From a67417ab7eeff45bba55666c0e1083260f3624ee Mon Sep 17 00:00:00 2001 From: Swen Schillig Date: Tue, 18 Aug 2009 15:43:06 +0200 Subject: [PATCH] [SCSI] zfcp: invalid usage after free of port resources In certain error scenarios ports, rports are getting attached, validated and removed from the systems environment. Depending on the layer this occurs asynchronously. This patch fixes the few races which existed and ensures all references and cross references are cleared at the time they're invalid. In addition fc transports actions are only scheduled when required. Signed-off-by: Swen Schillig Signed-off-by: Christof Schmitt Signed-off-by: James Bottomley --- drivers/s390/scsi/zfcp_aux.c | 7 +++++-- drivers/s390/scsi/zfcp_scsi.c | 6 ++++-- 2 files changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c index 2ccbd185a5f..fa2460b4229 100644 --- a/drivers/s390/scsi/zfcp_aux.c +++ b/drivers/s390/scsi/zfcp_aux.c @@ -672,12 +672,15 @@ err_out: */ void zfcp_port_dequeue(struct zfcp_port *port) { - wait_event(port->remove_wq, atomic_read(&port->refcount) == 0); write_lock_irq(&zfcp_data.config_lock); list_del(&port->list); write_unlock_irq(&zfcp_data.config_lock); - if (port->rport) + if (port->rport) { port->rport->dd_data = NULL; + port->rport = NULL; + } + wait_event(port->remove_wq, atomic_read(&port->refcount) == 0); + cancel_work_sync(&port->rport_work); /* usually not necessary */ zfcp_adapter_put(port->adapter); sysfs_remove_group(&port->sysfs_device.kobj, &zfcp_sysfs_port_attrs); device_unregister(&port->sysfs_device); diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c index 6925a178468..54a7a7474aa 100644 --- a/drivers/s390/scsi/zfcp_scsi.c +++ b/drivers/s390/scsi/zfcp_scsi.c @@ -582,8 +582,10 @@ void zfcp_scsi_schedule_rport_block(struct zfcp_port *port) zfcp_port_get(port); port->rport_task = RPORT_DEL; - if (!queue_work(zfcp_data.work_queue, &port->rport_work)) - zfcp_port_put(port); + if (port->rport && queue_work(zfcp_data.work_queue, &port->rport_work)) + return; + + zfcp_port_put(port); } void zfcp_scsi_schedule_rports_block(struct zfcp_adapter *adapter)