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mm/mmap: undo ->mmap() when mas_preallocate() fails

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A memory leak in hugetlb_reserve_pages was reported in [1].  The root
cause was traced to an error path in mmap_region when mas_preallocate()
fails.  In this case, the vma is freed after a successful call to
filesystem specific mmap.  The hugetlbfs mmap routine may allocate data
structures pointed to by m_private_data.  These need to be cleaned up by
the hugetlb vm_ops->close() routine.

The same issue was addressed by commit deb0f65628 ("mm/mmap: undo
->mmap() when arch_validate_flags() fails") for the arch_validate_flags()
test.  Go to the same close_and_free_vma label if mas_preallocate() fails.

[1] https://lore.kernel.org/linux-mm/CAKXUXMxf7OiCwbxib7MwfR4M1b5+b3cNTU7n5NV9Zm4967=FPQ@mail.gmail.com/

Link: https://lkml.kernel.org/r/20221018024945.415036-1-mike.kravetz@oracle.com
Fixes: d4af56c5c7 ("mm: start tracking VMAs with maple tree")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Carlos Llamas <cmllamas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Mike Kravetz 2022-10-17 19:49:45 -07:00 committed by Andrew Morton
parent eacf96d23f
commit 5789151e48
1 changed files with 1 additions and 1 deletions
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2
mm/mmap.c
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@ -2681,7 +2681,7 @@ cannot_expand:
if (mas_preallocate(&mas, vma, GFP_KERNEL)) { if (mas_preallocate(&mas, vma, GFP_KERNEL)) {
error = -ENOMEM; error = -ENOMEM;
if (file) if (file)
goto unmap_and_free_vma; goto close_and_free_vma;
else else
goto free_vma; goto free_vma;
} }