[PATCH AUTOSEL 4.19 70/73] nvme: validate controller state before rescheduling keep alive

[PATCH AUTOSEL 4.19 70/73] nvme: validate controller state before rescheduling keep alive

[Sasha Levin]

From: James Smart <jsmart2021@gmail.com>

[ Upstream commit 86880d646122240596d6719b642fee3213239994 ]

Delete operations are seeing NULL pointer references in call_timer_fn.
Tracking these back, the timer appears to be the keep alive timer.

nvme_keep_alive_work() which is tied to the timer that is cancelled
by nvme_stop_keep_alive(), simply starts the keep alive io but doesn't
wait for it's completion. So nvme_stop_keep_alive() only stops a timer
when it's pending. When a keep alive is in flight, there is no timer
running and the nvme_stop_keep_alive() will have no affect on the keep
alive io. Thus, if the io completes successfully, the keep alive timer
will be rescheduled.   In the failure case, delete is called, the
controller state is changed, the nvme_stop_keep_alive() is called while
the io is outstanding, and the delete path continues on. The keep
alive happens to successfully complete before the delete paths mark it
as aborted as part of the queue termination, so the timer is restarted.
The delete paths then tear down the controller, and later on the timer
code fires and the timer entry is now corrupt.

Fix by validating the controller state before rescheduling the keep
alive. Testing with the fix has confirmed the condition above was hit.

Signed-off-by: James Smart <jsmart2021 at gmail.com>
Reviewed-by: Sagi Grimberg <sagi at grimberg.me>
Signed-off-by: Christoph Hellwig <hch at lst.de>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 drivers/nvme/host/core.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 0ba301f7e8b4..05bd7f49d6e0 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -831,6 +831,8 @@ static int nvme_submit_user_cmd(struct request_queue *q,
 static void nvme_keep_alive_end_io(struct request *rq, blk_status_t status)
 {
 	struct nvme_ctrl *ctrl = rq->end_io_data;
+	unsigned long flags;
+	bool startka = false;
 
 	blk_mq_free_request(rq);
 
@@ -841,7 +843,13 @@ static void nvme_keep_alive_end_io(struct request *rq, blk_status_t status)
 		return;
 	}
 
-	schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ);
+	spin_lock_irqsave(&ctrl->lock, flags);
+	if (ctrl->state == NVME_CTRL_LIVE ||
+	    ctrl->state == NVME_CTRL_CONNECTING)
+		startka = true;
+	spin_unlock_irqrestore(&ctrl->lock, flags);
+	if (startka)
+		schedule_delayed_work(&ctrl->ka_work, ctrl->kato * HZ);
 }
 
 static int nvme_keep_alive(struct nvme_ctrl *ctrl)
-- 
2.19.1

[PATCH AUTOSEL 4.19 71/73] nvmet-rdma: fix response use after free

[Sasha Levin]

From: Israel Rukshin <israelr@mellanox.com>

[ Upstream commit d7dcdf9d4e15189ecfda24cc87339a3425448d5c ]

nvmet_rdma_release_rsp() may free the response before using it at error
flow.

Fixes: 8407879 ("nvmet-rdma: fix possible bogus dereference under heavy load")
Signed-off-by: Israel Rukshin <israelr at mellanox.com>
Reviewed-by: Sagi Grimberg <sagi at grimberg.me>
Reviewed-by: Max Gurtovoy <maxg at mellanox.com>
Signed-off-by: Christoph Hellwig <hch at lst.de>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 drivers/nvme/target/rdma.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index bfc4da660bb4..e57f3902beb3 100644
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c
@@ -529,6 +529,7 @@ static void nvmet_rdma_send_done(struct ib_cq *cq, struct ib_wc *wc)
 {
 	struct nvmet_rdma_rsp *rsp =
 		container_of(wc->wr_cqe, struct nvmet_rdma_rsp, send_cqe);
+	struct nvmet_rdma_queue *queue = cq->cq_context;
 
 	nvmet_rdma_release_rsp(rsp);
 
@@ -536,7 +537,7 @@ static void nvmet_rdma_send_done(struct ib_cq *cq, struct ib_wc *wc)
 		     wc->status != IB_WC_WR_FLUSH_ERR)) {
 		pr_err("SEND for CQE 0x%p failed with status %s (%d).\n",
 			wc->wr_cqe, ib_wc_status_msg(wc->status), wc->status);
-		nvmet_rdma_error_comp(rsp->queue);
+		nvmet_rdma_error_comp(queue);
 	}
 }
 
-- 
2.19.1