nrf_compress: lzma: Workaround oddities with LZMA library

The LZMA library believes that free() should be called with an
address of NULL, this is completely invalid, therefore ignore
any attempt to free memory at this address

Signed-off-by: Jamie McCrae <[email protected]>

Author: nordicjm

subsys/nrf_compress/src/lzma.c

@@ -56,11 +56,11 @@ static void *lzma_probs_alloc(ISzAllocPtr p, size_t size)
 
 	if (buffer == NULL) {
 		LOG_ERR("Failed to allocate nRF compression library buffer (0x%x)", size);
-	}
-
 #ifdef CONFIG_NRF_COMPRESS_CLEANUP
-	malloc_probs_size = size;
+	} else {
+		malloc_probs_size = size;
 #endif
+	}
 
 	return buffer;
 #endif
@@ -84,9 +84,15 @@ static void lzma_probs_free(ISzAllocPtr p, void *address)
 {
 #if defined(CONFIG_NRF_COMPRESS_MEMORY_TYPE_MALLOC)
 #ifdef CONFIG_NRF_COMPRESS_CLEANUP
-	like_mbedtls_zeroize(address, malloc_probs_size);
+	if (address == NULL) {
+		return;
+	}
+
+	if (malloc_probs_size > 0) {
+		like_mbedtls_zeroize(address, malloc_probs_size);
+		malloc_probs_size = 0;
+	}
 
-	malloc_probs_size = 0;
 #endif
 	free(address);
 #else