nommu: Fix memory leak in do_mmap() error path

Commit Message

Liam R. Howlett Jan. 9, 2023, 8:55 p.m. UTC

The preallocation of the maple tree nodes may leak if the error path to
"error_just_free" is taken.  Fix this by moving the freeing of the maple
tree nodes to a shared location for all error paths.

Fixes: 8220543df148 ("nommu: remove uses of VMA linked list")
Signed-off-by: Liam R. Howlett <[e-mail]>
---
 mm/nommu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch

diff --git a/mm/nommu.c b/mm/nommu.c
index 214c70e1d059..c8252f01d5db 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1240,6 +1240,7 @@  unsigned long do_mmap(struct file *file,
 error_just_free:
 	up_write(&nommu_region_sem);
 error:
+	mas_destroy(&mas);
 	if (region->vm_file)
 		fput(region->vm_file);
 	kmem_cache_free(vm_region_jar, region);
@@ -1250,7 +1251,6 @@  unsigned long do_mmap(struct file *file,
 
 sharing_violation:
 	up_write(&nommu_region_sem);
-	mas_destroy(&mas);
 	pr_warn("Attempt to share mismatched mappings\n");
 	ret = -EINVAL;
 	goto error;