1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Module taint unload tracking support 4 * 5 * Copyright (C) 2022 Aaron Tomlin 6 */ 7 8 #include <linux/module.h> 9 #include <linux/string.h> 10 #include <linux/printk.h> 11 #include <linux/slab.h> 12 #include <linux/list.h> 13 #include <linux/rculist.h> 14 #include "internal.h" 15 16 static LIST_HEAD(unloaded_tainted_modules); 17 18 int try_add_tainted_module(struct module *mod) 19 { 20 struct mod_unload_taint *mod_taint; 21 22 module_assert_mutex_or_preempt(); 23 24 list_for_each_entry_rcu(mod_taint, &unloaded_tainted_modules, list, 25 lockdep_is_held(&module_mutex)) { 26 if (!strcmp(mod_taint->name, mod->name) && 27 mod_taint->taints & mod->taints) { 28 mod_taint->count++; 29 goto out; 30 } 31 } 32 33 mod_taint = kmalloc(sizeof(*mod_taint), GFP_KERNEL); 34 if (unlikely(!mod_taint)) 35 return -ENOMEM; 36 strscpy(mod_taint->name, mod->name, MODULE_NAME_LEN); 37 mod_taint->taints = mod->taints; 38 list_add_rcu(&mod_taint->list, &unloaded_tainted_modules); 39 mod_taint->count = 1; 40 out: 41 return 0; 42 } 43 44 void print_unloaded_tainted_modules(void) 45 { 46 struct mod_unload_taint *mod_taint; 47 char buf[MODULE_FLAGS_BUF_SIZE]; 48 49 if (!list_empty(&unloaded_tainted_modules)) { 50 printk(KERN_DEFAULT "Unloaded tainted modules:"); 51 list_for_each_entry_rcu(mod_taint, &unloaded_tainted_modules, 52 list) { 53 size_t l; 54 55 l = module_flags_taint(mod_taint->taints, buf); 56 buf[l++] = '\0'; 57 pr_cont(" %s(%s):%llu", mod_taint->name, buf, 58 mod_taint->count); 59 } 60 } 61 } 62