From eb4a328c89064fedc45f48d0b2cd6dd60a634df4 Mon Sep 17 00:00:00 2001
From: gullradriel <gullradriel@users.noreply.github.com>
Date: Thu, 12 Feb 2026 11:47:27 +0100
Subject: [PATCH] do not free/realloc furi_string as flipper_format_read_string
 is doing a reset of the string, check for problems and return error

---
 protocols/fiat_v0.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/protocols/fiat_v0.c b/protocols/fiat_v0.c
index f259ae5..7e4ea86 100644
--- a/protocols/fiat_v0.c
+++ b/protocols/fiat_v0.c
@@ -226,18 +226,20 @@ SubGhzProtocolStatus
 
     do {
         FuriString* temp_str = furi_string_alloc();
+        furi_check(temp_str);
         if(!flipper_format_read_string(flipper_format, "Protocol", temp_str)) {
             FURI_LOG_E(TAG, "Missing Protocol");
             furi_string_free(temp_str);
+            temp_str = NULL;
             break;
         }
 
         if(!furi_string_equal(temp_str, instance->base.protocol->name)) {
             FURI_LOG_E(TAG, "Wrong protocol: %s", furi_string_get_cstr(temp_str));
             furi_string_free(temp_str);
+            temp_str = NULL;
             break;
         }
-        furi_string_free(temp_str);
 
         uint32_t bit_count_temp;
         if(!flipper_format_read_uint32(flipper_format, "Bit", &bit_count_temp, 1)) {
@@ -245,13 +247,18 @@ SubGhzProtocolStatus
             break;
         }
 
-        temp_str = furi_string_alloc();
         if(!flipper_format_read_string(flipper_format, "Key", temp_str)) {
             FURI_LOG_E(TAG, "Missing Key");
             furi_string_free(temp_str);
+            temp_str = NULL;
             break;
         }
 
+        // if no string to decode return error
+        if(!temp_str) {
+            return ret;
+        }
+
         const char* key_str = furi_string_get_cstr(temp_str);
         uint64_t key = 0;
         size_t str_len = strlen(key_str);