From 495c10cc1c0c359871d5bef32dd173252fc17995 Mon Sep 17 00:00:00 2001 From: John Sheu Date: Mon, 11 Feb 2013 17:50:24 -0800 Subject: [PATCH] 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 Reviewed-by: Daniel Vetter Signed-off-by: Sumit Semwal --- drivers/base/dma-buf.c | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c index 394523807a6d..2a7cb0df176b 100644 --- a/drivers/base/dma-buf.c +++ b/drivers/base/dma-buf.c @@ -447,6 +447,9 @@ EXPORT_SYMBOL_GPL(dma_buf_kunmap); 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 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, 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); -- GitLab