From: Israel Rukshin israelr@mellanox.com
commit 1a3f540d63152b8db0a12de508bfa03776217d83 upstream.
After nvmet_install_queue() sets sq->ctrl calling to nvmet_sq_destroy() reduces the controller refcount. In case nvmet_install_queue() fails, calling to nvmet_ctrl_put() is done twice (at nvmet_sq_destroy and nvmet_execute_io_connect/nvmet_execute_admin_connect) instead of once for the queue which leads to use after free of the controller. Fix this by set NULL at sq->ctrl in case of a failure at nvmet_install_queue().
The bug leads to the following Call Trace:
[65857.994862] refcount_t: underflow; use-after-free. [65858.108304] Workqueue: events nvmet_rdma_release_queue_work [nvmet_rdma] [65858.115557] RIP: 0010:refcount_warn_saturate+0xe5/0xf0 [65858.208141] Call Trace: [65858.211203] nvmet_sq_destroy+0xe1/0xf0 [nvmet] [65858.216383] nvmet_rdma_release_queue_work+0x37/0xf0 [nvmet_rdma] [65858.223117] process_one_work+0x167/0x370 [65858.227776] worker_thread+0x49/0x3e0 [65858.232089] kthread+0xf5/0x130 [65858.235895] ? max_active_store+0x80/0x80 [65858.240504] ? kthread_bind+0x10/0x10 [65858.244832] ret_from_fork+0x1f/0x30 [65858.249074] ---[ end trace f82d59250b54beb7 ]---
Fixes: bb1cc74790eb ("nvmet: implement valid sqhd values in completions") Fixes: 1672ddb8d691 ("nvmet: Add install_queue callout") Signed-off-by: Israel Rukshin israelr@mellanox.com Reviewed-by: Max Gurtovoy maxg@mellanox.com Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Keith Busch kbusch@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/nvme/target/fabrics-cmd.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
--- a/drivers/nvme/target/fabrics-cmd.c +++ b/drivers/nvme/target/fabrics-cmd.c @@ -105,6 +105,7 @@ static u16 nvmet_install_queue(struct nv u16 qid = le16_to_cpu(c->qid); u16 sqsize = le16_to_cpu(c->sqsize); struct nvmet_ctrl *old; + u16 ret;
old = cmpxchg(&req->sq->ctrl, NULL, ctrl); if (old) { @@ -115,7 +116,8 @@ static u16 nvmet_install_queue(struct nv if (!sqsize) { pr_warn("queue size zero!\n"); req->error_loc = offsetof(struct nvmf_connect_command, sqsize); - return NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR; + ret = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR; + goto err; }
/* note: convert queue size from 0's-based value to 1's-based value */ @@ -128,16 +130,19 @@ static u16 nvmet_install_queue(struct nv }
if (ctrl->ops->install_queue) { - u16 ret = ctrl->ops->install_queue(req->sq); - + ret = ctrl->ops->install_queue(req->sq); if (ret) { pr_err("failed to install queue %d cntlid %d ret %x\n", qid, ctrl->cntlid, ret); - return ret; + goto err; } }
return 0; + +err: + req->sq->ctrl = NULL; + return ret; }
static void nvmet_execute_admin_connect(struct nvmet_req *req)