From 6eaf69e4ec075f5af236c0c89f75639a195db904 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Tue, 31 Oct 2017 11:03:18 -0700 Subject: [PATCH] target/iscsi: Detect conn_cmd_list corruption early Certain behavior of the initiator can cause the target driver to send both a reject and a SCSI response. If that happens two target_put_sess_cmd() calls will occur without the command having been removed from conn_cmd_list. In other words, conn_cmd_list will get corrupted once the freed memory is reused. Although the Linux kernel can detect list corruption if list debugging is enabled, in this case the context in which list corruption is detected is not related to the context that caused list corruption. Hence add WARN_ON() statements that report the context that is causing list corruption. Signed-off-by: Bart Van Assche Cc: Christoph Hellwig Cc: Mike Christie Reviewed-by: Hannes Reinecke Signed-off-by: Nicholas Bellinger --- drivers/target/iscsi/iscsi_target_util.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c index 1e36f83b5961..70c6b9bfc04e 100644 --- a/drivers/target/iscsi/iscsi_target_util.c +++ b/drivers/target/iscsi/iscsi_target_util.c @@ -694,6 +694,8 @@ void iscsit_release_cmd(struct iscsi_cmd *cmd) struct iscsi_session *sess; struct se_cmd *se_cmd = &cmd->se_cmd; + WARN_ON(!list_empty(&cmd->i_conn_node)); + if (cmd->conn) sess = cmd->conn->sess; else @@ -716,6 +718,8 @@ void __iscsit_free_cmd(struct iscsi_cmd *cmd, bool check_queues) { struct iscsi_conn *conn = cmd->conn; + WARN_ON(!list_empty(&cmd->i_conn_node)); + if (cmd->data_direction == DMA_TO_DEVICE) { iscsit_stop_dataout_timer(cmd); iscsit_free_r2ts_from_list(cmd); -- 2.30.2