From: Johannes Berg <johannes.berg@xxxxxxxxx>
If the firmware sends us a corrupted MCC response with
n_channels much larger than the command response can be,
we might copy far too much (uninitialized) memory and
even crash if the n_channels is large enough to make it
run out of the one page allocated for the FW response.
Fix that by checking the lengths. Doing a < comparison
would be sufficient, but the firmware should be doing
it correctly, so check more strictly.
Fixes: dcaf9f5ecb6f ("iwlwifi: mvm: add MCC update FW API")
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Gregory Greenman <gregory.greenman@xxxxxxxxx>
---
drivers/net/wireless/intel/iwlwifi/mvm/nvm.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/nvm.c b/drivers/net/wireless/intel/iwlwifi/mvm/nvm.c
index 6d18a1fd649b..fdf60afb0f3f 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/nvm.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/nvm.c
@@ -445,6 +445,11 @@ iwl_mvm_update_mcc(struct iwl_mvm *mvm, const char *alpha2,
struct iwl_mcc_update_resp *mcc_resp = (void *)pkt->data;
n_channels = __le32_to_cpu(mcc_resp->n_channels);
+ if (iwl_rx_packet_payload_len(pkt) !=
+ struct_size(mcc_resp, channels, n_channels)) {
+ resp_cp = ERR_PTR(-EINVAL);
+ goto exit;
+ }
resp_len = sizeof(struct iwl_mcc_update_resp) +
n_channels * sizeof(__le32);
resp_cp = kmemdup(mcc_resp, resp_len, GFP_KERNEL);
@@ -456,6 +461,11 @@ iwl_mvm_update_mcc(struct iwl_mvm *mvm, const char *alpha2,
struct iwl_mcc_update_resp_v3 *mcc_resp_v3 = (void *)pkt->data;
n_channels = __le32_to_cpu(mcc_resp_v3->n_channels);
+ if (iwl_rx_packet_payload_len(pkt) !=
+ struct_size(mcc_resp_v3, channels, n_channels)) {
+ resp_cp = ERR_PTR(-EINVAL);
+ goto exit;
+ }
resp_len = sizeof(struct iwl_mcc_update_resp) +
n_channels * sizeof(__le32);
resp_cp = kzalloc(resp_len, GFP_KERNEL);
--
2.38.1
