199bd9956SAaron Tomlin // SPDX-License-Identifier: GPL-2.0-or-later 299bd9956SAaron Tomlin /* 399bd9956SAaron Tomlin * Module taint unload tracking support 499bd9956SAaron Tomlin * 599bd9956SAaron Tomlin * Copyright (C) 2022 Aaron Tomlin 699bd9956SAaron Tomlin */ 799bd9956SAaron Tomlin 899bd9956SAaron Tomlin #include <linux/module.h> 999bd9956SAaron Tomlin #include <linux/string.h> 1099bd9956SAaron Tomlin #include <linux/printk.h> 1199bd9956SAaron Tomlin #include <linux/slab.h> 1299bd9956SAaron Tomlin #include <linux/list.h> 13beef988cSAaron Tomlin #include <linux/debugfs.h> 1499bd9956SAaron Tomlin #include <linux/rculist.h> 1599bd9956SAaron Tomlin #include "internal.h" 1699bd9956SAaron Tomlin 1799bd9956SAaron Tomlin static LIST_HEAD(unloaded_tainted_modules); 1899bd9956SAaron Tomlin 1999bd9956SAaron Tomlin int try_add_tainted_module(struct module *mod) 2099bd9956SAaron Tomlin { 2199bd9956SAaron Tomlin struct mod_unload_taint *mod_taint; 2299bd9956SAaron Tomlin 2399bd9956SAaron Tomlin module_assert_mutex_or_preempt(); 2499bd9956SAaron Tomlin 25*47cc75aaSAaron Tomlin if (!mod->taints) 26*47cc75aaSAaron Tomlin goto out; 27*47cc75aaSAaron Tomlin 2899bd9956SAaron Tomlin list_for_each_entry_rcu(mod_taint, &unloaded_tainted_modules, list, 2999bd9956SAaron Tomlin lockdep_is_held(&module_mutex)) { 3099bd9956SAaron Tomlin if (!strcmp(mod_taint->name, mod->name) && 3199bd9956SAaron Tomlin mod_taint->taints & mod->taints) { 3299bd9956SAaron Tomlin mod_taint->count++; 3399bd9956SAaron Tomlin goto out; 3499bd9956SAaron Tomlin } 3599bd9956SAaron Tomlin } 3699bd9956SAaron Tomlin 3799bd9956SAaron Tomlin mod_taint = kmalloc(sizeof(*mod_taint), GFP_KERNEL); 3899bd9956SAaron Tomlin if (unlikely(!mod_taint)) 3999bd9956SAaron Tomlin return -ENOMEM; 4099bd9956SAaron Tomlin strscpy(mod_taint->name, mod->name, MODULE_NAME_LEN); 4199bd9956SAaron Tomlin mod_taint->taints = mod->taints; 4299bd9956SAaron Tomlin list_add_rcu(&mod_taint->list, &unloaded_tainted_modules); 4399bd9956SAaron Tomlin mod_taint->count = 1; 4499bd9956SAaron Tomlin out: 4599bd9956SAaron Tomlin return 0; 4699bd9956SAaron Tomlin } 4799bd9956SAaron Tomlin 4899bd9956SAaron Tomlin void print_unloaded_tainted_modules(void) 4999bd9956SAaron Tomlin { 5099bd9956SAaron Tomlin struct mod_unload_taint *mod_taint; 5199bd9956SAaron Tomlin char buf[MODULE_FLAGS_BUF_SIZE]; 5299bd9956SAaron Tomlin 5399bd9956SAaron Tomlin if (!list_empty(&unloaded_tainted_modules)) { 5499bd9956SAaron Tomlin printk(KERN_DEFAULT "Unloaded tainted modules:"); 5599bd9956SAaron Tomlin list_for_each_entry_rcu(mod_taint, &unloaded_tainted_modules, 5699bd9956SAaron Tomlin list) { 5799bd9956SAaron Tomlin size_t l; 5899bd9956SAaron Tomlin 5999bd9956SAaron Tomlin l = module_flags_taint(mod_taint->taints, buf); 6099bd9956SAaron Tomlin buf[l++] = '\0'; 6199bd9956SAaron Tomlin pr_cont(" %s(%s):%llu", mod_taint->name, buf, 6299bd9956SAaron Tomlin mod_taint->count); 6399bd9956SAaron Tomlin } 6499bd9956SAaron Tomlin } 6599bd9956SAaron Tomlin } 66beef988cSAaron Tomlin 67beef988cSAaron Tomlin #ifdef CONFIG_DEBUG_FS 68beef988cSAaron Tomlin static void *unloaded_tainted_modules_seq_start(struct seq_file *m, loff_t *pos) 