@@ -480,15 +480,22 @@ struct ahci_host_priv *ahci_platform_get_resources(struct platform_device *pdev,
}
}
- hpriv->nports = child_nodes = of_get_child_count(dev->of_node);
+ /*
+ * Too many sub-nodes most likely means having something wrong with
+ * the firmware.
+ */
+ child_nodes = of_get_child_count(dev->of_node);
+ if (child_nodes > AHCI_MAX_PORTS) {
+ rc = -EINVAL;
+ goto err_out;
+ }
/*
* If no sub-node was found, we still need to set nports to
* one in order to be able to use the
* ahci_platform_[en|dis]able_[phys|regulators] functions.
*/
- if (!child_nodes)
- hpriv->nports = 1;
+ hpriv->nports = child_nodes ?: 1;
hpriv->phys = devm_kcalloc(dev, hpriv->nports, sizeof(*hpriv->phys), GFP_KERNEL);
if (!hpriv->phys) {
Having greater than (AHCI_MAX_PORTS = 32) ports detected isn't that critical from the further AHCI-platform initialization point of view since exceeding the ports upper limit will cause allocating more resources than will be used afterwards. But detecting too many child DT-nodes doesn't seem right since it's very unlikely to have it on an ordinary platform. In accordance with the AHCI specification there can't be more than 32 ports implemented at least due to having the CAP.NP field of 4 bits wide and the PI register of dword size. Thus if such situation is found the DTB must have been corrupted and the data read from it shouldn't be reliable. Let's consider that as an erroneous situation and halt further resources allocation. Note it's logically more correct to have the nports set only after the initialization value is checked for being sane. So while at it let's make sure nports is assigned with a correct value. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> --- Changelog v2: - Drop the else word from the child_nodes value checking if-else-if statement (@Damien) and convert the after-else part into the ternary operator-based statement. --- drivers/ata/libahci_platform.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)