+ mm-mmap-change-do_brk_munmap-to-use-do_mas_align_munmap-fix.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm/mmap: fix do_brk_munmap() when munmapping multiple mappings
has been added to the -mm mm-unstable branch.  Its filename is
     mm-mmap-change-do_brk_munmap-to-use-do_mas_align_munmap-fix.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mmap-change-do_brk_munmap-to-use-do_mas_align_munmap-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@oracle.com>
Subject: mm/mmap: fix do_brk_munmap() when munmapping multiple mappings
Date: Thu, 19 May 2022 15:05:22 +0000

If the newbrk is less than the last brk vma start, then munmap entire
VMA(s).

Link: https://lkml.kernel.org/r/20220519150509.1290067-1-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/mmap.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/mm/mmap.c~mm-mmap-change-do_brk_munmap-to-use-do_mas_align_munmap-fix
+++ a/mm/mmap.c
@@ -3056,8 +3056,7 @@ static int do_brk_munmap(struct ma_state
 
 	arch_unmap(mm, newbrk, oldbrk);
 
-	if (likely((vma->vm_end < oldbrk) ||
-		   ((vma->vm_start == newbrk) && (vma->vm_end == oldbrk)))) {
+	if (likely((vma->vm_end < oldbrk) || (vma->vm_start >= newbrk))) {
 		/* remove entire mapping(s) */
 		ret = do_mas_align_munmap(mas, vma, mm, newbrk, oldbrk, uf,
 					  true);
_

Patches currently in -mm which might be from liam.howlett@oracle.com 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
lib-test_maple_tree-add-testing-for-maple-tree-fix.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-change-do_brk_munmap-to-use-do_mas_align_munmap-fix.patch
mm-remove-the-vma-linked-list-fix.patch