nommu: fix do_munmap() error path

commit 80be727ec87225797771a39f3e6801baf291faaf upstream.

When removing a VMA from the tree fails due to no memory, do not free the
VMA since a reference still exists.

Link: https://lkml.kernel.org/r/20230109205708.956103-1-Liam.Howlett@oracle.com
Fixes: 8220543df148 ("nommu: remove uses of VMA linked list")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/mm/nommu.c b/mm/nommu.c
index c8252f0..844af5b 100644 (file)
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1509,7 +1509,8 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len, struct list
 erase_whole_vma:
        if (delete_vma_from_mm(vma))
                ret = -ENOMEM;
-       delete_vma(mm, vma);
+       else
+               delete_vma(mm, vma);
        return ret;
 }