linux-kernel - [PATCH AUTOSEL 5.4 22/79] dm: restrict dm device size to 2^63-512 bytes

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

Message-Id: <20250505232151.2698893-22-sashal@kernel.org>
Date: Mon,  5 May 2025 19:20:54 -0400
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Cc: Mikulas Patocka <mpatocka@...hat.com>,
	Sasha Levin <sashal@...nel.org>,
	agk@...hat.com,
	snitzer@...nel.org,
	dm-devel@...ts.linux.dev
Subject: [PATCH AUTOSEL 5.4 22/79] dm: restrict dm device size to 2^63-512 bytes

From: Mikulas Patocka <mpatocka@...hat.com>

[ Upstream commit 45fc728515c14f53f6205789de5bfd72a95af3b8 ]

The devices with size >= 2^63 bytes can't be used reliably by userspace
because the type off_t is a signed 64-bit integer.

Therefore, we limit the maximum size of a device mapper device to
2^63-512 bytes.

Signed-off-by: Mikulas Patocka <mpatocka@...hat.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/md/dm-table.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index fcb9e2775f78a..5b0d45d92e654 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -741,6 +741,10 @@ int dm_table_add_target(struct dm_table *t, const char *type,
 		DMERR("%s: zero-length target", dm_device_name(t->md));
 		return -EINVAL;
 	}
+	if (start + len < start || start + len > LLONG_MAX >> SECTOR_SHIFT) {
+		DMERR("%s: too large device", dm_device_name(t->md));
+		return -EINVAL;
+	}
 
 	tgt->type = dm_get_target_type(type);
 	if (!tgt->type) {
-- 
2.39.5