1 files changed, 80 insertions, 0 deletions
diff --git a/app-emulation/qemu/files/qemu-2.9.0-CVE-2017-9524-1.patch b/app-emulation/qemu/files/qemu-2.9.0-CVE-2017-9524-1.patch
new file mode 100644
index 000000000000..9d77193b1f6a
--- /dev/null
+++ b/app-emulation/qemu/files/qemu-2.9.0-CVE-2017-9524-1.patch
@@ -0,0 +1,80 @@
+From df8ad9f128c15aa0a0ebc7b24e9a22c9775b67af Mon Sep 17 00:00:00 2001
+From: Eric Blake <eblake@redhat.com>
+Date: Fri, 26 May 2017 22:04:21 -0500
+Subject: [PATCH] nbd: Fully initialize client in case of failed negotiation
+
+If a non-NBD client connects to qemu-nbd, we would end up with
+a SIGSEGV in nbd_client_put() because we were trying to
+unregister the client's association to the export, even though
+we skipped inserting the client into that list.  Easy trigger
+in two terminals:
+
+$ qemu-nbd -p 30001 --format=raw file
+$ nmap 127.0.0.1 -p 30001
+
+nmap claims that it thinks it connected to a pago-services1
+server (which probably means nmap could be updated to learn the
+NBD protocol and give a more accurate diagnosis of the open
+port - but that's not our problem), then terminates immediately,
+so our call to nbd_negotiate() fails.  The fix is to reorder
+nbd_co_client_start() to ensure that all initialization occurs
+before we ever try talking to a client in nbd_negotiate(), so
+that the teardown sequence on negotiation failure doesn't fault
+while dereferencing a half-initialized object.
+
+While debugging this, I also noticed that nbd_update_server_watch()
+called by nbd_client_closed() was still adding a channel to accept
+the next client, even when the state was no longer RUNNING.  That
+is fixed by making nbd_can_accept() pay attention to the current
+state.
+
+Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1451614
+
+Signed-off-by: Eric Blake <eblake@redhat.com>
+Message-Id: <20170527030421.28366-1-eblake@redhat.com>
+Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
+---
+ nbd/server.c | 8 +++-----
+ qemu-nbd.c   | 2 +-
+ 2 files changed, 4 insertions(+), 6 deletions(-)
+
+diff --git a/nbd/server.c b/nbd/server.c
+index ee59e5d234..49b55f6ede 100644
+--- a/nbd/server.c
++++ b/nbd/server.c
+@@ -1358,16 +1358,14 @@ static coroutine_fn void nbd_co_client_start(void *opaque)
+ 
+     if (exp) {
+         nbd_export_get(exp);
++        QTAILQ_INSERT_TAIL(&exp->clients, client, next);
+     }
++    qemu_co_mutex_init(&client->send_lock);
++
+     if (nbd_negotiate(data)) {
+         client_close(client);
+         goto out;
+     }
+-    qemu_co_mutex_init(&client->send_lock);
+-
+-    if (exp) {
+-        QTAILQ_INSERT_TAIL(&exp->clients, client, next);
+-    }
+ 
+     nbd_client_receive_next_request(client);
+ 
+diff --git a/qemu-nbd.c b/qemu-nbd.c
+index f60842fd86..651f85ecc1 100644
+--- a/qemu-nbd.c
++++ b/qemu-nbd.c
+@@ -325,7 +325,7 @@ out:
+ 
+ static int nbd_can_accept(void)
+ {
+-    return nb_fds < shared;
++    return state == RUNNING && nb_fds < shared;
+ }
+ 
+ static void nbd_export_closed(NBDExport *exp)
+-- 
+2.13.0
+