diff options
Diffstat (limited to 'kernel/module.c')
| -rw-r--r-- | kernel/module.c | 121 |
1 files changed, 100 insertions, 21 deletions
diff --git a/kernel/module.c b/kernel/module.c index a0f48b8b00da..529efae9f481 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -265,7 +265,7 @@ static void module_assert_mutex_or_preempt(void) if (unlikely(!debug_locks)) return; - WARN_ON(!rcu_read_lock_sched_held() && + WARN_ON_ONCE(!rcu_read_lock_sched_held() && !lockdep_is_held(&module_mutex)); #endif } @@ -337,7 +337,7 @@ static inline void add_taint_module(struct module *mod, unsigned flag, * A thread that wants to hold a reference to a module only while it * is running can call this to safely exit. nfsd and lockd use this. */ -void __module_put_and_exit(struct module *mod, long code) +void __noreturn __module_put_and_exit(struct module *mod, long code) { module_put(mod); do_exit(code); @@ -1694,8 +1694,7 @@ static int module_add_modinfo_attrs(struct module *mod) temp_attr = mod->modinfo_attrs; for (i = 0; (attr = modinfo_attrs[i]) && !error; i++) { - if (!attr->test || - (attr->test && attr->test(mod))) { + if (!attr->test || attr->test(mod)) { memcpy(temp_attr, attr, sizeof(*temp_attr)); sysfs_attr_init(&temp_attr->attr); error = sysfs_create_file(&mod->mkobj.kobj, @@ -1859,10 +1858,11 @@ static void mod_sysfs_teardown(struct module *mod) * from modification and any data from execution. * * General layout of module is: - * [text] [read-only-data] [writable data] - * text_size -----^ ^ ^ - * ro_size ------------------------| | - * size -------------------------------------------| + * [text] [read-only-data] [ro-after-init] [writable data] + * text_size -----^ ^ ^ ^ + * ro_size ------------------------| | | + * ro_after_init_size -----------------------------| | + * size -----------------------------------------------------------| * * These values are always page-aligned (as is base) */ @@ -1885,14 +1885,24 @@ static void frob_rodata(const struct module_layout *layout, (layout->ro_size - layout->text_size) >> PAGE_SHIFT); } +static void frob_ro_after_init(const struct module_layout *layout, + int (*set_memory)(unsigned long start, int num_pages)) +{ + BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); + BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1)); + BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1)); + set_memory((unsigned long)layout->base + layout->ro_size, + (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT); +} + static void frob_writable_data(const struct module_layout *layout, int (*set_memory)(unsigned long start, int num_pages)) { BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1)); - BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1)); + BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1)); BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1)); - set_memory((unsigned long)layout->base + layout->ro_size, - (layout->size - layout->ro_size) >> PAGE_SHIFT); + set_memory((unsigned long)layout->base + layout->ro_after_init_size, + (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT); } /* livepatching wants to disable read-only so it can frob module. */ @@ -1900,21 +1910,26 @@ void module_disable_ro(const struct module *mod) { frob_text(&mod->core_layout, set_memory_rw); frob_rodata(&mod->core_layout, set_memory_rw); + frob_ro_after_init(&mod->core_layout, set_memory_rw); frob_text(&mod->init_layout, set_memory_rw); frob_rodata(&mod->init_layout, set_memory_rw); } -void module_enable_ro(const struct module *mod) +void module_enable_ro(const struct module *mod, bool after_init) { frob_text(&mod->core_layout, set_memory_ro); frob_rodata(&mod->core_layout, set_memory_ro); frob_text(&mod->init_layout, set_memory_ro); frob_rodata(&mod->init_layout, set_memory_ro); + + if (after_init) + frob_ro_after_init(&mod->core_layout, set_memory_ro); } static void module_enable_nx(const struct module *mod) { frob_rodata(&mod->core_layout, set_memory_nx); + frob_ro_after_init(&mod->core_layout, set_memory_nx); frob_writable_data(&mod->core_layout, set_memory_nx); frob_rodata(&mod->init_layout, set_memory_nx); frob_writable_data(&mod->init_layout, set_memory_nx); @@ -1923,6 +1938,7 @@ static void module_enable_nx(const struct module *mod) static void module_disable_nx(const struct module *mod) { frob_rodata(&mod->core_layout, set_memory_x); + frob_ro_after_init(&mod->core_layout, set_memory_x); frob_writable_data(&mod->core_layout, set_memory_x); frob_rodata(&mod->init_layout, set_memory_x); frob_writable_data(&mod->init_layout, set_memory_x); @@ -1965,6 +1981,8 @@ static void disable_ro_nx(const struct module_layout *layout) frob_text(layout, set_memory_rw); frob_rodata(layout, set_memory_rw); frob_rodata(layout, set_memory_x); + frob_ro_after_init(layout, set_memory_rw); + frob_ro_after_init(layout, set_memory_x); frob_writable_data(layout, set_memory_x); } @@ -2307,6 +2325,7 @@ static void layout_sections(struct module *mod, struct load_info *info) * finder in the two loops below */ { SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL }, { SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL }, + { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL }, { SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL }, { ARCH_SHF_SMALL | SHF_ALLOC, 0 } }; @@ -2338,7 +2357,11 @@ static void layout_sections(struct module *mod, struct load_info *info) mod->core_layout.size = debug_align(mod->core_layout.size); mod->core_layout.ro_size = mod->core_layout.size; break; - case 3: /* whole core */ + case 2: /* RO after init */ + mod->core_layout.size = debug_align(mod->core_layout.size); + mod->core_layout.ro_after_init_size = mod->core_layout.size; + break; + case 4: /* whole core */ mod->core_layout.size = debug_align(mod->core_layout.size); break; } @@ -2368,7 +2391,14 @@ static void layout_sections(struct module *mod, struct load_info *info) mod->init_layout.size = debug_align(mod->init_layout.size); mod->init_layout.ro_size = mod->init_layout.size; break; - case 3: /* whole init */ + case 2: + /* + * RO after init doesn't apply to init_layout (only + * core_layout), so it just takes the value of ro_size. + */ + mod->init_layout.ro_after_init_size = mod->init_layout.ro_size; + break; + case 4: /* whole init */ mod->init_layout.size = debug_align(mod->init_layout.size); break; } @@ -2688,13 +2718,18 @@ static inline void kmemleak_load_module(const struct module *mod, #endif #ifdef CONFIG_MODULE_SIG -static int module_sig_check(struct load_info *info) +static int module_sig_check(struct load_info *info, int flags) { int err = -ENOKEY; const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1; const void *mod = info->hdr; - if (info->len > markerlen && + /* + * Require flags == 0, as a module with version information + * removed is no longer the module that was signed + */ + if (flags == 0 && + info->len > markerlen && memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) { /* We truncate the module to discard the signature */ info->len -= markerlen; @@ -2713,7 +2748,7 @@ static int module_sig_check(struct load_info *info) return err; } #else /* !CONFIG_MODULE_SIG */ -static int module_sig_check(struct load_info *info) +static int module_sig_check(struct load_info *info, int flags) { return 0; } @@ -2921,8 +2956,12 @@ static int check_modinfo(struct module *mod, struct load_info *info, int flags) return -ENOEXEC; } - if (!get_modinfo(info, "intree")) + if (!get_modinfo(info, "intree")) { + if (!test_taint(TAINT_OOT_MODULE)) + pr_warn("%s: loading out-of-tree module taints kernel.\n", + mod->name); add_taint_module(mod, TAINT_OOT_MODULE, LOCKDEP_STILL_OK); + } if (get_modinfo(info, "staging")) { add_taint_module(mod, TAINT_CRAP, LOCKDEP_STILL_OK); @@ -3091,6 +3130,8 @@ static int move_module(struct module *mod, struct load_info *info) static int check_module_license_and_versions(struct module *mod) { + int prev_taint = test_taint(TAINT_PROPRIETARY_MODULE); + /* * ndiswrapper is under GPL by itself, but loads proprietary modules. * Don't use add_taint_module(), as it would prevent ndiswrapper from @@ -3109,6 +3150,9 @@ static int check_module_license_and_versions(struct module *mod) add_taint_module(mod, TAINT_PROPRIETARY_MODULE, LOCKDEP_NOW_UNRELIABLE); + if (!prev_taint && test_taint(TAINT_PROPRIETARY_MODULE)) + pr_warn("%s: module license taints kernel.\n", mod->name); + #ifdef CONFIG_MODVERSIONS if ((mod->num_syms && !mod->crcs) || (mod->num_gpl_syms && !mod->gpl_crcs) @@ -3156,16 +3200,41 @@ int __weak module_frob_arch_sections(Elf_Ehdr *hdr, return 0; } +/* module_blacklist is a comma-separated list of module names */ +static char *module_blacklist; +static bool blacklisted(char *module_name) +{ + const char *p; + size_t len; + + if (!module_blacklist) + return false; + + for (p = module_blacklist; *p; p += len) { + len = strcspn(p, ","); + if (strlen(module_name) == len && !memcmp(module_name, p, len)) + return true; + if (p[len] == ',') + len++; + } + return false; +} +core_param(module_blacklist, module_blacklist, charp, 0400); + static struct module *layout_and_allocate(struct load_info *info, int flags) { /* Module within temporary copy. */ struct module *mod; + unsigned int ndx; int err; mod = setup_load_info(info, flags); if (IS_ERR(mod)) return mod; + if (blacklisted(mod->name)) + return ERR_PTR(-EPERM); + err = check_modinfo(mod, info, flags); if (err) return ERR_PTR(err); @@ -3179,6 +3248,15 @@ static struct module *layout_and_allocate(struct load_info *info, int flags) /* We will do a special allocation for per-cpu sections later. */ info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC; + /* + * Mark ro_after_init section with SHF_RO_AFTER_INIT so that + * layout_sections() can put it in the right place. + * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set. + */ + ndx = find_sec(info, ".data..ro_after_init"); + if (ndx) + info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT; + /* Determine total sizes, and put offsets in sh_entsize. For now this is done generically; there doesn't appear to be any special cases for the architectures. */ @@ -3345,12 +3423,14 @@ static noinline int do_init_module(struct module *mod) /* Switch to core kallsyms now init is done: kallsyms may be walking! */ rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms); #endif + module_enable_ro(mod, true); mod_tree_remove_init(mod); disable_ro_nx(&mod->init_layout); module_arch_freeing_init(mod); mod->init_layout.base = NULL; mod->init_layout.size = 0; mod->init_layout.ro_size = 0; + mod->init_layout.ro_after_init_size = 0; mod->init_layout.text_size = 0; /* * We want to free module_init, but be aware that kallsyms may be @@ -3442,8 +3522,7 @@ static int complete_formation(struct module *mod, struct load_info *info) /* This relies on module_mutex for list integrity. */ module_bug_finalize(info->hdr, info->sechdrs, mod); - /* Set RO and NX regions */ - module_enable_ro(mod); + module_enable_ro(mod, false); module_enable_nx(mod); /* Mark state as coming so strong_try_module_get() ignores us, @@ -3499,7 +3578,7 @@ static int load_module(struct load_info *info, const char __user *uargs, long err; char *after_dashes; - err = module_sig_check(info); + err = module_sig_check(info, flags); if (err) goto free_copy; |