CHROMIUM: dma-buf: restore args on failure of dma_buf_mmap
Callers to dma_buf_mmap expect to fput() the vma struct's vm_file
themselves on failure. Not restoring the struct's data on failure
causes a double-decrement of the vm_file's refcount.
Signed-off-by: John Sheu <sheu@google.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c
index 3945238..2a7cb0d 100644
--- a/drivers/base/dma-buf.c
+++ b/drivers/base/dma-buf.c
@@ -447,6 +447,9 @@
int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
unsigned long pgoff)
{
+ struct file *oldfile;
+ int ret;
+
if (WARN_ON(!dmabuf || !vma))
return -EINVAL;
@@ -460,14 +463,22 @@
return -EINVAL;
/* readjust the vma */
- if (vma->vm_file)
- fput(vma->vm_file);
-
- vma->vm_file = get_file(dmabuf->file);
-
+ get_file(dmabuf->file);
+ oldfile = vma->vm_file;
+ vma->vm_file = dmabuf->file;
vma->vm_pgoff = pgoff;
- return dmabuf->ops->mmap(dmabuf, vma);
+ ret = dmabuf->ops->mmap(dmabuf, vma);
+ if (ret) {
+ /* restore old parameters on failure */
+ vma->vm_file = oldfile;
+ fput(dmabuf->file);
+ } else {
+ if (oldfile)
+ fput(oldfile);
+ }
+ return ret;
+
}
EXPORT_SYMBOL_GPL(dma_buf_mmap);