iwlwifi: mvm: check for n_profiles validity in EWRD ACPI

[ Upstream commit 2e1976bb75263fbad918e82184b16a23bd721546 ] When reading the profiles from the EWRD table in ACPI, we loop over the data and set it into our internal table. We use the number of profiles specified in ACPI without checking its validity, so if the ACPI table is corrupted and the number is larger than our array size, we will try to make an out-of-bounds access. Fix this by making sure the value specified in the ACPI table is valid. Fixes: 6996490 ("iwlwifi: mvm: add support for EWRD (Dynamic SAR) ACPI table") Signed-off-by: Luca Coelho <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
akeromi · Nov 13, 2018 · a2abae5 · a2abae5
1 parent b325d55
commit a2abae5
Showing 1 changed file with 6 additions and 2 deletions.
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/fw.c b/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
@@ -704,8 +704,12 @@ static int iwl_mvm_sar_get_ewrd_table(struct iwl_mvm *mvm)
 	enabled = !!(wifi_pkg->package.elements[1].integer.value);
 	n_profiles = wifi_pkg->package.elements[2].integer.value;
 
-	/* in case of BIOS bug */
-	if (n_profiles <= 0) {
+	/*
+	 * Check the validity of n_profiles.  The EWRD profiles start
+	 * from index 1, so the maximum value allowed here is
+	 * ACPI_SAR_PROFILES_NUM - 1.
+	 */
+	if (n_profiles <= 0 || n_profiles >= ACPI_SAR_PROFILE_NUM) {
 		ret = -EINVAL;
 		goto out_free;
 	}