linux-kernel - [PATCH] module/decompress: Adjust module_extend_max

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <20250426062359.work.358-kees@kernel.org>
Date: Fri, 25 Apr 2025 23:24:00 -0700
From: Kees Cook <kees@...nel.org>
To: Luis Chamberlain <mcgrof@...nel.org>
Cc: Kees Cook <kees@...nel.org>,
	Petr Pavlu <petr.pavlu@...e.com>,
	Sami Tolvanen <samitolvanen@...gle.com>,
	Daniel Gomez <da.gomez@...sung.com>,
	linux-modules@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-hardening@...r.kernel.org
Subject: [PATCH] module/decompress: Adjust module_extend_max_pages() allocation type

In preparation for making the kmalloc family of allocators type aware,
we need to make sure that the returned type from the allocation matches
the type of the variable being assigned. (Before, the allocator would
always return "void *", which can be implicitly cast to any pointer type.)

The assigned type is "struct page **" but the returned type will be
"struct page ***". These have the same allocation size (pointer size), but
the types don't match. Adjust the allocation type to match the assignment.

Signed-off-by: Kees Cook <kees@...nel.org>
---
Cc: Luis Chamberlain <mcgrof@...nel.org>
Cc: Petr Pavlu <petr.pavlu@...e.com>
Cc: Sami Tolvanen <samitolvanen@...gle.com>
Cc: Daniel Gomez <da.gomez@...sung.com>
Cc: <linux-modules@...r.kernel.org>
---
 kernel/module/decompress.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/module/decompress.c b/kernel/module/decompress.c
index 474e68f0f063..bbb2a55568cd 100644
--- a/kernel/module/decompress.c
+++ b/kernel/module/decompress.c
@@ -19,7 +19,7 @@ static int module_extend_max_pages(struct load_info *info, unsigned int extent)
 	struct page **new_pages;
 
 	new_pages = kvmalloc_array(info->max_pages + extent,
-				   sizeof(info->pages), GFP_KERNEL);
+				   sizeof(*new_pages), GFP_KERNEL);
 	if (!new_pages)
 		return -ENOMEM;
 
-- 
2.34.1