From 8b36aa5af4daf239937bfb5a3592cfea4f601668 Mon Sep 17 00:00:00 2001 From: Lixiaokeng Date: Mon, 20 Dec 2021 19:39:06 +0800 Subject: [PATCH] scsi: libiscsi: Fix UAF in iscsi_conn_get_param()/iscsi_conn_teardown() [ Upstream commit 1b8d0300a3e9f216ae4901bab886db7299899ec6 ] |- iscsi_if_destroy_conn |-dev_attr_show |-iscsi_conn_teardown |-spin_lock_bh |-iscsi_sw_tcp_conn_get_param |-kfree(conn->persistent_address) |-iscsi_conn_get_param |-kfree(conn->local_ipaddr) ==>|-read persistent_address ==>|-read local_ipaddr |-spin_unlock_bh When iscsi_conn_teardown() and iscsi_conn_get_param() happen in parallel, a UAF may be triggered. Link: https://lore.kernel.org/r/046ec8a0-ce95-d3fc-3235-666a7c65b224@huawei.com Reported-by: Lu Tixiong Reviewed-by: Mike Christie Reviewed-by: Lee Duncan Signed-off-by: Lixiaokeng Signed-off-by: Linfeilong Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/libiscsi.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index eeba6180711c..f3cee64c6d12 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -2948,6 +2948,8 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn) { struct iscsi_conn *conn = cls_conn->dd_data; struct iscsi_session *session = conn->session; + char *tmp_persistent_address = conn->persistent_address; + char *tmp_local_ipaddr = conn->local_ipaddr; del_timer_sync(&conn->transport_timer); @@ -2969,8 +2971,6 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn) spin_lock_bh(&session->frwd_lock); free_pages((unsigned long) conn->data, get_order(ISCSI_DEF_MAX_RECV_SEG_LEN)); - kfree(conn->persistent_address); - kfree(conn->local_ipaddr); /* regular RX path uses back_lock */ spin_lock_bh(&session->back_lock); kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task, @@ -2982,6 +2982,8 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn) mutex_unlock(&session->eh_mutex); iscsi_destroy_conn(cls_conn); + kfree(tmp_persistent_address); + kfree(tmp_local_ipaddr); } EXPORT_SYMBOL_GPL(iscsi_conn_teardown);