diff options
Diffstat (limited to 'kernel/module')
| -rw-r--r-- | kernel/module/Kconfig | 3 | ||||
| -rw-r--r-- | kernel/module/internal.h | 6 | ||||
| -rw-r--r-- | kernel/module/main.c | 29 | ||||
| -rw-r--r-- | kernel/module/strict_rwx.c | 63 |
4 files changed, 68 insertions, 33 deletions
diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig index 0ea1b2970a23..c3ced519e14b 100644 --- a/kernel/module/Kconfig +++ b/kernel/module/Kconfig @@ -362,8 +362,7 @@ config MODPROBE_PATH userspace can still load modules explicitly). config TRIM_UNUSED_KSYMS - bool "Trim unused exported kernel symbols" if EXPERT - depends on !COMPILE_TEST + bool "Trim unused exported kernel symbols" help The kernel and some modules make many symbols available for other modules to use via EXPORT_SYMBOL() and variants. Depending diff --git a/kernel/module/internal.h b/kernel/module/internal.h index c8b7b4dcf782..2ebece8a789f 100644 --- a/kernel/module/internal.h +++ b/kernel/module/internal.h @@ -322,9 +322,9 @@ static inline struct module *mod_find(unsigned long addr, struct mod_tree_root * } #endif /* CONFIG_MODULES_TREE_LOOKUP */ -void module_enable_ro(const struct module *mod, bool after_init); -void module_enable_nx(const struct module *mod); -void module_enable_x(const struct module *mod); +int module_enable_rodata_ro(const struct module *mod, bool after_init); +int module_enable_data_nx(const struct module *mod); +int module_enable_text_rox(const struct module *mod); int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, char *secstrings, struct module *mod); diff --git a/kernel/module/main.c b/kernel/module/main.c index 36681911c05a..e1e8a7a9d6c1 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -2489,6 +2489,11 @@ static void do_free_init(struct work_struct *w) } } +void flush_module_init_free_work(void) +{ + flush_work(&init_free_wq); +} + #undef MODULE_PARAM_PREFIX #define MODULE_PARAM_PREFIX "module." /* Default value for module->async_probe_requested */ @@ -2571,7 +2576,9 @@ 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); + ret = module_enable_rodata_ro(mod, true); + if (ret) + goto fail_mutex_unlock; mod_tree_remove_init(mod); module_arch_freeing_init(mod); for_class_mod_mem_type(type, init) { @@ -2593,8 +2600,8 @@ static noinline int do_init_module(struct module *mod) * Note that module_alloc() on most architectures creates W+X page * mappings which won't be cleaned up until do_free_init() runs. Any * code such as mark_rodata_ro() which depends on those mappings to - * be cleaned up needs to sync with the queued work - ie - * rcu_barrier() + * be cleaned up needs to sync with the queued work by invoking + * flush_module_init_free_work(). */ if (llist_add(&freeinit->node, &init_free_list)) schedule_work(&init_free_wq); @@ -2609,6 +2616,8 @@ static noinline int do_init_module(struct module *mod) return 0; +fail_mutex_unlock: + mutex_unlock(&module_mutex); fail_free_freeinit: kfree(freeinit); fail: @@ -2736,9 +2745,15 @@ static int complete_formation(struct module *mod, struct load_info *info) module_bug_finalize(info->hdr, info->sechdrs, mod); module_cfi_finalize(info->hdr, info->sechdrs, mod); - module_enable_ro(mod, false); - module_enable_nx(mod); - module_enable_x(mod); + err = module_enable_rodata_ro(mod, false); + if (err) + goto out_strict_rwx; + err = module_enable_data_nx(mod); + if (err) + goto out_strict_rwx; + err = module_enable_text_rox(mod); + if (err) + goto out_strict_rwx; /* * Mark state as coming so strong_try_module_get() ignores us, @@ -2749,6 +2764,8 @@ static int complete_formation(struct module *mod, struct load_info *info) return 0; +out_strict_rwx: + module_bug_cleanup(mod); out: mutex_unlock(&module_mutex); return err; diff --git a/kernel/module/strict_rwx.c b/kernel/module/strict_rwx.c index a2b656b4e3d2..c45caa4690e5 100644 --- a/kernel/module/strict_rwx.c +++ b/kernel/module/strict_rwx.c @@ -11,13 +11,16 @@ #include <linux/set_memory.h> #include "internal.h" -static void module_set_memory(const struct module *mod, enum mod_mem_type type, - int (*set_memory)(unsigned long start, int num_pages)) +static int module_set_memory(const struct module *mod, enum mod_mem_type type, + int (*set_memory)(unsigned long start, int num_pages)) { const struct module_memory *mod_mem = &mod->mem[type]; + if (!mod_mem->base) + return 0; + set_vm_flush_reset_perms(mod_mem->base); - set_memory((unsigned long)mod_mem->base, mod_mem->size >> PAGE_SHIFT); + return set_memory((unsigned long)mod_mem->base, mod_mem->size >> PAGE_SHIFT); } /* @@ -26,37 +29,53 @@ static void module_set_memory(const struct module *mod, enum mod_mem_type type, * CONFIG_STRICT_MODULE_RWX because they are needed regardless of whether we * are strict. */ -void module_enable_x(const struct module *mod) +int module_enable_text_rox(const struct module *mod) { - for_class_mod_mem_type(type, text) - module_set_memory(mod, type, set_memory_x); + for_class_mod_mem_type(type, text) { + int ret; + + if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX)) + ret = module_set_memory(mod, type, set_memory_rox); + else + ret = module_set_memory(mod, type, set_memory_x); + if (ret) + return ret; + } + return 0; } -void module_enable_ro(const struct module *mod, bool after_init) +int module_enable_rodata_ro(const struct module *mod, bool after_init) { - if (!IS_ENABLED(CONFIG_STRICT_MODULE_RWX)) - return; -#ifdef CONFIG_STRICT_MODULE_RWX - if (!rodata_enabled) - return; -#endif + int ret; + + if (!IS_ENABLED(CONFIG_STRICT_MODULE_RWX) || !rodata_enabled) + return 0; - module_set_memory(mod, MOD_TEXT, set_memory_ro); - module_set_memory(mod, MOD_INIT_TEXT, set_memory_ro); - module_set_memory(mod, MOD_RODATA, set_memory_ro); - module_set_memory(mod, MOD_INIT_RODATA, set_memory_ro); + ret = module_set_memory(mod, MOD_RODATA, set_memory_ro); + if (ret) + return ret; + ret = module_set_memory(mod, MOD_INIT_RODATA, set_memory_ro); + if (ret) + return ret; if (after_init) - module_set_memory(mod, MOD_RO_AFTER_INIT, set_memory_ro); + return module_set_memory(mod, MOD_RO_AFTER_INIT, set_memory_ro); + + return 0; } -void module_enable_nx(const struct module *mod) +int module_enable_data_nx(const struct module *mod) { if (!IS_ENABLED(CONFIG_STRICT_MODULE_RWX)) - return; + return 0; - for_class_mod_mem_type(type, data) - module_set_memory(mod, type, set_memory_nx); + for_class_mod_mem_type(type, data) { + int ret = module_set_memory(mod, type, set_memory_nx); + + if (ret) + return ret; + } + return 0; } int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, |