69beef988cSAaron Tomlin __acquires(rcu) 70beef988cSAaron Tomlin { 71beef988cSAaron Tomlin rcu_read_lock(); 72beef988cSAaron Tomlin return seq_list_start_rcu(&unloaded_tainted_modules, *pos); 73beef988cSAaron Tomlin } 74beef988cSAaron Tomlin 75beef988cSAaron Tomlin static void *unloaded_tainted_modules_seq_next(struct seq_file *m, void *p, loff_t *pos) 76beef988cSAaron Tomlin { 77beef988cSAaron Tomlin return seq_list_next_rcu(p, &unloaded_tainted_modules, pos); 78beef988cSAaron Tomlin } 79beef988cSAaron Tomlin 80beef988cSAaron Tomlin static void unloaded_tainted_modules_seq_stop(struct seq_file *m, void *p) 81beef988cSAaron Tomlin __releases(rcu) 82beef988cSAaron Tomlin { 83beef988cSAaron Tomlin rcu_read_unlock(); 84beef988cSAaron Tomlin } 85beef988cSAaron Tomlin 86beef988cSAaron Tomlin static int unloaded_tainted_modules_seq_show(struct seq_file *m, void *p) 87beef988cSAaron Tomlin { 88beef988cSAaron Tomlin struct mod_unload_taint *mod_taint; 89beef988cSAaron Tomlin char buf[MODULE_FLAGS_BUF_SIZE]; 90beef988cSAaron Tomlin size_t l; 91beef988cSAaron Tomlin 92beef988cSAaron Tomlin mod_taint = list_entry(p, struct mod_unload_taint, list); 93beef988cSAaron Tomlin l = module_flags_taint(mod_taint->taints, buf); 94beef988cSAaron Tomlin buf[l++] = '\0'; 95beef988cSAaron Tomlin 96beef988cSAaron Tomlin seq_printf(m, "%s (%s) %llu", mod_taint->name, buf, mod_taint->count); 97beef988cSAaron Tomlin seq_puts(m, "\n"); 98beef988cSAaron Tomlin 99beef988cSAaron Tomlin return 0; 100beef988cSAaron Tomlin } 101beef988cSAaron Tomlin 102beef988cSAaron Tomlin static const struct seq_operations unloaded_tainted_modules_seq_ops = { 103beef988cSAaron Tomlin .start = unloaded_tainted_modules_seq_start, 104beef988cSAaron Tomlin .next = unloaded_tainted_modules_seq_next, 105beef988cSAaron Tomlin .stop = unloaded_tainted_modules_seq_stop, 106beef988cSAaron Tomlin .show = unloaded_tainted_modules_seq_show, 107beef988cSAaron Tomlin }; 108beef988cSAaron Tomlin 109beef988cSAaron Tomlin static int unloaded_tainted_modules_open(struct inode *inode, struct file *file) 110beef988cSAaron Tomlin { 111beef988cSAaron Tomlin return seq_open(file, &unloaded_tainted_modules_seq_ops); 112beef988cSAaron Tomlin } 113beef988cSAaron Tomlin 114beef988cSAaron Tomlin static const struct file_operations unloaded_tainted_modules_fops = { 115beef988cSAaron Tomlin .open = unloaded_tainted_modules_open, 116beef988cSAaron Tomlin .read = seq_read, 117beef988cSAaron Tomlin .llseek = seq_lseek, 118beef988cSAaron Tomlin .release = seq_release, 119beef988cSAaron Tomlin }; 120beef988cSAaron Tomlin 121beef988cSAaron Tomlin static int __init unloaded_tainted_modules_init(void) 122beef988cSAaron Tomlin { 123beef988cSAaron Tomlin struct dentry *dir; 124beef988cSAaron Tomlin 125beef988cSAaron Tomlin dir = debugfs_create_dir("modules", NULL); 126beef988cSAaron Tomlin debugfs_create_file("unloaded_tainted", 0444, dir, NULL, 127beef988cSAaron Tomlin &unloaded_tainted_modules_fops); 128beef988cSAaron Tomlin 129beef988cSAaron Tomlin return 0; 130beef988cSAaron Tomlin } 131beef988cSAaron Tomlin module_init(unloaded_tainted_modules_init); 132beef988cSAaron Tomlin #endif /* CONFIG_DEBUG_FS */ 133