From: Mike Kravetz <mike.kravetz@oracle.com>
Date: Tue, 18 Oct 2022 02:49:45 +0000 (-0700)
Subject: mm/mmap: undo ->mmap() when mas_preallocate() fails
X-Git-Tag: baikal/aarch64/sdk6.1~2798^2~8
X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=8c37e6862a5205f7ac383a5e8a1670b2326b5f0f;p=kernel.git

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

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 e8e2cf37762d ("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: 8fba796e9cfc ("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>
---

diff --git a/mm/mmap.c b/mm/mmap.c
index bf2122af94e7a..3c9890e443a3e 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2681,7 +2681,7 @@ cannot_expand:
 	if (mas_preallocate(&mas, vma, GFP_KERNEL)) {
 		error = -ENOMEM;
 		if (file)
-			goto unmap_and_free_vma;
+			goto close_and_free_vma;
 		else
 			goto free_vma;
 	}