From 0d67e0fa1664ad6aaba0552e170608bafb4b6196 Mon Sep 17 00:00:00 2001 From: Heikki Krogerus Date: Thu, 10 Mar 2016 13:03:18 +0200 Subject: [PATCH] device property: fix for a case of use-after-free In device_remove_property_set(), the secondary fwnode needs to be cleared before the pset is freed. This fixes a use-after-free when a property set is providing the primary fwnode. As a result of the fix, the primary fwnode may end up containing ERR_PTR(-ENODEV), so also adding checks for it to the property handling code. Reported-by: John Youn Signed-off-by: Heikki Krogerus Signed-off-by: Rafael J. Wysocki --- drivers/base/property.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) diff --git a/drivers/base/property.c b/drivers/base/property.c index a163f2c59aa3..76628a7b45f1 100644 --- a/drivers/base/property.c +++ b/drivers/base/property.c @@ -218,7 +218,8 @@ bool fwnode_property_present(struct fwnode_handle *fwnode, const char *propname) bool ret; ret = __fwnode_property_present(fwnode, propname); - if (ret == false && fwnode && !IS_ERR_OR_NULL(fwnode->secondary)) + if (ret == false && !IS_ERR_OR_NULL(fwnode) && + !IS_ERR_OR_NULL(fwnode->secondary)) ret = __fwnode_property_present(fwnode->secondary, propname); return ret; } @@ -423,7 +424,8 @@ EXPORT_SYMBOL_GPL(device_property_match_string); int _ret_; \ _ret_ = FWNODE_PROP_READ(_fwnode_, _propname_, _type_, _proptype_, \ _val_, _nval_); \ - if (_ret_ == -EINVAL && _fwnode_ && !IS_ERR_OR_NULL(_fwnode_->secondary)) \ + if (_ret_ == -EINVAL && !IS_ERR_OR_NULL(_fwnode_) && \ + !IS_ERR_OR_NULL(_fwnode_->secondary)) \ _ret_ = FWNODE_PROP_READ(_fwnode_->secondary, _propname_, _type_, \ _proptype_, _val_, _nval_); \ _ret_; \ @@ -593,7 +595,8 @@ int fwnode_property_read_string_array(struct fwnode_handle *fwnode, int ret; ret = __fwnode_property_read_string_array(fwnode, propname, val, nval); - if (ret == -EINVAL && fwnode && !IS_ERR_OR_NULL(fwnode->secondary)) + if (ret == -EINVAL && !IS_ERR_OR_NULL(fwnode) && + !IS_ERR_OR_NULL(fwnode->secondary)) ret = __fwnode_property_read_string_array(fwnode->secondary, propname, val, nval); return ret; @@ -621,7 +624,8 @@ int fwnode_property_read_string(struct fwnode_handle *fwnode, int ret; ret = __fwnode_property_read_string(fwnode, propname, val); - if (ret == -EINVAL && fwnode && !IS_ERR_OR_NULL(fwnode->secondary)) + if (ret == -EINVAL && !IS_ERR_OR_NULL(fwnode) && + !IS_ERR_OR_NULL(fwnode->secondary)) ret = __fwnode_property_read_string(fwnode->secondary, propname, val); return ret; @@ -820,11 +824,16 @@ void device_remove_property_set(struct device *dev) * the pset. If there is no real firmware node (ACPI/DT) primary * will hold the pset. */ - if (!is_pset_node(fwnode)) - fwnode = fwnode->secondary; - if (!IS_ERR(fwnode) && is_pset_node(fwnode)) + if (is_pset_node(fwnode)) { + set_primary_fwnode(dev, NULL); pset_free_set(to_pset_node(fwnode)); - set_secondary_fwnode(dev, NULL); + } else { + fwnode = fwnode->secondary; + if (!IS_ERR(fwnode) && is_pset_node(fwnode)) { + set_secondary_fwnode(dev, NULL); + pset_free_set(to_pset_node(fwnode)); + } + } } EXPORT_SYMBOL_GPL(device_remove_property_set);