mm/mmap: Fix do_brk_munmap() when munmapping an entire VMA or more

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>

diff --git a/mm/mmap.c b/mm/mmap.c
index b50d8fed4da1e0d47bc0ca0edd2af7ce441de0eb..b4879e66f87de55b70265fc56df6127adbf2a313 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2927,7 +2927,10 @@ static int do_brk_munmap(struct ma_state *mas, struct vm_area_struct *vma,
 
        arch_unmap(mm, newbrk, oldbrk);
 
-       if (likely(vma->vm_start >= newbrk)) { // remove entire mapping(s)
+
+       if (likely((vma->vm_end < oldbrk) ||
+                  ((vma->vm_start == newbrk) && (vma->vm_end == oldbrk)))) {
+               // remove entire mapping(s)
                mas->last = oldbrk - 1;
                ret = do_mas_align_munmap(mas, vma, mm, newbrk, oldbrk, uf,
                                          true);