[PATCH 5.4 79/84] scsi: core: Fix error handling of scsi_host_alloc()

Greg Kroah-Hartman
2021-06-14T11:03:15Z

From: Ming Lei <ming.lei@redhat.com>

commit 66a834d092930cf41d809c0e989b13cd6f9ca006 upstream.

After device is initialized via device_initialize(), or its name is set via
dev_set_name(), the device has to be freed via put_device(). Otherwise
device name will be leaked because it is allocated dynamically in
dev_set_name().

Fix the leak by replacing kfree() with put_device(). Since
scsi_host_dev_release() properly handles IDA and kthread removal, remove
special-casing these from the error handling as well.

Link: https://lore.kernel.org/r/20210602133029.2864069-2-ming.lei@redhat.com
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: John Garry <john.garry@huawei.com>
Cc: Hannes Reinecke <hare@suse.de>
Tested-by: John Garry <john.garry@huawei.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: John Garry <john.garry@huawei.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/scsi/hosts.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)

--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -389,8 +389,10 @@ struct Scsi_Host *scsi_host_alloc(struct
mutex_init(&shost->scan_mutex);

index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL);
- if (index < 0)
- goto fail_kfree;
+ if (index < 0) {
+ kfree(shost);
+ return NULL;
+ }
shost->host_no = index;

shost->dma_channel = 0xff;
@@ -482,7 +484,7 @@ struct Scsi_Host *scsi_host_alloc(struct
shost_printk(KERN_WARNING, shost,
"error handler thread failed to spawn, error = %ld\n",
PTR_ERR(shost->ehandler));
- goto fail_index_remove;
+ goto fail;
}

shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d",
@@ -491,17 +493,18 @@ struct Scsi_Host *scsi_host_alloc(struct
if (!shost->tmf_work_q) {
shost_printk(KERN_WARNING, shost,
"failed to create tmf workq\n");
- goto fail_kthread;
+ goto fail;
}
scsi_proc_hostdir_add(shost->hostt);
return shost;
+ fail:
+ /*
+ * Host state is still SHOST_CREATED and that is enough to release
+ * ->shost_gendev. scsi_host_dev_release() will free
+ * dev_name(&shost->shost_dev).
+ */
+ put_device(&shost->shost_gendev);

- fail_kthread:
- kthread_stop(shost->ehandler);
- fail_index_remove:
- ida_simple_remove(&host_index_ida, shost->host_no);
- fail_kfree:
- kfree(shost);
return NULL;
}
EXPORT_SYMBOL(scsi_host_alloc);