ACPI: thinkpad-acpi: don't misdetect in get_thinkpad_model_data() on -ENOMEM

Explicitly check for memory allocation failures, and return status to
indicate that we could not collect data due to errors.

This lets the driver have a far more predictable failure mode on ENOMEM in
that codepath: it will refuse to load.  This is far better than trying to
proceed with missing data which is used to detect quirks, etc.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>

1 files changed, 33 insertions, 14 deletions

diff --git a/drivers/misc/thinkpad_acpi.c b/drivers/misc/thinkpad_acpi.c
index 3eb01afe4306..d3eb7903c346 100644
--- a/drivers/misc/thinkpad_acpi.c
+++ b/drivers/misc/thinkpad_acpi.c
@@ -6340,13 +6340,18 @@ err_out:
 
 /* Probing */
 
-static void __init get_thinkpad_model_data(struct thinkpad_id_data *tp)
+/* returns 0 - probe ok, or < 0 - probe error.
+ * Probe ok doesn't mean thinkpad found.
+ * On error, kfree() cleanup on tp->* is not performed, caller must do it */
+static int __must_check __init get_thinkpad_model_data(
+                                                struct thinkpad_id_data *tp)
 {
         const struct dmi_device *dev = NULL;
         char ec_fw_string[18];
+        char const *s;
 
         if (!tp)
-                return;
+                return -EINVAL;
 
         memset(tp, 0, sizeof(*tp));
 
@@ -6355,12 +6360,14 @@ static void __init get_thinkpad_model_data(struct thinkpad_id_data *tp)
         else if (dmi_name_in_vendors("LENOVO"))
                 tp->vendor = PCI_VENDOR_ID_LENOVO;
         else
-                return;
+                return 0;
 
-        tp->bios_version_str = kstrdup(dmi_get_system_info(DMI_BIOS_VERSION),
-                                        GFP_KERNEL);
+        s = dmi_get_system_info(DMI_BIOS_VERSION);
+        tp->bios_version_str = kstrdup(s, GFP_KERNEL);
+        if (s && !tp->bios_version_str)
+                return -ENOMEM;
         if (!tp->bios_version_str)
-                return;
+                return 0;
         tp->bios_model = tp->bios_version_str[0]
                          | (tp->bios_version_str[1] << 8);
 
@@ -6379,21 +6386,27 @@ static void __init get_thinkpad_model_data(struct thinkpad_id_data *tp)
                         ec_fw_string[strcspn(ec_fw_string, " ]")] = 0;
 
                         tp->ec_version_str = kstrdup(ec_fw_string, GFP_KERNEL);
+                        if (!tp->ec_version_str)
+                                return -ENOMEM;
                         tp->ec_model = ec_fw_string[0]
                                         | (ec_fw_string[1] << 8);
                         break;
                 }
         }
 
-        tp->model_str = kstrdup(dmi_get_system_info(DMI_PRODUCT_VERSION),
-                                        GFP_KERNEL);
-        if (tp->model_str && strnicmp(tp->model_str, "ThinkPad", 8) != 0) {
-                kfree(tp->model_str);
-                tp->model_str = NULL;
+        s = dmi_get_system_info(DMI_PRODUCT_VERSION);
+        if (s && !strnicmp(s, "ThinkPad", 8)) {
+                tp->model_str = kstrdup(s, GFP_KERNEL);
+                if (!tp->model_str)
+                        return -ENOMEM;
         }
 
-        tp->nummodel_str = kstrdup(dmi_get_system_info(DMI_PRODUCT_NAME),
-                                        GFP_KERNEL);
+        s = dmi_get_system_info(DMI_PRODUCT_NAME);
+        tp->nummodel_str = kstrdup(s, GFP_KERNEL);
+        if (s && !tp->nummodel_str)
+                return -ENOMEM;
+
+        return 0;
 }
 
 static int __init probe_for_thinkpad(void)
@@ -6656,7 +6669,13 @@ static int __init thinkpad_acpi_module_init(void)
 
         /* Driver-level probe */
 
-        get_thinkpad_model_data(&thinkpad_id);
+        ret = get_thinkpad_model_data(&thinkpad_id);
+        if (ret) {
+                printk(TPACPI_ERR
+                        "unable to get DMI data: %d\n", ret);
+                thinkpad_acpi_module_exit();
+                return ret;
+        }
         ret = probe_for_thinkpad();
         if (ret) {
                 thinkpad_acpi_module_exit();