From 63c47c286d062d93e0501d60797274c84a587e97 Mon Sep 17 00:00:00 2001 From: Roland Dreier Date: Mon, 26 Sep 2005 13:01:03 -0700 Subject: [PATCH] [IB] uverbs: Close some exploitable races Al Viro pointed out that the current IB userspace verbs interface allows userspace to cause mischief by closing file descriptors before we're ready, or issuing the same command twice at the same time. This patch closes those races, and fixes other obvious problems such as a module reference leak. Some other interface bogosities will require an ABI change to fix properly, so I'm deferring those fixes until 2.6.15. Signed-off-by: Roland Dreier --- drivers/infiniband/core/uverbs.h | 1 + drivers/infiniband/core/uverbs_cmd.c | 120 ++++++++++++++------------ drivers/infiniband/core/uverbs_main.c | 27 ++++-- include/rdma/ib_verbs.h | 1 - 4 files changed, 86 insertions(+), 63 deletions(-) diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uverbs.h index b1897bed14ad..cc124344dd2c 100644 --- a/drivers/infiniband/core/uverbs.h +++ b/drivers/infiniband/core/uverbs.h @@ -69,6 +69,7 @@ struct ib_uverbs_event_file { struct ib_uverbs_file { struct kref ref; + struct semaphore mutex; struct ib_uverbs_device *device; struct ib_ucontext *ucontext; struct ib_event_handler event_handler; diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c index e91ebde46481..562445165d2b 100644 --- a/drivers/infiniband/core/uverbs_cmd.c +++ b/drivers/infiniband/core/uverbs_cmd.c @@ -76,8 +76,9 @@ ssize_t ib_uverbs_get_context(struct ib_uverbs_file *file, struct ib_uverbs_get_context_resp resp; struct ib_udata udata; struct ib_device *ibdev = file->device->ib_dev; + struct ib_ucontext *ucontext; int i; - int ret = in_len; + int ret; if (out_len < sizeof resp) return -ENOSPC; @@ -85,45 +86,56 @@ ssize_t ib_uverbs_get_context(struct ib_uverbs_file *file, if (copy_from_user(&cmd, buf, sizeof cmd)) return -EFAULT; + down(&file->mutex); + + if (file->ucontext) { + ret = -EINVAL; + goto err; + } + INIT_UDATA(&udata, buf + sizeof cmd, (unsigned long) cmd.response + sizeof resp, in_len - sizeof cmd, out_len - sizeof resp); - file->ucontext = ibdev->alloc_ucontext(ibdev, &udata); - if (IS_ERR(file->ucontext)) { - ret = PTR_ERR(file->ucontext); - file->ucontext = NULL; - return ret; - } + ucontext = ibdev->alloc_ucontext(ibdev, &udata); + if (IS_ERR(ucontext)) + return PTR_ERR(file->ucontext); - file->ucontext->device = ibdev; - INIT_LIST_HEAD(&file->ucontext->pd_list); - INIT_LIST_HEAD(&file->ucontext->mr_list); - INIT_LIST_HEAD(&file->ucontext->mw_list); - INIT_LIST_HEAD(&file->ucontext->cq_list); - INIT_LIST_HEAD(&file->ucontext->qp_list); - INIT_LIST_HEAD(&file->ucontext->srq_list); - INIT_LIST_HEAD(&file->ucontext->ah_list); - spin_lock_init(&file->ucontext->lock); + ucontext->device = ibdev; + INIT_LIST_HEAD(&ucontext->pd_list); + INIT_LIST_HEAD(&ucontext->mr_list); + INIT_LIST_HEAD(&ucontext->mw_list); + INIT_LIST_HEAD(&ucontext->cq_list); + INIT_LIST_HEAD(&ucontext->qp_list); + INIT_LIST_HEAD(&ucontext->srq_list); + INIT_LIST_HEAD(&ucontext->ah_list); resp.async_fd = file->async_file.fd; for (i = 0; i < file->device->num_comp; ++i) if (copy_to_user((void __user *) (unsigned long) cmd.cq_fd_tab + i * sizeof (__u32), - &file->comp_file[i].fd, sizeof (__u32))) - goto err; + &file->comp_file[i].fd, sizeof (__u32))) { + ret = -EFAULT; + goto err_free; + } if (copy_to_user((void __user *) (unsigned long) cmd.response, - &resp, sizeof resp)) - goto err; + &resp, sizeof resp)) { + ret = -EFAULT; + goto err_free; + } + + file->ucontext = ucontext; + up(&file->mutex); return in_len; -err: - ibdev->dealloc_ucontext(file->ucontext); - file->ucontext = NULL; +err_free: + ibdev->dealloc_ucontext(ucontext); - return -EFAULT; +err: + up(&file->mutex); + return ret; } ssize_t ib_uverbs_query_device(struct ib_uverbs_file *file, @@ -352,9 +364,9 @@ ssize_t ib_uverbs_alloc_pd(struct ib_uverbs_file *file, if (ret) goto err_pd; - spin_lock_irq(&file->ucontext->lock); + down(&file->mutex); list_add_tail(&uobj->list, &file->ucontext->pd_list); - spin_unlock_irq(&file->ucontext->lock); + up(&file->mutex); memset(&resp, 0, sizeof resp); resp.pd_handle = uobj->id; @@ -368,9 +380,9 @@ ssize_t ib_uverbs_alloc_pd(struct ib_uverbs_file *file, return in_len; err_list: - spin_lock_irq(&file->ucontext->lock); + down(&file->mutex); list_del(&uobj->list); - spin_unlock_irq(&file->ucontext->lock); + up(&file->mutex); down(&ib_uverbs_idr_mutex); idr_remove(&ib_uverbs_pd_idr, uobj->id); @@ -410,9 +422,9 @@ ssize_t ib_uverbs_dealloc_pd(struct ib_uverbs_file *file, idr_remove(&ib_uverbs_pd_idr, cmd.pd_handle); - spin_lock_irq(&file->ucontext->lock); + down(&file->mutex); list_del(&uobj->list); - spin_unlock_irq(&file->ucontext->lock); + up(&file->mutex); kfree(uobj); @@ -512,9 +524,9 @@ ssize_t ib_uverbs_reg_mr(struct ib_uverbs_file *file, resp.mr_handle = obj->uobject.id; - spin_lock_irq(&file->ucontext->lock); + down(&file->mutex); list_add_tail(&obj->uobject.list, &file->ucontext->mr_list); - spin_unlock_irq(&file->ucontext->lock); + up(&file->mutex); if (copy_to_user((void __user *) (unsigned long) cmd.response, &resp, sizeof resp)) { @@ -527,9 +539,9 @@ ssize_t ib_uverbs_reg_mr(struct ib_uverbs_file *file, return in_len; err_list: - spin_lock_irq(&file->ucontext->lock); + down(&file->mutex); list_del(&obj->uobject.list); - spin_unlock_irq(&file->ucontext->lock); + up(&file->mutex); err_unreg: ib_dereg_mr(mr); @@ -570,9 +582,9 @@ ssize_t ib_uverbs_dereg_mr(struct ib_uverbs_file *file, idr_remove(&ib_uverbs_mr_idr, cmd.mr_handle); - spin_lock_irq(&file->ucontext->lock); + down(&file->mutex); list_del(&memobj->uobject.list); - spin_unlock_irq(&file->ucontext->lock); + up(&file->mutex); ib_umem_release(file->device->ib_dev, &memobj->umem); kfree(memobj); @@ -647,9 +659,9 @@ ssize_t ib_uverbs_create_cq(struct ib_uverbs_file *file, if (ret) goto err_cq; - spin_lock_irq(&file->ucontext->lock); + down(&file->mutex); list_add_tail(&uobj->uobject.list, &file->ucontext->cq_list); - spin_unlock_irq(&file->ucontext->lock); + up(&file->mutex); memset(&resp, 0, sizeof resp); resp.cq_handle = uobj->uobject.id; @@ -664,9 +676,9 @@ ssize_t ib_uverbs_create_cq(struct ib_uverbs_file *file, return in_len; err_list: - spin_lock_irq(&file->ucontext->lock); + down(&file->mutex); list_del(&uobj->uobject.list); - spin_unlock_irq(&file->ucontext->lock); + up(&file->mutex); down(&ib_uverbs_idr_mutex); idr_remove(&ib_uverbs_cq_idr, uobj->uobject.id); @@ -712,9 +724,9 @@ ssize_t ib_uverbs_destroy_cq(struct ib_uverbs_file *file, idr_remove(&ib_uverbs_cq_idr, cmd.cq_handle); - spin_lock_irq(&file->ucontext->lock); + down(&file->mutex); list_del(&uobj->uobject.list); - spin_unlock_irq(&file->ucontext->lock); + up(&file->mutex); spin_lock_irq(&file->comp_file[0].lock); list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) { @@ -847,9 +859,9 @@ ssize_t ib_uverbs_create_qp(struct ib_uverbs_file *file, resp.qp_handle = uobj->uobject.id; - spin_lock_irq(&file->ucontext->lock); + down(&file->mutex); list_add_tail(&uobj->uobject.list, &file->ucontext->qp_list); - spin_unlock_irq(&file->ucontext->lock); + up(&file->mutex); if (copy_to_user((void __user *) (unsigned long) cmd.response, &resp, sizeof resp)) { @@ -862,9 +874,9 @@ ssize_t ib_uverbs_create_qp(struct ib_uverbs_file *file, return