From: James Smart Date: Wed, 13 Mar 2019 17:55:03 +0000 (+0100) Subject: nvmet-fc: fix issues with targetport assoc_list list walking X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=0191e7405b687339a5540c1562acdecefd70eb3f;p=linux.git 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 Signed-off-by: James Smart Reviewed-by: Ewan D. Milne Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- 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; }