libubus: nullify stale msgbuf pointer in case of ubus_connect_ctx() failure

If the ubus_reconnect() call fails in ubus_connect_ctx(), the msgbuf.data
newly allocated buffer is freed, but its pointer in the ubus_context is not
removed.

This leads to a double free error if ubus_auto_shutdown() is called for cleanup
after ubus_auto_connect() failed to connect to ubusd.

Signed-off-by: Eyal Birger <eyal.birger@gmail.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/libubus.c b/libubus.c
index d52faff..8163ff7 100644
--- a/libubus.c
+++ b/libubus.c
@@ -294,6 +294,7 @@ int ubus_connect_ctx(struct ubus_context *ctx, const char *path)
 	avl_init(&ctx->objects, ubus_cmp_id, false, NULL);
 	if (ubus_reconnect(ctx, path)) {
 		free(ctx->msgbuf.data);
+		ctx->msgbuf.data = NULL;
 		return -1;
 	}