in_len; err_list: - spin_lock_irq(&file->ucontext->lock); + down(&file->mutex); list_del(&uobj->uobject.list); - spin_unlock_irq(&file->ucontext->lock); + up(&file->mutex); err_destroy: ib_destroy_qp(qp); @@ -989,9 +1001,9 @@ ssize_t ib_uverbs_destroy_qp(struct ib_uverbs_file *file, idr_remove(&ib_uverbs_qp_idr, cmd.qp_handle); - spin_lock_irq(&file->ucontext->lock); + down(&file->mutex); list_del(&uobj->uobject.list); - spin_unlock_irq(&file->ucontext->lock); + up(&file->mutex); spin_lock_irq(&file->async_file.lock); list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) { @@ -1136,9 +1148,9 @@ ssize_t ib_uverbs_create_srq(struct ib_uverbs_file *file, resp.srq_handle = uobj->uobject.id; - spin_lock_irq(&file->ucontext->lock); + down(&file->mutex); list_add_tail(&uobj->uobject.list, &file->ucontext->srq_list); - spin_unlock_irq(&file->ucontext->lock); + up(&file->mutex); if (copy_to_user((void __user *) (unsigned long) cmd.response, &resp, sizeof resp)) { @@ -1151,9 +1163,9 @@ ssize_t ib_uverbs_create_srq(struct ib_uverbs_file *file, return in_len; err_list: - spin_lock_irq(&file->ucontext->lock); + down(&file->mutex); list_del(&uobj->uobject.list); - spin_unlock_irq(&file->ucontext->lock); + up(&file->mutex); err_destroy: ib_destroy_srq(srq); @@ -1227,9 +1239,9 @@ ssize_t ib_uverbs_destroy_srq(struct ib_uverbs_file *file, idr_remove(&ib_uverbs_srq_idr, cmd.srq_handle); - spin_lock_irq(&file->ucontext->lock); + down(&file->mutex); list_del(&uobj->uobject.list); - spin_unlock_irq(&file->ucontext->lock); + up(&file->mutex); spin_lock_irq(&file->async_file.lock); list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) { diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c index ce5bdb7af306..12511808de21 100644 --- a/drivers/infiniband/core/uverbs_main.c +++ b/drivers/infiniband/core/uverbs_main.c @@ -448,7 +448,9 @@ static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf, if (hdr.in_words * 4 != count) return -EINVAL; - if (hdr.command < 0 || hdr.command >= ARRAY_SIZE(uverbs_cmd_table)) + if (hdr.command < 0 || + hdr.command >= ARRAY_SIZE(uverbs_cmd_table) || + !uverbs_cmd_table[hdr.command]) return -EINVAL; if (!file->ucontext && @@ -484,27 +486,29 @@ static int ib_uverbs_open(struct inode *inode, struct file *filp) file = kmalloc(sizeof *file + (dev->num_comp - 1) * sizeof (struct ib_uverbs_event_file), GFP_KERNEL); - if (!file) - return -ENOMEM; + if (!file) { + ret = -ENOMEM; + goto err; + } file->device = dev; kref_init(&file->ref); + init_MUTEX(&file->mutex); file->ucontext = NULL; + kref_get(&file->ref); ret = ib_uverbs_event_init(&file->async_file, file); if (ret) - goto err; + goto err_kref; file->async_file.is_async = 1; - kref_get(&file->ref); - for (i = 0; i < dev->num_comp; ++i) { + kref_get(&file->ref); ret = ib_uverbs_event_init(&file->comp_file[i], file); if (ret) goto err_async; - kref_get(&file->ref); file->comp_file[i].is_async = 0; } @@ -524,9 +528,16 @@ static int ib_uverbs_open(struct inode *inode, struct file *filp) ib_uverbs_event_release(&file->async_file); -err: +err_kref: + /* + * One extra kref_put() because we took a reference before the + * event file creation that failed and got us here. + */ + kref_put(&file->ref, ib_uverbs_release_file); kref_put(&file->ref, ib_uverbs_release_file); +err: + module_put(dev->ib_dev->owner); return ret; } diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index e16cf94870f2..e6f4c9e55df7 100644 --- a/include/rdma/ib_verbs.h +++ b/include/rdma/ib_verbs.h @@ -665,7 +665,6 @@ struct ib_ucontext { struct list_head qp_list; struct list_head srq_list; struct list_head ah_list; - spinlock_t lock; }; struct ib_uobject {