

mmap_region() now calls fput() on the vma->vm_file.

So we need to drop the extra reference on the coda file instead of the
host file.

Link: https://lkml.kernel.org/r/20210421132012.82354-1-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>
Acked-by: 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>
---

 fs/coda/file.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/fs/coda/file.c~coda-fix-reference-counting-in-coda_file_mmap-error-path
+++ a/fs/coda/file.c
@@ -175,10 +175,10 @@ coda_file_mmap(struct file *coda_file, s
 	ret = call_mmap(vma->vm_file, vma);
 
 	if (ret) {
-		/* if call_mmap fails, our caller will put coda_file so we
-		 * should drop the reference to the host_file that we got.
+		/* if call_mmap fails, our caller will put host_file so we
+		 * should drop the reference to the coda_file that we got.
 		 */
-		fput(host_file);
+		fput(coda_file);
 		kfree(cvm_ops);
 	} else {
 		/* here we add redirects for the open/close vm_operations */
_

[patch 2/5] ovl: fix reference counting in ovl_mmap error path

[Andrew Morton]

From: Christian König <christian.koenig@amd.com>
Subject: ovl: fix reference counting in ovl_mmap error path

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>
---

 fs/overlayfs/file.c |   11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

--- a/fs/overlayfs/file.c~ovl-fix-reference-counting-in-ovl_mmap-error-path
+++ a/fs/overlayfs/file.c
@@ -430,20 +430,11 @@ static int ovl_mmap(struct file *file, s
 	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;
_