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mm: mmap: fix fput in error path

PATCH linmiaohe 1 participant 1 message Oct 10, 2020

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Quoted 12 lines · Jason Gunthorpe
Quoted 11 lines · Andrew Morton
Quoted 8 lines · On Fri, 9 Oct 2020 17:03:37 +0200 "Christian König"…

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.

Quoted 6 lines
Quoted 2 lines

Doesn't this patch series address the same thing as
https://lkml.kernel.org/r/[email protected]?

Same basic issue, looks like both of these patches should be combined to plug it fully.

Jason

I think so too. Both of these patches fix the fput at possible wrong @file due to ->mmap() callback can change vma->vm_file.