From: Mikulas Patocka <mpatocka@redhat.com>
Date: Thu, 9 Jul 2026 19:31:47 +0000 (+0200)
Subject: dm-ioctl: fix a possible overflow in list_version_get_info
X-Git-Tag: v7.2-rc3~11^2~8
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=76c6f845dc0c614304a6e6ee619b552f97cf24b3;p=thirdparty%2Fkernel%2Flinux.git

dm-ioctl: fix a possible overflow in list_version_get_info

sizeof(tt->version) is 12 bytes, but the code writes 16 bytes into the
output buffer - info->vers->version[0], info->vers->version[1],
info->vers->version[2] and info->vers->next. This can cause buffer
overflow.

Fix this buffer overflow by replacing "sizeof(tt->version)" with
"sizeof(struct dm_target_versions)".

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Assisted-by: Claude:claude-opus-4.6
Cc: stable@vger.kernel.org
---

diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 1fa8bf835be0..61af2a437a05 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -785,7 +785,7 @@ static void list_version_get_info(struct target_type *tt, void *param)
 	struct vers_iter *info = param;
 
 	/* Check space - it might have changed since the first iteration */
-	if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 > info->end) {
+	if ((char *)info->vers + sizeof(struct dm_target_versions) + strlen(tt->name) + 1 > info->end) {
 		info->flags = DM_BUFFER_FULL_FLAG;
 		return;
 	}