dm: restrict dm device size to 2^63-512 bytes

[ 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@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Mikulas Patocka
2025-03-14 13:51:32 +01:00
committed by Greg Kroah-Hartman
parent 44a82d2495
commit ba8354a613

View File

@@ -669,6 +669,10 @@ 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;
}
ti->type = dm_get_target_type(type);
if (!ti->type) {