diff options
| author | Christian König <christian.koenig@amd.com> | 2020-10-09 15:08:55 +0200 |
|---|---|---|
| committer | Christian König <christian.koenig@amd.com> | 2020-11-19 10:35:58 +0100 |
| commit | 1527f926fd04490f648c42f42b45218a04754f87 (patch) | |
| tree | f817599287173a78196d50eacde0320a553d7289 | |
| parent | f9f92e7c583f9b120bbb09edae6a587b73feb3a9 (diff) | |
| download | linux-1527f926fd04490f648c42f42b45218a04754f87.tar.bz2 | |
mm: mmap: fix fput in error path v2
Patch "495c10cc1c0c CHROMIUM: dma-buf: restore args..."
adds a workaround for a bug in mmap_region.
As the comment states ->mmap() callback can change
vma->vm_file and so we might call fput() on the wrong file.
Revert the workaround and proper fix this in mmap_region.
v2: drop the extra if in dma_buf_mmap as well
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://patchwork.freedesktop.org/patch/399359/
| -rw-r--r-- | drivers/dma-buf/dma-buf.c | 20 | ||||
| -rw-r--r-- | mm/mmap.c | 2 |
2 files changed, 4 insertions, 18 deletions
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 0eb80c1ecdab..282bd8b84170 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -1166,9 +1166,6 @@ EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access); 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; @@ -1186,22 +1183,11 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma, return -EINVAL; /* readjust the vma */ - get_file(dmabuf->file); - oldfile = vma->vm_file; - vma->vm_file = dmabuf->file; + fput(vma->vm_file); + vma->vm_file = get_file(dmabuf->file); vma->vm_pgoff = pgoff; - 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; - + return dmabuf->ops->mmap(dmabuf, vma); } EXPORT_SYMBOL_GPL(dma_buf_mmap); diff --git a/mm/mmap.c b/mm/mmap.c index d91ecb00d38c..30a4e8412a58 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1899,8 +1899,8 @@ out: return addr; unmap_and_free_vma: + fput(vma->vm_file); vma->vm_file = NULL; - fput(file); /* Undo any partial mapping done by a device driver. */ unmap_region(mm, vma, prev, vma->vm_start, vma->vm_end); |