From: Roy Shterman Date: Mon, 25 Dec 2017 12:18:30 +0000 (+0200) Subject: nvme-fabrics: protect against module unload during create_ctrl X-Git-Tag: v4.15.17~114 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2c624d6fede9a0c3f2ae66518ab0e9847b3bd4fe;p=thirdparty%2Fkernel%2Fstable.git nvme-fabrics: protect against module unload during create_ctrl [ Upstream commit 0de5cd367c6aa2a31a1c931628f778f79f8ef22e ] NVMe transport driver module unload may (and usually does) trigger iteration over the active controllers and delete them all (sometimes under a mutex). However, a controller can be created concurrently with module unload which can lead to leakage of resources (most important char device node leakage) in case the controller creation occured after the unload delete and drain sequence. To protect against this, we take a module reference to guarantee that the nvme transport driver is not unloaded while creating a controller. Signed-off-by: Roy Shterman Signed-off-by: Sagi Grimberg Reviewed-by: Max Gurtovoy Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c index 894c2ccb3891e..4037fbf6457c0 100644 --- a/drivers/nvme/host/fabrics.c +++ b/drivers/nvme/host/fabrics.c @@ -493,7 +493,7 @@ EXPORT_SYMBOL_GPL(nvmf_should_reconnect); */ int nvmf_register_transport(struct nvmf_transport_ops *ops) { - if (!ops->create_ctrl) + if (!ops->create_ctrl || !ops->module) return -EINVAL; down_write(&nvmf_transports_rwsem); @@ -869,32 +869,41 @@ nvmf_create_ctrl(struct device *dev, const char *buf, size_t count) goto out_unlock; } + if (!try_module_get(ops->module)) { + ret = -EBUSY; + goto out_unlock; + } + ret = nvmf_check_required_opts(opts, ops->required_opts); if (ret) - goto out_unlock; + goto out_module_put; ret = nvmf_check_allowed_opts(opts, NVMF_ALLOWED_OPTS | ops->allowed_opts | ops->required_opts); if (ret) - goto out_unlock; + goto out_module_put; ctrl = ops->create_ctrl(dev, opts); if (IS_ERR(ctrl)) { ret = PTR_ERR(ctrl); - goto out_unlock; + goto out_module_put; } if (strcmp(ctrl->subsys->subnqn, opts->subsysnqn)) { dev_warn(ctrl->device, "controller returned incorrect NQN: \"%s\".\n", ctrl->subsys->subnqn); + module_put(ops->module); up_read(&nvmf_transports_rwsem); nvme_delete_ctrl_sync(ctrl); return ERR_PTR(-EINVAL); } + module_put(ops->module); up_read(&nvmf_transports_rwsem); return ctrl; +out_module_put: + module_put(ops->module); out_unlock: up_read(&nvmf_transports_rwsem); out_free_opts: diff --git a/drivers/nvme/host/fabrics.h b/drivers/nvme/host/fabrics.h index 9ba614953607e..25b19f722f5b2 100644 --- a/drivers/nvme/host/fabrics.h +++ b/drivers/nvme/host/fabrics.h @@ -108,6 +108,7 @@ struct nvmf_ctrl_options { * fabric implementation of NVMe fabrics. * @entry: Used by the fabrics library to add the new * registration entry to its linked-list internal tree. + * @module: Transport module reference * @name: Name of the NVMe fabric driver implementation. * @required_opts: sysfs command-line options that must be specified * when adding a new NVMe controller. @@ -126,6 +127,7 @@ struct nvmf_ctrl_options { */ struct nvmf_transport_ops { struct list_head entry; + struct module *module; const char *name; int required_opts; int allowed_opts; diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c index 794e66e4aa201..306aee47c8ce4 100644 --- a/drivers/nvme/host/fc.c +++ b/drivers/nvme/host/fc.c @@ -3380,6 +3380,7 @@ nvme_fc_create_ctrl(struct device *dev, struct nvmf_ctrl_options *opts) static struct nvmf_transport_ops nvme_fc_transport = { .name = "fc", + .module = THIS_MODULE, .required_opts = NVMF_OPT_TRADDR | NVMF_OPT_HOST_TRADDR, .allowed_opts = NVMF_OPT_RECONNECT_DELAY | NVMF_OPT_CTRL_LOSS_TMO, .create_ctrl = nvme_fc_create_ctrl, diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c index 2a0bba7f50cf4..d49b1e74f304f 100644 --- a/drivers/nvme/host/rdma.c +++ b/drivers/nvme/host/rdma.c @@ -2018,6 +2018,7 @@ out_free_ctrl: static struct nvmf_transport_ops nvme_rdma_transport = { .name = "rdma", + .module = THIS_MODULE, .required_opts = NVMF_OPT_TRADDR, .allowed_opts = NVMF_OPT_TRSVCID | NVMF_OPT_RECONNECT_DELAY | NVMF_OPT_HOST_TRADDR | NVMF_OPT_CTRL_LOSS_TMO, diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c index 1e21b286f2998..fdfcc961029f9 100644 --- a/drivers/nvme/target/loop.c +++ b/drivers/nvme/target/loop.c @@ -686,6 +686,7 @@ static struct nvmet_fabrics_ops nvme_loop_ops = { static struct nvmf_transport_ops nvme_loop_transport = { .name = "loop", + .module = THIS_MODULE, .create_ctrl = nvme_loop_create_ctrl, };