From: Liam Howlett <liam.howlett@oracle.com>
Date: Mon, 9 Jan 2023 20:55:21 +0000 (+0000)
Subject: nommu: fix memory leak in do_mmap() error path
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=7f31cced5724e6d414fe750aa1cd7e7b578ec22f;p=linux.git

nommu: fix memory leak in do_mmap() error path

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.

Link: https://lkml.kernel.org/r/20230109205507.955577-1-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>
---

diff --git a/mm/nommu.c b/mm/nommu.c
index 214c70e1d0594..c8252f01d5dbb 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1240,6 +1240,7 @@ share:
 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 @@ error:
 
 sharing_violation:
 	up_write(&nommu_region_sem);
-	mas_destroy(&mas);
 	pr_warn("Attempt to share mismatched mappings\n");
 	ret = -EINVAL;
 	goto error;