linux-kernel - [PATCH 4.19 191/313] drbd: disconnect, if the wrong UUIDs are attached on a connected peer

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: <20190211141906.022545214@linuxfoundation.org>
Date:   Mon, 11 Feb 2019 15:17:51 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Lars Ellenberg <lars.ellenberg@...bit.com>,
        Jens Axboe <axboe@...nel.dk>, Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.19 191/313] drbd: disconnect, if the wrong UUIDs are attached on a connected peer

4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

[ Upstream commit b17b59602b6dcf8f97a7dc7bc489a48388d7063a ]

With "on-no-data-accessible suspend-io", DRBD requires the next attach
or connect to be to the very same data generation uuid tag it lost last.

If we first lost connection to the peer,
then later lost connection to our own disk,
we would usually refuse to re-connect to the peer,
because it presents the wrong data set.

However, if the peer first connects without a disk,
and then attached its disk, we accepted that same wrong data set,
which would be "unexpected" by any user of that DRBD
and cause "undefined results" (read: very likely data corruption).

The fix is to forcefully disconnect as soon as we notice that the peer
attached to the "wrong" dataset.

Signed-off-by: Lars Ellenberg <lars.ellenberg@...bit.com>
Signed-off-by: Jens Axboe <axboe@...nel.dk>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/block/drbd/drbd_receiver.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 45ac5fe288e4..cb919b964066 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -4142,7 +4142,7 @@ static int receive_uuids(struct drbd_connection *connection, struct packet_info
 	kfree(device->p_uuid);
 	device->p_uuid = p_uuid;

-	if (device->state.conn < C_CONNECTED &&
+	if ((device->state.conn < C_CONNECTED || device->state.pdsk == D_DISKLESS) &&
 	    device->state.disk < D_INCONSISTENT &&
 	    device->state.role == R_PRIMARY &&
 	    (device->ed_uuid & ~((u64)1)) != (p_uuid[UI_CURRENT] & ~((u64)1))) {
-- 
2.19.1