From: Lixiaokeng <lixiaokeng@huawei.com> stable inclusion from linux-4.19.225 commit f5596fdc65ce280cb4debb507c0c5877d1a89936 -------------------------------- [ 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 <lutianxiong@huawei.com> Reviewed-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Lee Duncan <lduncan@suse.com> Signed-off-by: Lixiaokeng <lixiaokeng@huawei.com> Signed-off-by: Linfeilong <linfeilong@huawei.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> Signed-off-by: Laibin Qiu <qiulaibin@huawei.com> --- 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 02060aec08bf..a93a47d4931f 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -3133,6 +3133,8 @@ 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); @@ -3156,8 +3158,6 @@ 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, @@ -3169,6 +3169,8 @@ 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); -- 2.22.0