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 <sagig@mellanox.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Slava Shwartsman <valyushash@gmail.com>
Cc: <stable@vger.kernel.org> # v3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Nicholas Bellinger 2015-02-23 00:57:51 -08:00
parent 2a03ee8c56
commit f068fbc82e

View File

@ -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);