[PATCH 4.14 153/167] scsi: core: check for device state in __scsi_remove_target()

Greg Kroah-Hartman
2018-02-21T13:04:46Z

From: Hannes Reinecke <hare@suse.de>

commit 81b6c999897919d5a16fedc018fe375dbab091c5 upstream.

As it turned out device_get() doesn't use kref_get_unless_zero(), so we
will be always getting a device pointer. Consequently, we need to check
for the device state in __scsi_remove_target() to avoid tripping over
deleted objects.

Fixes: fbce4d97fd43 ("scsi: fixup kernel warning during rmmod()")
Reported-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Max Ivanov <ivanov.maxim@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/scsi/scsi_sysfs.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1383,7 +1383,10 @@ static void __scsi_remove_target(struct
* check.
*/
if (sdev->channel != starget->channel ||
- sdev->id != starget->id ||
+ sdev->id != starget->id)
+ continue;
+ if (sdev->sdev_state == SDEV_DEL ||
+ sdev->sdev_state == SDEV_CANCEL ||
!get_device(&sdev->sdev_gendev))
continue;
spin_unlock_irqrestore(shost->host_lock, flags);