From f068fbc82e7696d67b1bb8189306865bedf368b6 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Mon, 23 Feb 2015 00:57:51 -0800 Subject: [PATCH] iscsi-target: Avoid early conn_logout_comp for iser connections This patch fixes a iser specific logout bug where early complete() of conn->conn_logout_comp in iscsit_close_connection() was causing isert_wait4logout() to complete too soon, triggering a use after free NULL pointer dereference of iscsi_conn memory. The complete() was originally added for traditional iscsi-target when a ISCSI_LOGOUT_OP failed in iscsi_target_rx_opcode(), but given iser-target does not wait in logout failure, this special case needs to be avoided. Reported-by: Sagi Grimberg Cc: Sagi Grimberg Cc: Slava Shwartsman Cc: # v3.10+ Signed-off-by: Nicholas Bellinger --- drivers/target/iscsi/iscsi_target.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c index 50bad55a0c42..2accb6e47beb 100644 --- a/drivers/target/iscsi/iscsi_target.c +++ b/drivers/target/iscsi/iscsi_target.c @@ -4256,11 +4256,17 @@ int iscsit_close_connection( pr_debug("Closing iSCSI connection CID %hu on SID:" " %u\n", conn->cid, sess->sid); /* - * Always up conn_logout_comp just in case the RX Thread is sleeping - * and the logout response never got sent because the connection - * failed. + * Always up conn_logout_comp for the traditional TCP case just in case + * the RX Thread in iscsi_target_rx_opcode() is sleeping and the logout + * response never got sent because the connection failed. + * + * However for iser-target, isert_wait4logout() is using conn_logout_comp + * to signal logout response TX interrupt completion. Go ahead and skip + * this for iser since isert_rx_opcode() does not wait on logout failure, + * and to avoid iscsi_conn pointer dereference in iser-target code. */ - complete(&conn->conn_logout_comp); + if (conn->conn_transport->transport_type == ISCSI_TCP) + complete(&conn->conn_logout_comp); iscsi_release_thread_set(conn); -- 2.39.2