From: Danilo Krummrich <dakr@kernel.org> stable inclusion from stable-v6.18.33 commit 654ef9c33e138ede6734ac286282df9faf83cd11 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/15815 CVE: CVE-2026-53118 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 85bb534ff12aab6916058897b39c748940a7a4c6 ] When a driver is probed through __driver_attach(), the bus' match() callback is called without the device lock held, thus accessing the driver_override field without a lock, which can cause a UAF. Fix this by using the driver-core driver_override infrastructure taking care of proper locking internally. Note that calling match() from __driver_attach() without the device lock held is intentional. [1] Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [1] Reported-by: Gui-Dong Han <hanguidong02@gmail.com> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789 Fixes: 539fec78edb4 ("vdpa: add driver_override support") Acked-by: Eugenio Pérez <eperezma@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Link: https://patch.msgid.link/20260324005919.2408620-9-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Conflicts: drivers/vdpa/vdpa.c include/linux/vdpa.h [Context Conflicts] Signed-off-by: Lin Ruifeng <linruifeng4@huawei.com> --- drivers/vdpa/vdpa.c | 48 +++++--------------------------------------- include/linux/vdpa.h | 4 ---- 2 files changed, 5 insertions(+), 47 deletions(-) diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c index a7612e0783b3..28a2fb1d0fa4 100644 --- a/drivers/vdpa/vdpa.c +++ b/drivers/vdpa/vdpa.c @@ -67,57 +67,20 @@ static void vdpa_dev_remove(struct device *d) static int vdpa_dev_match(struct device *dev, struct device_driver *drv) { - struct vdpa_device *vdev = dev_to_vdpa(dev); + int ret; /* Check override first, and if set, only use the named driver */ - if (vdev->driver_override) - return strcmp(vdev->driver_override, drv->name) == 0; + ret = device_match_driver_override(dev, drv); + if (ret >= 0) + return ret; /* Currently devices must be supported by all vDPA bus drivers */ return 1; } -static ssize_t driver_override_store(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t count) -{ - struct vdpa_device *vdev = dev_to_vdpa(dev); - int ret; - - ret = driver_set_override(dev, &vdev->driver_override, buf, count); - if (ret) - return ret; - - return count; -} - -static ssize_t driver_override_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct vdpa_device *vdev = dev_to_vdpa(dev); - ssize_t len; - - device_lock(dev); - len = snprintf(buf, PAGE_SIZE, "%s\n", vdev->driver_override); - device_unlock(dev); - - return len; -} -static DEVICE_ATTR_RW(driver_override); - -static struct attribute *vdpa_dev_attrs[] = { - &dev_attr_driver_override.attr, - NULL, -}; - -static const struct attribute_group vdpa_dev_group = { - .attrs = vdpa_dev_attrs, -}; -__ATTRIBUTE_GROUPS(vdpa_dev); - static struct bus_type vdpa_bus = { .name = "vdpa", - .dev_groups = vdpa_dev_groups, + .driver_override = true, .match = vdpa_dev_match, .probe = vdpa_dev_probe, .remove = vdpa_dev_remove, @@ -132,7 +95,6 @@ static void vdpa_release_dev(struct device *d) ops->free(vdev); ida_simple_remove(&vdpa_index_ida, vdev->index); - kfree(vdev->driver_override); kfree(vdev); } diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h index 3120a1a600dd..f16a2647e1cc 100644 --- a/include/linux/vdpa.h +++ b/include/linux/vdpa.h @@ -70,9 +70,6 @@ struct vdpa_mgmt_dev; * struct vdpa_device - representation of a vDPA device * @dev: underlying device * @dma_dev: the actual device that is performing DMA - * @driver_override: driver name to force a match; do not set directly, - * because core frees it; use driver_set_override() to - * set or clear it. * @config: the configuration ops for this device. * @cf_lock: Protects get and set access to configuration layout. * @index: device index @@ -87,7 +84,6 @@ struct vdpa_mgmt_dev; struct vdpa_device { struct device dev; struct device *dma_dev; - const char *driver_override; const struct vdpa_config_ops *config; struct rw_semaphore cf_lock; /* Protects get/set config */ unsigned int index; -- 2.34.1