From 2016d94229643506fee6b47783f1125c4921491d Mon Sep 17 00:00:00 2001 From: Desmond Cheong Zhi Xi Date: Thu, 21 Oct 2021 21:03:25 +0800 Subject: [PATCH 1/3] drm: serialize drm_file.master with a new spinlock Commit f57ea7452ea2f66a2d2ed3d50ff6f5cabef7bd23 CVE: CVE-2022-1280 Signed-off-by: Fang Minjuan --------------------------------- stable inclusion from stable-5.10.67 commit 06a553a99bacb00d3bc25f79e75c8e0fbf7a5025 bugzilla: 182619 https://gitee.com/openeuler/kernel/issues/I4EWO7 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=06a553a99bacb00d3bc25f79e75c8e0fbf7a5025 -------------------------------- [ Upstream commit 0b0860a3cf5eccf183760b1177a1dcdb821b0b66 ] Currently, drm_file.master pointers should be protected by drm_device.master_mutex when being dereferenced. This is because drm_file.master is not invariant for the lifetime of drm_file. If drm_file is not the creator of master, then drm_file.is_master is false, and a call to drm_setmaster_ioctl will invoke drm_new_set_master, which then allocates a new master for drm_file and puts the old master. Thus, without holding drm_device.master_mutex, the old value of drm_file.master could be freed while it is being used by another concurrent process. However, it is not always possible to lock drm_device.master_mutex to dereference drm_file.master. Through the fbdev emulation code, this might occur in a deep nest of other locks. But drm_device.master_mutex is also the outermost lock in the nesting hierarchy, so this leads to potential deadlocks. To address this, we introduce a new spin lock at the bottom of the lock hierarchy that only serializes drm_file.master. With this change, the value of drm_file.master changes only when both drm_device.master_mutex and drm_file.master_lookup_lock are held. Hence, any process holding either of those locks can ensure that the value of drm_file.master will not change concurrently. Since no lock depends on the new drm_file.master_lookup_lock, when drm_file.master is dereferenced, but drm_device.master_mutex cannot be held, we can safely protect the master pointer with drm_file.master_lookup_lock. Reported-by: Daniel Vetter Signed-off-by: Desmond Cheong Zhi Xi Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20210712043508.11584-5-desmondcheongzx@gmail.com Signed-off-by: Sasha Levin Signed-off-by: Chen Jun Acked-by: Weilong Chen Signed-off-by: Chen Jun Signed-off-by: Zheng Zengkai --- drivers/gpu/drm/drm_auth.c | 17 +++++++++++------ drivers/gpu/drm/drm_file.c | 1 + include/drm/drm_file.h | 12 +++++++++--- 3 files changed, 21 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c index 232abbba3686..0024ad93d24b 100644 --- a/drivers/gpu/drm/drm_auth.c +++ b/drivers/gpu/drm/drm_auth.c @@ -135,16 +135,18 @@ static void drm_set_master(struct drm_device *dev, struct drm_file *fpriv, static int drm_new_set_master(struct drm_device *dev, struct drm_file *fpriv) { struct drm_master *old_master; + struct drm_master *new_master; lockdep_assert_held_once(&dev->master_mutex); WARN_ON(fpriv->is_master); old_master = fpriv->master; - fpriv->master = drm_master_create(dev); - if (!fpriv->master) { - fpriv->master = old_master; + new_master = drm_master_create(dev); + if (!new_master) return -ENOMEM; - } + spin_lock(&fpriv->master_lookup_lock); + fpriv->master = new_master; + spin_unlock(&fpriv->master_lookup_lock); fpriv->is_master = 1; fpriv->authenticated = 1; @@ -302,10 +304,13 @@ int drm_master_open(struct drm_file *file_priv) /* if there is no current master make this fd it, but do not create * any master object for render clients */ mutex_lock(&dev->master_mutex); - if (!dev->master) + if (!dev->master) { ret = drm_new_set_master(dev, file_priv); - else + } else { + spin_lock(&file_priv->master_lookup_lock); file_priv->master = drm_master_get(dev->master); + spin_unlock(&file_priv->master_lookup_lock); + } mutex_unlock(&dev->master_mutex); return ret; diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c index 0ac4566ae3f4..537e7de8e9c3 100644 --- a/drivers/gpu/drm/drm_file.c +++ b/drivers/gpu/drm/drm_file.c @@ -177,6 +177,7 @@ struct drm_file *drm_file_alloc(struct drm_minor *minor) init_waitqueue_head(&file->event_wait); file->event_space = 4096; /* set aside 4k for event buffer */ + spin_lock_init(&file->master_lookup_lock); mutex_init(&file->event_read_lock); if (drm_core_check_feature(dev, DRIVER_GEM)) diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h index 716990bace10..ca659ece3ee8 100644 --- a/include/drm/drm_file.h +++ b/include/drm/drm_file.h @@ -226,15 +226,21 @@ struct drm_file { /** * @master: * - * Master this node is currently associated with. Only relevant if - * drm_is_primary_client() returns true. Note that this only - * matches &drm_device.master if the master is the currently active one. + * Master this node is currently associated with. Protected by struct + * &drm_device.master_mutex, and serialized by @master_lookup_lock. + * + * Only relevant if drm_is_primary_client() returns true. Note that + * this only matches &drm_device.master if the master is the currently + * active one. * * See also @authentication and @is_master and the :ref:`section on * primary nodes and authentication `. */ struct drm_master *master; + /** @master_lock: Serializes @master. */ + spinlock_t master_lookup_lock; + /** @pid: Process that opened this file. */ struct pid *pid; -- Gitee From 7dc8cc4d4999d7600b62352ba192fcaf3a742b41 Mon Sep 17 00:00:00 2001 From: Desmond Cheong Zhi Xi Date: Thu, 21 Oct 2021 21:03:26 +0800 Subject: [PATCH 2/3] drm: protect drm_master pointers in drm_lease.c Commit 5fce34d43d149ef06a8e2dca01fe2e992c58a706 CVE: CVE-2022-1280 Signed-off-by: Fang Minjuan --------------------------------- stable inclusion from stable-5.10.67 commit 34609faad0c9f9f08d4b59d25c94b78bf5710d93 bugzilla: 182619 https://gitee.com/openeuler/kernel/issues/I4EWO7 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=34609faad0c9f9f08d4b59d25c94b78bf5710d93 -------------------------------- [ Upstream commit 56f0729a510f92151682ff6c89f69724d5595d6e ] drm_file->master pointers should be protected by drm_device.master_mutex or drm_file.master_lookup_lock when being dereferenced. However, in drm_lease.c, there are multiple instances where drm_file->master is accessed and dereferenced while neither lock is held. This makes drm_lease.c vulnerable to use-after-free bugs. We address this issue in 2 ways: 1. Add a new drm_file_get_master() function that calls drm_master_get on drm_file->master while holding on to drm_file.master_lookup_lock. Since drm_master_get increments the reference count of master, this prevents master from being freed until we unreference it with drm_master_put. 2. In each case where drm_file->master is directly accessed and eventually dereferenced in drm_lease.c, we wrap the access in a call to the new drm_file_get_master function, then unreference the master pointer once we are done using it. Reported-by: Daniel Vetter Signed-off-by: Desmond Cheong Zhi Xi Reviewed-by: Emil Velikov Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20210712043508.11584-6-desmondcheongzx@gmail.com Signed-off-by: Sasha Levin Signed-off-by: Chen Jun Acked-by: Weilong Chen Signed-off-by: Chen Jun Signed-off-by: Zheng Zengkai --- drivers/gpu/drm/drm_auth.c | 25 ++++++++++++ drivers/gpu/drm/drm_lease.c | 81 ++++++++++++++++++++++++++++--------- include/drm/drm_auth.h | 1 + include/drm/drm_file.h | 6 +++ 4 files changed, 93 insertions(+), 20 deletions(-) diff --git a/drivers/gpu/drm/drm_auth.c b/drivers/gpu/drm/drm_auth.c index 0024ad93d24b..c7adbeaf10b1 100644 --- a/drivers/gpu/drm/drm_auth.c +++ b/drivers/gpu/drm/drm_auth.c @@ -376,6 +376,31 @@ struct drm_master *drm_master_get(struct drm_master *master) } EXPORT_SYMBOL(drm_master_get); +/** + * drm_file_get_master - reference &drm_file.master of @file_priv + * @file_priv: DRM file private + * + * Increments the reference count of @file_priv's &drm_file.master and returns + * the &drm_file.master. If @file_priv has no &drm_file.master, returns NULL. + * + * Master pointers returned from this function should be unreferenced using + * drm_master_put(). + */ +struct drm_master *drm_file_get_master(struct drm_file *file_priv) +{ + struct drm_master *master = NULL; + + spin_lock(&file_priv->master_lookup_lock); + if (!file_priv->master) + goto unlock; + master = drm_master_get(file_priv->master); + +unlock: + spin_unlock(&file_priv->master_lookup_lock); + return master; +} +EXPORT_SYMBOL(drm_file_get_master); + static void drm_master_destroy(struct kref *kref) { struct drm_master *master = container_of(kref, struct drm_master, refcount); diff --git a/drivers/gpu/drm/drm_lease.c b/drivers/gpu/drm/drm_lease.c index da4f085fc09e..aef22634005e 100644 --- a/drivers/gpu/drm/drm_lease.c +++ b/drivers/gpu/drm/drm_lease.c @@ -107,10 +107,19 @@ static bool _drm_has_leased(struct drm_master *master, int id) */ bool _drm_lease_held(struct drm_file *file_priv, int id) { - if (!file_priv || !file_priv->master) + bool ret; + struct drm_master *master; + + if (!file_priv) return true; - return _drm_lease_held_master(file_priv->master, id); + master = drm_file_get_master(file_priv); + if (!master) + return true; + ret = _drm_lease_held_master(master, id); + drm_master_put(&master); + + return ret; } /** @@ -129,13 +138,22 @@ bool drm_lease_held(struct drm_file *file_priv, int id) struct drm_master *master; bool ret; - if (!file_priv || !file_priv->master || !file_priv->master->lessor) + if (!file_priv) return true; - master = file_priv->master; + master = drm_file_get_master(file_priv); + if (!master) + return true; + if (!master->lessor) { + ret = true; + goto out; + } mutex_lock(&master->dev->mode_config.idr_mutex); ret = _drm_lease_held_master(master, id); mutex_unlock(&master->dev->mode_config.idr_mutex); + +out: + drm_master_put(&master); return ret; } @@ -155,10 +173,16 @@ uint32_t drm_lease_filter_crtcs(struct drm_file *file_priv, uint32_t crtcs_in) int count_in, count_out; uint32_t crtcs_out = 0; - if (!file_priv || !file_priv->master || !file_priv->master->lessor) + if (!file_priv) return crtcs_in; - master = file_priv->master; + master = drm_file_get_master(file_priv); + if (!master) + return crtcs_in; + if (!master->lessor) { + crtcs_out = crtcs_in; + goto out; + } dev = master->dev; count_in = count_out = 0; @@ -177,6 +201,9 @@ uint32_t drm_lease_filter_crtcs(struct drm_file *file_priv, uint32_t crtcs_in) count_in++; } mutex_unlock(&master->dev->mode_config.idr_mutex); + +out: + drm_master_put(&master); return crtcs_out; } @@ -490,7 +517,7 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev, size_t object_count; int ret = 0; struct idr leases; - struct drm_master *lessor = lessor_priv->master; + struct drm_master *lessor; struct drm_master *lessee = NULL; struct file *lessee_file = NULL; struct file *lessor_file = lessor_priv->filp; @@ -502,12 +529,6 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev, if (!drm_core_check_feature(dev, DRIVER_MODESET)) return -EOPNOTSUPP; - /* Do not allow sub-leases */ - if (lessor->lessor) { - DRM_DEBUG_LEASE("recursive leasing not allowed\n"); - return -EINVAL; - } - /* need some objects */ if (cl->object_count == 0) { DRM_DEBUG_LEASE("no objects in lease\n"); @@ -519,12 +540,22 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev, return -EINVAL; } + lessor = drm_file_get_master(lessor_priv); + /* Do not allow sub-leases */ + if (lessor->lessor) { + DRM_DEBUG_LEASE("recursive leasing not allowed\n"); + ret = -EINVAL; + goto out_lessor; + } + object_count = cl->object_count; object_ids = memdup_user(u64_to_user_ptr(cl->object_ids), array_size(object_count, sizeof(__u32))); - if (IS_ERR(object_ids)) - return PTR_ERR(object_ids); + if (IS_ERR(object_ids)) { + ret = PTR_ERR(object_ids); + goto out_lessor; + } idr_init(&leases); @@ -535,14 +566,15 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev, if (ret) { DRM_DEBUG_LEASE("lease object lookup failed: %i\n", ret); idr_destroy(&leases); - return ret; + goto out_lessor; } /* Allocate a file descriptor for the lease */ fd = get_unused_fd_flags(cl->flags & (O_CLOEXEC | O_NONBLOCK)); if (fd < 0) { idr_destroy(&leases); - return fd; + ret = fd; + goto out_lessor; } DRM_DEBUG_LEASE("Creating lease\n"); @@ -578,6 +610,7 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev, /* Hook up the fd */ fd_install(fd, lessee_file); + drm_master_put(&lessor); DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl succeeded\n"); return 0; @@ -587,6 +620,8 @@ int drm_mode_create_lease_ioctl(struct drm_device *dev, out_leases: put_unused_fd(fd); +out_lessor: + drm_master_put(&lessor); DRM_DEBUG_LEASE("drm_mode_create_lease_ioctl failed: %d\n", ret); return ret; } @@ -609,7 +644,7 @@ int drm_mode_list_lessees_ioctl(struct drm_device *dev, struct drm_mode_list_lessees *arg = data; __u32 __user *lessee_ids = (__u32 __user *) (uintptr_t) (arg->lessees_ptr); __u32 count_lessees = arg->count_lessees; - struct drm_master *lessor = lessor_priv->master, *lessee; + struct drm_master *lessor, *lessee; int count; int ret = 0; @@ -620,6 +655,7 @@ int drm_mode_list_lessees_ioctl(struct drm_device *dev, if (!drm_core_check_feature(dev, DRIVER_MODESET)) return -EOPNOTSUPP; + lessor = drm_file_get_master(lessor_priv); DRM_DEBUG_LEASE("List lessees for %d\n", lessor->lessee_id); mutex_lock(&dev->mode_config.idr_mutex); @@ -643,6 +679,7 @@ int drm_mode_list_lessees_ioctl(struct drm_device *dev, arg->count_lessees = count; mutex_unlock(&dev->mode_config.idr_mutex); + drm_master_put(&lessor); return ret; } @@ -662,7 +699,7 @@ int drm_mode_get_lease_ioctl(struct drm_device *dev, struct drm_mode_get_lease *arg = data; __u32 __user *object_ids = (__u32 __user *) (uintptr_t) (arg->objects_ptr); __u32 count_objects = arg->count_objects; - struct drm_master *lessee = lessee_priv->master; + struct drm_master *lessee; struct idr *object_idr; int count; void *entry; @@ -676,6 +713,7 @@ int drm_mode_get_lease_ioctl(struct drm_device *dev, if (!drm_core_check_feature(dev, DRIVER_MODESET)) return -EOPNOTSUPP; + lessee = drm_file_get_master(lessee_priv); DRM_DEBUG_LEASE("get lease for %d\n", lessee->lessee_id); mutex_lock(&dev->mode_config.idr_mutex); @@ -703,6 +741,7 @@ int drm_mode_get_lease_ioctl(struct drm_device *dev, arg->count_objects = count; mutex_unlock(&dev->mode_config.idr_mutex); + drm_master_put(&lessee); return ret; } @@ -721,7 +760,7 @@ int drm_mode_revoke_lease_ioctl(struct drm_device *dev, void *data, struct drm_file *lessor_priv) { struct drm_mode_revoke_lease *arg = data; - struct drm_master *lessor = lessor_priv->master; + struct drm_master *lessor; struct drm_master *lessee; int ret = 0; @@ -731,6 +770,7 @@ int drm_mode_revoke_lease_ioctl(struct drm_device *dev, if (!drm_core_check_feature(dev, DRIVER_MODESET)) return -EOPNOTSUPP; + lessor = drm_file_get_master(lessor_priv); mutex_lock(&dev->mode_config.idr_mutex); lessee = _drm_find_lessee(lessor, arg->lessee_id); @@ -751,6 +791,7 @@ int drm_mode_revoke_lease_ioctl(struct drm_device *dev, fail: mutex_unlock(&dev->mode_config.idr_mutex); + drm_master_put(&lessor); return ret; } diff --git a/include/drm/drm_auth.h b/include/drm/drm_auth.h index 6bf8b2b78991..f99d3417f304 100644 --- a/include/drm/drm_auth.h +++ b/include/drm/drm_auth.h @@ -107,6 +107,7 @@ struct drm_master { }; struct drm_master *drm_master_get(struct drm_master *master); +struct drm_master *drm_file_get_master(struct drm_file *file_priv); void drm_master_put(struct drm_master **master); bool drm_is_current_master(struct drm_file *fpriv); diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h index ca659ece3ee8..42d04607d091 100644 --- a/include/drm/drm_file.h +++ b/include/drm/drm_file.h @@ -233,6 +233,12 @@ struct drm_file { * this only matches &drm_device.master if the master is the currently * active one. * + * When dereferencing this pointer, either hold struct + * &drm_device.master_mutex for the duration of the pointer's use, or + * use drm_file_get_master() if struct &drm_device.master_mutex is not + * currently held and there is no other need to hold it. This prevents + * @master from being freed during use. + * * See also @authentication and @is_master and the :ref:`section on * primary nodes and authentication `. */ -- Gitee From b5c41c999378baef0fa47eab85fe7cef1c9dbaea Mon Sep 17 00:00:00 2001 From: Zhang Yi Date: Mon, 15 Nov 2021 19:40:33 +0800 Subject: [PATCH 3/3] quota: check block number when reading the block in quota file Commit a5acbf8b1ddeac32d63163f92a3f2464225ca091 CVE: CVE-2021-45868 Signed-off-by: Fang Minjuan --------------------------- hulk inclusion category: bugfix bugzilla: 182754 https://gitee.com/openeuler/kernel/issues/I4DDEL --------------------------- The block number in the quota tree on disk should be smaller than the v2_disk_dqinfo.dqi_blocks. If the quota file was corrupted, we may be allocating an 'allocated' block and that would lead to a loop in a tree, which will probably trigger oops later. This patch adds a check for the block number in the quota tree to prevent such potential issue. Link: https://lore.kernel.org/r/20211008093821.1001186-2-yi.zhang@huawei.com Signed-off-by: Zhang Yi Cc: stable@kernel.org Signed-off-by: Jan Kara Reviewed-by: Yang Erkun Signed-off-by: Chen Jun Signed-off-by: Zheng Zengkai --- fs/quota/quota_tree.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/fs/quota/quota_tree.c b/fs/quota/quota_tree.c index c5562c871c8b..c459ac0cb2c7 100644 --- a/fs/quota/quota_tree.c +++ b/fs/quota/quota_tree.c @@ -488,6 +488,13 @@ static int remove_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot, goto out_buf; } newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]); + if (newblk < QT_TREEOFF || newblk >= info->dqi_blocks) { + quota_error(dquot->dq_sb, "Getting block too big (%u >= %u)", + newblk, info->dqi_blocks); + ret = -EUCLEAN; + goto out_buf; + } + if (depth == info->dqi_qtree_depth - 1) { ret = free_dqentry(info, dquot, newblk); newblk = 0; @@ -587,6 +594,13 @@ static loff_t find_tree_dqentry(struct qtree_mem_dqinfo *info, blk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]); if (!blk) /* No reference? */ goto out_buf; + if (blk < QT_TREEOFF || blk >= info->dqi_blocks) { + quota_error(dquot->dq_sb, "Getting block too big (%u >= %u)", + blk, info->dqi_blocks); + ret = -EUCLEAN; + goto out_buf; + } + if (depth < info->dqi_qtree_depth - 1) ret = find_tree_dqentry(info, dquot, blk, depth+1); else -- Gitee