From 5789151e48acc3fd34d2109bf2021dc4df5e33e9 Mon Sep 17 00:00:00 2001
From: Mike Kravetz <mike.kravetz@oracle.com>
Date: Mon, 17 Oct 2022 19:49:45 -0700
Subject: [PATCH] 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 deb0f6562884 ("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: d4af56c5c7c6 ("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>
---
mm/mmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
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 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
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;
}
--
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