From e5b815b0defcc3617f473ba70c3e675ef0ee69c2 Mon Sep 17 00:00:00 2001
From: "Denis V. Lunev" <den@openvz.org>
Date: Thu, 27 Jul 2023 12:58:28 +0200
Subject: [PATCH] qemu-nbd: regression with arguments passing into
nbd_client_thread()
Unfortunately
commit 03b67621445d601c9cdc7dfe25812e9f19b81488
Author: Denis V. Lunev <den@openvz.org>
Date: Mon Jul 17 16:55:40 2023 +0200
qemu-nbd: pass structure into nbd_client_thread instead of plain char*
has introduced a regression. struct NbdClientOpts resides on stack inside
'if' block. This specifically means that this stack space could be reused
once the execution will leave that block of the code.
This means that parameters passed into nbd_client_thread could be
overwritten at any moment.
The patch moves the data to the namespace of main() function effectively
preserving it for the whole process lifetime.
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Eric Blake <eblake@redhat.com>
CC: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
CC: <qemu-stable@nongnu.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-ID: <20230727105828.324314-1-den@openvz.org>
Signed-off-by: Eric Blake <eblake@redhat.com>
---
qemu-nbd.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/qemu-nbd.c b/qemu-nbd.c
index 5b2757920c1..aaccaa33184 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -589,6 +589,9 @@ int main(int argc, char **argv)
const char *pid_file_name = NULL;
const char *selinux_label = NULL;
BlockExportOptions *export_opts;
+#if HAVE_NBD_DEVICE
+ struct NbdClientOpts opts;
+#endif
#ifdef CONFIG_POSIX
os_setup_early_signal_handling();
@@ -1145,7 +1148,7 @@ int main(int argc, char **argv)
if (device) {
#if HAVE_NBD_DEVICE
int ret;
- struct NbdClientOpts opts = {
+ opts = (struct NbdClientOpts) {
.device = device,
.fork_process = fork_process,
.verbose = verbose,
--
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