Re: [Linaro-mm-sig] [PATCH 1/2] mm: mmap: fix fput in error path v2

On Mon, Oct 12, 2020 at 10:52:02AM +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.

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

---

drivers/dma-buf/dma-buf.c | 20 +++----------------- mm/mmap.c | 2 +- 2 files changed, 4 insertions(+), 18 deletions(-)

Reviewed-by: Jason Gunthorpe jgg@nvidia.com

Probably should Fixes that other patch Andrew pointed at

Jason