The patch titled
Subject: mm/mmap: qvoid dereferencing next on null in BUG_ON()
has been added to the -mm mm-unstable branch. Its filename is
mm-mmap-use-advanced-maple-tree-api-for-mmap_region-fix-2.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mmap-use-advanced-maple-tree-api-for-mmap_region-fix-2.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: mm/mmap: qvoid dereferencing next on null in BUG_ON()
Date: Thu, 19 May 2022 15:04:50 +0000
Check there is a next before checking the bounds.
Link: https://lkml.kernel.org/r/20220519150442.1289962-1-Liam.Howlett@xxxxxxxxxx
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Reported-by: <syzbot+ee1fdd8dcc770a3a169a@xxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/mmap.c~mm-mmap-use-advanced-maple-tree-api-for-mmap_region-fix-2
+++ a/mm/mmap.c
@@ -685,7 +685,7 @@ inline int vma_expand(struct ma_state *m
}
/* Not merging but overwriting any part of next is not handled. */
- VM_BUG_ON(!remove_next && next != vma && end > next->vm_start);
+ VM_BUG_ON(next && !remove_next && next != vma && end > next->vm_start);
/* Only handles expanding */
VM_BUG_ON(vma->vm_start < start || vma->vm_end > end);
_
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
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
