5.4-stable review patch. If anyone has any objections, please let me know.
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From: Sagi Grimberg sagi@grimberg.me
[ 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@grimberg.me Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Keith Busch kbusch@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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); }