5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sagi Grimberg <sagi@xxxxxxxxxxx>
[ Upstream commit 73964c1d07c054376f1b32a62548571795159148 ]
It is possible that the host connected and saw a cm established
event and started sending nvme capsules on the qp, however the
ctrl did not yet see an established event. This is why the
rsp_wait_list exists (for async handling of these cmds, we move
them to a pending list).
Furthermore, it is possible that the ctrl cm times out, resulting
in a connect-error cm event. in this case we hit a bad deref [1]
because in nvmet_rdma_free_rsps we assume that all the responses
are in the free list.
We are freeing the cmds array anyways, so don't even bother to
remove the rsp from the free_list. It is also guaranteed that we
are not racing anything when we are releasing the queue so no
other context accessing this array should be running.
[1]:
--
Workqueue: nvmet-free-wq nvmet_rdma_free_queue_work [nvmet_rdma]
[...]
pc : nvmet_rdma_free_rsps+0x78/0xb8 [nvmet_rdma]
lr : nvmet_rdma_free_queue_work+0x88/0x120 [nvmet_rdma]
Call trace:
nvmet_rdma_free_rsps+0x78/0xb8 [nvmet_rdma]
nvmet_rdma_free_queue_work+0x88/0x120 [nvmet_rdma]
process_one_work+0x1ec/0x4a0
worker_thread+0x48/0x490
kthread+0x158/0x160
ret_from_fork+0x10/0x18
--
Signed-off-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/nvme/target/rdma.c | 16 ++++------------
1 file changed, 4 insertions(+), 12 deletions(-)
diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index 50e2007092bc0..ae41b6001c7e2 100644
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c
@@ -428,12 +428,8 @@ nvmet_rdma_alloc_rsps(struct nvmet_rdma_queue *queue)
return 0;
out_free:
- while (--i >= 0) {
- struct nvmet_rdma_rsp *rsp = &queue->rsps[i];
-
- list_del(&rsp->free_list);
- nvmet_rdma_free_rsp(ndev, rsp);
- }
+ while (--i >= 0)
+ nvmet_rdma_free_rsp(ndev, &queue->rsps[i]);
kfree(queue->rsps);
out:
return ret;
@@ -444,12 +440,8 @@ static void nvmet_rdma_free_rsps(struct nvmet_rdma_queue *queue)
struct nvmet_rdma_device *ndev = queue->dev;
int i, nr_rsps = queue->recv_queue_size * 2;
- for (i = 0; i < nr_rsps; i++) {
- struct nvmet_rdma_rsp *rsp = &queue->rsps[i];
-
- list_del(&rsp->free_list);
- nvmet_rdma_free_rsp(ndev, rsp);
- }
+ for (i = 0; i < nr_rsps; i++)
+ nvmet_rdma_free_rsp(ndev, &queue->rsps[i]);
kfree(queue->rsps);
}
--
2.43.0
