From: Danilo Krummrich <dakr@kernel.org> stable inclusion from stable-v6.12.80 commit 9a6086d2a828dd2ff74cf9abcae456670febd71f category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/14259 CVE: CVE-2026-31527 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 2b38efc05bf7a8568ec74bfffea0f5cfa62bc01d ] 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: 3d713e0e382e ("driver core: platform: add device binding path 'driver_override'") Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://patch.msgid.link/20260303115720.48783-5-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Conflicts: drivers/base/platform.c drivers/slimbus/qcom-ngd-ctrl.c include/linux/platform_device.h drivers/clk/imx/clk-scu.c sound/soc/samsung/i2s.c drivers/bus/simple-pm-bus.c drivers/slimbus/qcom-ngd-ctrl.c [Context Conflicts] Signed-off-by: Lin Ruifeng <linruifeng4@huawei.com> --- drivers/base/platform.c | 57 +++------------------------------ drivers/slimbus/qcom-ngd-ctrl.c | 12 ++++++- include/linux/platform_device.h | 1 - 3 files changed, 16 insertions(+), 54 deletions(-) diff --git a/drivers/base/platform.c b/drivers/base/platform.c index e332579744fb..4a2e15e74a06 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -268,7 +268,6 @@ static void platform_device_release(struct device *dev) kfree(pa->pdev.dev.platform_data); kfree(pa->pdev.mfd_cell); kfree(pa->pdev.resource); - kfree(pa->pdev.driver_override); kfree(pa); } @@ -882,57 +881,8 @@ static ssize_t modalias_show(struct device *dev, } static DEVICE_ATTR_RO(modalias); -static ssize_t driver_override_store(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t count) -{ - struct platform_device *pdev = to_platform_device(dev); - char *driver_override, *old, *cp; - - /* We need to keep extra room for a newline */ - if (count >= (PAGE_SIZE - 1)) - return -EINVAL; - - driver_override = kstrndup(buf, count, GFP_KERNEL); - if (!driver_override) - return -ENOMEM; - - cp = strchr(driver_override, '\n'); - if (cp) - *cp = '\0'; - - device_lock(dev); - old = pdev->driver_override; - if (strlen(driver_override)) { - pdev->driver_override = driver_override; - } else { - kfree(driver_override); - pdev->driver_override = NULL; - } - device_unlock(dev); - - kfree(old); - - return count; -} - -static ssize_t driver_override_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct platform_device *pdev = to_platform_device(dev); - ssize_t len; - - device_lock(dev); - len = sysfs_emit(buf, "%s\n", pdev->driver_override); - device_unlock(dev); - return len; -} -static DEVICE_ATTR_RW(driver_override); - - static struct attribute *platform_dev_attrs[] = { &dev_attr_modalias.attr, - &dev_attr_driver_override.attr, NULL, }; ATTRIBUTE_GROUPS(platform_dev); @@ -987,10 +937,12 @@ static int platform_match(struct device *dev, struct device_driver *drv) { struct platform_device *pdev = to_platform_device(dev); struct platform_driver *pdrv = to_platform_driver(drv); + int ret; /* When driver_override is set, only bind to the matching driver */ - if (pdev->driver_override) - return !strcmp(pdev->driver_override, drv->name); + ret = device_match_driver_override(dev, drv); + if (ret >= 0) + return ret; /* Attempt an OF style match first */ if (of_driver_match_device(dev, drv)) @@ -1177,6 +1129,7 @@ static const struct dev_pm_ops platform_dev_pm_ops = { struct bus_type platform_bus_type = { .name = "platform", .dev_groups = platform_dev_groups, + .driver_override = true, .match = platform_match, .uevent = platform_uevent, .dma_configure = platform_dma_configure, diff --git a/drivers/slimbus/qcom-ngd-ctrl.c b/drivers/slimbus/qcom-ngd-ctrl.c index 9221ba7b7863..6d2c0d2f5696 100644 --- a/drivers/slimbus/qcom-ngd-ctrl.c +++ b/drivers/slimbus/qcom-ngd-ctrl.c @@ -1329,6 +1329,7 @@ static int of_qcom_slim_ngd_register(struct device *parent, const struct of_device_id *match; struct device_node *node; u32 id; + int ret; match = of_match_node(qcom_slim_ngd_dt_match, parent->of_node); data = match->data; @@ -1345,9 +1346,18 @@ static int of_qcom_slim_ngd_register(struct device *parent, kfree(ngd); return -ENOMEM; } + + ret = device_set_driver_override(&ngd->pdev->dev, + QCOM_SLIM_NGD_DRV_NAME); + if (ret) { + platform_device_put(ngd->pdev); + kfree(ngd); + of_node_put(node); + return ret; + } + ngd->id = id; ngd->pdev->dev.parent = parent; - ngd->pdev->driver_override = QCOM_SLIM_NGD_DRV_NAME; ngd->pdev->dev.of_node = node; ctrl->ngd = ngd; platform_set_drvdata(ngd->pdev, ctrl); diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h index 9e5c98fcea8c..eef1e77eb43b 100644 --- a/include/linux/platform_device.h +++ b/include/linux/platform_device.h @@ -29,7 +29,6 @@ struct platform_device { struct resource *resource; const struct platform_device_id *id_entry; - char *driver_override; /* Driver name to force a match */ /* MFD cell pointer */ struct mfd_cell *mfd_cell; -- 2.43.0