scsi: iscsi: Fix iscsi_task use after free

Commit d39df15851 ("scsi: iscsi: Have abort handler get ref to conn")
added iscsi_get_conn()/iscsi_put_conn() calls during abort handling but
then also changed the handling of the case where we detect an already
completed task where we now end up doing a goto to the common put/cleanup
code. This results in a iscsi_task use after free, because the common
cleanup code will do a put on the iscsi_task.

This reverts the goto and moves the iscsi_get_conn() to after we've checked
if the iscsi_task is valid.

Link: https://lore.kernel.org/r/20211004210608.9962-1-michael.christie@oracle.com
Fixes: d39df15851 ("scsi: iscsi: Have abort handler get ref to conn")
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Mike Christie 2021-10-04 16:06:08 -05:00 committed by Martin K. Petersen
parent 69a3a7bc72
commit 258aad75c6

View File

@ -2281,11 +2281,6 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
return FAILED;
}
conn = session->leadconn;
iscsi_get_conn(conn->cls_conn);
conn->eh_abort_cnt++;
age = session->age;
spin_lock(&session->back_lock);
task = (struct iscsi_task *)sc->SCp.ptr;
if (!task || !task->sc) {
@ -2293,8 +2288,16 @@ int iscsi_eh_abort(struct scsi_cmnd *sc)
ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
spin_unlock(&session->back_lock);
goto success;
spin_unlock_bh(&session->frwd_lock);
mutex_unlock(&session->eh_mutex);
return SUCCESS;
}
conn = session->leadconn;
iscsi_get_conn(conn->cls_conn);
conn->eh_abort_cnt++;
age = session->age;
ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n", sc, task->itt);
__iscsi_get_task(task);
spin_unlock(&session->back_lock);