From 0191e7405b687339a5540c1562acdecefd70eb3f Mon Sep 17 00:00:00 2001
From: James Smart <jsmart2021@gmail.com>
Date: Wed, 13 Mar 2019 18:55:03 +0100
Subject: [PATCH] nvmet-fc: fix issues with targetport assoc_list list walking
There are two changes:
1) The logic in the __nvmet_fc_free_assoc() routine is bad. It uses
"safe" routines assuming pointers will come back valid. However, the
intervening next structure being linked can be removed from the list and
the resulting safe pointers are bad, resulting in NULL ptrs being hit.
Correct by scheduling a work element to perform the association delete,
which can be done while under lock.
2) Prior patch that added the work element scheduling left a possible
reference on the object if the work element couldn't be scheduled.
Correct by doing the put on a failing schedule_work() call.
Signed-off-by: Nigel Kirkland <nigel.kirkland@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
drivers/nvme/target/fc.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c
index 1e9654f04c608..6b7bbf39fa067 100644
--- a/drivers/nvme/target/fc.c
+++ b/drivers/nvme/target/fc.c
@@ -1143,10 +1143,8 @@ __nvmet_fc_free_assocs(struct nvmet_fc_tgtport *tgtport)
&tgtport->assoc_list, a_list) {
if (!nvmet_fc_tgt_a_get(assoc))
continue;
- spin_unlock_irqrestore(&tgtport->lock, flags);
- nvmet_fc_delete_target_assoc(assoc);
- nvmet_fc_tgt_a_put(assoc);
- spin_lock_irqsave(&tgtport->lock, flags);
+ if (!schedule_work(&assoc->del_work))
+ nvmet_fc_tgt_a_put(assoc);
}
spin_unlock_irqrestore(&tgtport->lock, flags);
}
@@ -1185,7 +1183,8 @@ nvmet_fc_delete_ctrl(struct nvmet_ctrl *ctrl)
nvmet_fc_tgtport_put(tgtport);
if (found_ctrl) {
- schedule_work(&assoc->del_work);
+ if (!schedule_work(&assoc->del_work))
+ nvmet_fc_tgt_a_put(assoc);
return;
}
--
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