linux-kernel - [PATCH] fs/proc/task_mmu: prevent integer overflow in pagemap_scan_get

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>] [thread-next>] [day] [month] [year] [list]

Message-ID: <39d41335-dd4d-48ed-8a7f-402c57d8ea84@stanley.mountain>
Date: Thu, 14 Nov 2024 11:59:32 +0300
From: Dan Carpenter <dan.carpenter@...aro.org>
To: Muhammad Usama Anjum <usama.anjum@...labora.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
	David Hildenbrand <david@...hat.com>,
	Matthew Wilcox <willy@...radead.org>,
	Oscar Salvador <osalvador@...e.de>,
	Andrii Nakryiko <andrii@...nel.org>,
	Ryan Roberts <ryan.roberts@....com>, Peter Xu <peterx@...hat.com>,
	Michał Mirosław <mirq-linux@...e.qmqm.pl>,
	Andrei Vagin <avagin@...gle.com>, Arnd Bergmann <arnd@...db.de>,
	linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org,
	kernel-janitors@...r.kernel.org
Subject: [PATCH] fs/proc/task_mmu: prevent integer overflow in
 pagemap_scan_get_args()

The "arg->vec_len" variable is a u64 that comes from the user at the
start of the function.  The "arg->vec_len * sizeof(struct page_region))"
multiplication can lead to integer wrapping.  Use size_mul() to avoid
that.

Also the size_add/mul() functions work on unsigned long so for 32bit
systems we need to ensure that "arg->vec_len" fits in an unsigned long.

Fixes: 52526ca7fdb9 ("fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs")
Cc: stable@...r.kernel.org
Signed-off-by: Dan Carpenter <dan.carpenter@...aro.org>
---
 fs/proc/task_mmu.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index f57ea9b308bb..38a5a3e9cba2 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -2665,8 +2665,10 @@ static int pagemap_scan_get_args(struct pm_scan_arg *arg,
 		return -EFAULT;
 	if (!arg->vec && arg->vec_len)
 		return -EINVAL;
+	if (UINT_MAX == SIZE_MAX && arg->vec_len > SIZE_MAX)
+		return -EINVAL;
 	if (arg->vec && !access_ok((void __user *)(long)arg->vec,
-			      arg->vec_len * sizeof(struct page_region)))
+				   size_mul(arg->vec_len, sizeof(struct page_region))))
 		return -EFAULT;
 
 	/* Fixup default values */
-- 
2.45.2