vhost: fix crash on vhost-user client port deletion
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Commit Message
The rte_vhost_driver_unregister() and vhost_user_read_cb() can be
called at the same time by 2 threads. reconn may be added back to
reconn_list by vhost_user_read_cb() after rte_vhost_driver_unregister()
removed from reconn_list. Then rte_vhost_driver_unregister free vsocket,
cause vhost_user_client_reconnect access invalid vsocket memory.
Timeline is as below:
rte_vhost_driver_unregister thread excute vhost_user_remove_reconnect
vhost_user_read_cb thread excute vhost_user_start_client add reconn to reconn_list
vhost_user_read_cb thread free conn
rte_vhost_driver_unregister thread cannot find conn, then excute vhost_user_socket_mem_free
vhost_user_client_reconnect access invalid mem, crash
Signed-off-by: suntianyuan <suntianyuan@baidu.com>
---
lib/vhost/socket.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
Comments
Hi Tianyuan,
> -----Original Message-----
> From: suntianyuan <suntianyuan@baidu.com>
> Sent: Tuesday, March 21, 2023 2:24 PM
> To: maxime.coquelin@redhat.com; Xia, Chenbo <chenbo.xia@intel.com>
> Cc: dev@dpdk.org; suntianyuan <suntianyuan@baidu.com>
> Subject: [PATCH] vhost: fix crash on vhost-user client port deletion
>
> The rte_vhost_driver_unregister() and vhost_user_read_cb() can be
> called at the same time by 2 threads. reconn may be added back to
> reconn_list by vhost_user_read_cb() after rte_vhost_driver_unregister()
> removed from reconn_list. Then rte_vhost_driver_unregister free vsocket,
> cause vhost_user_client_reconnect access invalid vsocket memory.
>
> Timeline is as below:
> rte_vhost_driver_unregister thread excute vhost_user_remove_reconnect
> vhost_user_read_cb thread excute vhost_user_start_client add reconn to
> reconn_list
> vhost_user_read_cb thread free conn
> rte_vhost_driver_unregister thread cannot find conn, then excute
> vhost_user_socket_mem_free
> vhost_user_client_reconnect access invalid mem, crash
>
> Signed-off-by: suntianyuan <suntianyuan@baidu.com>
There are several coding style issues. Please check and fix:
http://mails.dpdk.org/archives/test-report/2023-March/374602.html
Thanks,
Chenbo
> ---
> lib/vhost/socket.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/lib/vhost/socket.c b/lib/vhost/socket.c
> index 669c322e12..72c776d15c 100644
> --- a/lib/vhost/socket.c
> +++ b/lib/vhost/socket.c
> @@ -1046,8 +1046,6 @@ rte_vhost_driver_unregister(const char *path)
> pthread_mutex_unlock(&vhost_user.mutex);
> goto again;
> }
> - } else if (vsocket->reconnect) {
> - vhost_user_remove_reconnect(vsocket);
> }
>
> pthread_mutex_lock(&vsocket->conn_mutex);
> @@ -1080,6 +1078,8 @@ rte_vhost_driver_unregister(const char *path)
> if (vsocket->is_server) {
> close(vsocket->socket_fd);
> unlink(path);
> + } else if (vsocket->reconnect) {
> + vhost_user_remove_reconnect(vsocket);
> }
>
> pthread_mutex_destroy(&vsocket->conn_mutex);
> --
> 2.32.0 (Apple Git-132)
@@ -1046,8 +1046,6 @@ rte_vhost_driver_unregister(const char *path)
pthread_mutex_unlock(&vhost_user.mutex);
goto again;
}
- } else if (vsocket->reconnect) {
- vhost_user_remove_reconnect(vsocket);
}
pthread_mutex_lock(&vsocket->conn_mutex);
@@ -1080,6 +1078,8 @@ rte_vhost_driver_unregister(const char *path)
if (vsocket->is_server) {
close(vsocket->socket_fd);
unlink(path);
+ } else if (vsocket->reconnect) {
+ vhost_user_remove_reconnect(vsocket);
}
pthread_mutex_destroy(&vsocket->conn_mutex);