nbdkit/0001-server-reset-meta-context-replies-on-starttls.patch
Richard W.M. Jones a86e62e68a Rebase along stable branch to 1.26.5
resolves: rhbz#1995327
Add nbdkit-vddk-plugin -D vddk.stats=1 flag
resolves: rhbz#1995329
Add nbdkit-cow-filter cow-block-size parameter
resolves: rhbz#1995332
Fix CVE-2021-3716 nbdkit: NBD_OPT_STRUCTURED_REPLY injection on STARTTLS
Update keyring
2021-08-19 09:12:41 +01:00

40 lines
1.7 KiB
Diff

From 89ef17c90996c0e212e3a17c8d26ff930ab464ea Mon Sep 17 00:00:00 2001
From: Eric Blake <eblake@redhat.com>
Date: Mon, 16 Aug 2021 13:43:29 -0500
Subject: [PATCH] server: reset meta context replies on starttls
Related to CVE-2021-3716, but not as severe. No compliant client will
send NBD_CMD_BLOCK_STATUS unless it first negotiates
NBD_OPT_SET_META_CONTEXT. If an attacker injects a premature
SET_META_CONTEXT, either the client will never notice (because it
never uses BLOCK_STATUS), or the client will overwrite the attacker's
attempt with the client's own SET_META_CONTEXT request after
encryption is enabled. So I don't class this as having the potential
to trigger denial-of-service due to any protocol mismatch between
compliant client and server (I don't care what happens with
non-compliant clients).
Fixes: 26455d45 (server: protocol: Implement Block Status "base:allocation".)
(cherry picked from commit 6c5faac6a37077cf2366388a80862bb00616d0d8)
---
server/protocol-handshake-newstyle.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/server/protocol-handshake-newstyle.c b/server/protocol-handshake-newstyle.c
index 7e6b7b1b..79b2c8ce 100644
--- a/server/protocol-handshake-newstyle.c
+++ b/server/protocol-handshake-newstyle.c
@@ -497,6 +497,9 @@ negotiate_handshake_newstyle_options (void)
debug ("using TLS on this connection");
/* Wipe out any cached state. */
conn->structured_replies = false;
+ free (conn->exportname_from_set_meta_context);
+ conn->exportname_from_set_meta_context = NULL;
+ conn->meta_context_base_allocation = false;
for_each_backend (b) {
free (conn->default_exportname[b->i]);
conn->default_exportname[b->i] = NULL;
--
2.31.1