[Intel-wired-lan] [PATCH iwl-net] ice: fix integer overflow in ice_get_pfa_module_tlv

[Jacob Keller]

From: Paul Greenwalt <paul.greenwalt at intel.com>

It's possible that an NVM with an invalid tlv_len could cause an integer
overflow of next_tlv which can result an infinite loop.

Fix this issue by changing next_tlv from u16 to u32 to prevent overflow.
Also check that tlv_len is valid and less than pfa_len.

Signed-off-by: Paul Greenwalt <paul.greenwalt at intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller at intel.com>
---
 drivers/net/ethernet/intel/ice/ice_nvm.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_nvm.c b/drivers/net/ethernet/intel/ice/ice_nvm.c
index 84eab92dc03c..9e58d319355f 100644
--- a/drivers/net/ethernet/intel/ice/ice_nvm.c
+++ b/drivers/net/ethernet/intel/ice/ice_nvm.c
@@ -441,7 +441,7 @@ ice_get_pfa_module_tlv(struct ice_hw *hw, u16 *module_tlv, u16 *module_tlv_len,
 		       u16 module_type)
 {
 	u16 pfa_len, pfa_ptr;
-	u16 next_tlv;
+	u32 next_tlv;
 	int status;
 
 	status = ice_read_sr_word(hw, ICE_SR_PFA_PTR, &pfa_ptr);
@@ -458,7 +458,7 @@ ice_get_pfa_module_tlv(struct ice_hw *hw, u16 *module_tlv, u16 *module_tlv_len,
 	 * of TLVs to find the requested one.
 	 */
 	next_tlv = pfa_ptr + 1;
-	while (next_tlv < pfa_ptr + pfa_len) {
+	while (next_tlv < ((u32)pfa_ptr + pfa_len)) {
 		u16 tlv_sub_module_type;
 		u16 tlv_len;
 
@@ -474,6 +474,10 @@ ice_get_pfa_module_tlv(struct ice_hw *hw, u16 *module_tlv, u16 *module_tlv_len,
 			ice_debug(hw, ICE_DBG_INIT, "Failed to read TLV length.\n");
 			break;
 		}
+		if (tlv_len > pfa_len) {
+			ice_debug(hw, ICE_DBG_INIT, "Invalid TLV length.\n");
+			return -EINVAL;
+		}
 		if (tlv_sub_module_type == module_type) {
 			if (tlv_len) {
 				*module_tlv = next_tlv;

---
base-commit: 83e93942796db58652288f0391ac00072401816f
change-id: 20240516-iwl-net-2024-05-16-fix-nvm-tlv-issue-99ebb2c55c52

Best regards,
-- 
Jacob Keller <jacob.e.keller at intel.com>