From: Jason Gunthorpe <jgg@ziepe.ca>
To: "Christian König" <ckoenig.leichtzumerken@gmail.com>
Cc: jhubbard@nvidia.com, linux-kernel@vger.kernel.org,
dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk,
linaro-mm-sig@lists.linaro.org, linux-mm@kvack.org,
willy@infradead.org, airlied@redhat.com,
akpm@linux-foundation.org, linux-media@vger.kernel.org
Subject: Re: [PATCH 1/6] mm: mmap: fix fput in error path
Date: Fri, 9 Oct 2020 12:15:40 -0300 [thread overview]
Message-ID: <20201009151540.GX5177@ziepe.ca> (raw)
In-Reply-To: <20201009150342.1979-1-christian.koenig@amd.com>
On Fri, Oct 09, 2020 at 05:03:37PM +0200, Christian König wrote:
> 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.
>
> Signed-off-by: Christian König <christian.koenig@amd.com>
> drivers/dma-buf/dma-buf.c | 22 +++++-----------------
> mm/mmap.c | 2 +-
> 2 files changed, 6 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
> index a6ba4d598f0e..edd57402a48a 100644
> +++ b/drivers/dma-buf/dma-buf.c
> @@ -1143,9 +1143,6 @@ 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;
>
> @@ -1163,22 +1160,13 @@ 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;
> - vma->vm_pgoff = pgoff;
> + if (vma->vm_file)
> + fput(vma->vm_file);
This if is redundant too
But otherwise
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Thanks,
Jason
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next prev parent reply other threads:[~2020-10-10 10:03 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-09 15:03 [PATCH 1/6] mm: mmap: fix fput in error path Christian König
2020-10-09 15:03 ` [PATCH 2/6] mm: introduce vma_set_file function v3 Christian König
2020-10-09 15:14 ` Jason Gunthorpe
2020-10-12 8:11 ` Christian König
2020-10-09 15:03 ` [PATCH 3/6] drm/radeon: stop using pages with drm_prime_sg_to_page_addr_arrays Christian König
2020-10-09 15:03 ` [PATCH 4/6] drm/amdgpu: " Christian König
2020-10-09 15:03 ` [PATCH 5/6] drm/nouveau: " Christian König
2020-10-09 15:03 ` [PATCH 6/6] drm/prime: document that use the page array is deprecated v2 Christian König
2020-10-09 16:24 ` Daniel Vetter
2020-10-09 16:27 ` Daniel Vetter
2020-10-09 15:15 ` Jason Gunthorpe [this message]
2020-10-09 22:04 ` [PATCH 1/6] mm: mmap: fix fput in error path Andrew Morton
2020-10-09 22:25 ` Jason Gunthorpe
2020-10-12 8:13 ` Christian König
2020-10-10 1:48 linmiaohe
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