The patch titled
Subject: fs/userfaultfd: fix vma iteration in mas_for_each() loop
has been added to the -mm mm-unstable branch. Its filename is
userfaultfd-use-maple-tree-iterator-to-iterate-vmas-fix.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/userfaultfd-use-maple-tree-iterator-to-iterate-vmas-fix.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Liam Howlett <liam.howlett@xxxxxxxxxx>
Subject: fs/userfaultfd: fix vma iteration in mas_for_each() loop
Date: Wed, 15 Jun 2022 16:42:17 +0000
The maple tree state becomes stale when the tree is altered and requires
the iteration to be paused with mas_pause(). This forces the next
iteration to start from the top of tree for the next entry.
Link: https://lkml.kernel.org/r/20220615164150.652376-1-Liam.Howlett@xxxxxxxxxx
Fixes: "userfaultfd-use-maple-tree-iterator-to-iterate-vmas.patch"
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Reported-by: syzbot+68771c0e74f7bb7804e5@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/userfaultfd.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/fs/userfaultfd.c~userfaultfd-use-maple-tree-iterator-to-iterate-vmas-fix
+++ a/fs/userfaultfd.c
@@ -890,10 +890,13 @@ static int userfaultfd_release(struct in
vma->vm_file, vma->vm_pgoff,
vma_policy(vma),
NULL_VM_UFFD_CTX, anon_vma_name(vma));
- if (prev)
+ if (prev) {
+ mas_pause(&mas);
vma = prev;
- else
+ } else {
prev = vma;
+ }
+
vma->vm_flags = new_flags;
vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;
}
_
Patches currently in -mm which might be from liam.howlett@xxxxxxxxxx are
maple-tree-add-new-data-structure-fix.patch
maple-tree-add-new-data-structure-fix-2.patch
maple-tree-add-new-data-structure-fix-3.patch
maple-tree-add-new-data-structure-fix-4.patch
maple-tree-add-new-data-structure-fix-7.patch
maple-tree-add-new-data-structure-fix-8.patch
maple-tree-add-new-data-structure-fix-8-fix.patch
maple-tree-add-new-data-structure-fix-9.patch
maple-tree-add-new-data-structure-fix-10.patch
lib-test_maple_tree-add-testing-for-maple-tree-fix.patch
lib-test_maple_tree-add-testing-for-maple-tree-fix-2.patch
mm-start-tracking-vmas-with-maple-tree-fix-2.patch
mm-mmap-use-advanced-maple-tree-api-for-mmap_region-fix-2.patch
mm-mmap-use-advanced-maple-tree-api-for-mmap_region-fix-3.patch
mm-mmap-change-do_brk_munmap-to-use-do_mas_align_munmap-fix.patch
userfaultfd-use-maple-tree-iterator-to-iterate-vmas-fix.patch
mm-remove-the-vma-linked-list-fix.patch
mm-remove-the-vma-linked-list-fix-4.patch
mm-mlock-drop-dead-code-in-count_mm_mlocked_page_nr.patch
