diff --git a/arch/arm/include/asm/module.h b/arch/arm/include/asm/module.h index 89ad0596033a..9e81b7c498d8 100644 --- a/arch/arm/include/asm/module.h +++ b/arch/arm/include/asm/module.h @@ -34,6 +34,7 @@ struct mod_arch_specific { #endif }; +struct module; u32 get_module_plt(struct module *mod, unsigned long loc, Elf32_Addr val); /* diff --git a/include/linux/module.h b/include/linux/module.h index d44df9b2c131..f807f15bebbe 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -266,7 +266,7 @@ extern int modules_disabled; /* for sysctl */ /* Get/put a kernel symbol (calls must be symmetric) */ void *__symbol_get(const char *symbol); void *__symbol_get_gpl(const char *symbol); -#define symbol_get(x) ((typeof(&x))(__symbol_get(VMLINUX_SYMBOL_STR(x)))) +#define symbol_get(x) ((typeof(&x))(__symbol_get(__stringify(x)))) /* modules using other modules: kdb wants to see this. */ struct module_use { @@ -575,7 +575,7 @@ extern void __noreturn __module_put_and_exit(struct module *mod, #ifdef CONFIG_MODULE_UNLOAD int module_refcount(struct module *mod); void __symbol_put(const char *symbol); -#define symbol_put(x) __symbol_put(VMLINUX_SYMBOL_STR(x)) +#define symbol_put(x) __symbol_put(__stringify(x)) void symbol_put_addr(void *addr); /* Sometimes we know we already have a refcount, and it's easier not diff --git a/kernel/module-internal.h b/kernel/module-internal.h index 915e123a430f..79c9be2dbbe9 100644 --- a/kernel/module-internal.h +++ b/kernel/module-internal.h @@ -9,4 +9,27 @@ * 2 of the Licence, or (at your option) any later version. */ -extern int mod_verify_sig(const void *mod, unsigned long *_modlen); +#include +#include + +struct load_info { + const char *name; + /* pointer to module in temporary copy, freed at end of load_module() */ + struct module *mod; + Elf_Ehdr *hdr; + unsigned long len; + Elf_Shdr *sechdrs; + char *secstrings, *strtab; + unsigned long symoffs, stroffs; + struct _ddebug *debug; + unsigned int num_debug; + bool sig_ok; +#ifdef CONFIG_KALLSYMS + unsigned long mod_kallsyms_init_off; +#endif + struct { + unsigned int sym, str, mod, vers, info, pcpu; + } index; +}; + +extern int mod_verify_sig(const void *mod, struct load_info *info); diff --git a/kernel/module.c b/kernel/module.c index a7615d661910..b046a32520d8 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -307,24 +307,6 @@ int unregister_module_notifier(struct notifier_block *nb) } EXPORT_SYMBOL(unregister_module_notifier); -struct load_info { - const char *name; - Elf_Ehdr *hdr; - unsigned long len; - Elf_Shdr *sechdrs; - char *secstrings, *strtab; - unsigned long symoffs, stroffs; - struct _ddebug *debug; - unsigned int num_debug; - bool sig_ok; -#ifdef CONFIG_KALLSYMS - unsigned long mod_kallsyms_init_off; -#endif - struct { - unsigned int sym, str, mod, vers, info, pcpu; - } index; -}; - /* * We require a truly strong try_module_get(): 0 means success. * Otherwise an error is returned due to ongoing or failed @@ -1339,14 +1321,12 @@ static inline int check_modstruct_version(const struct load_info *info, * locking is necessary -- use preempt_disable() to placate lockdep. */ preempt_disable(); - if (!find_symbol(VMLINUX_SYMBOL_STR(module_layout), NULL, - &crc, true, false)) { + if (!find_symbol("module_layout", NULL, &crc, true, false)) { preempt_enable(); BUG(); } preempt_enable(); - return check_version(info, VMLINUX_SYMBOL_STR(module_layout), - mod, crc); + return check_version(info, "module_layout", mod, crc); } /* First part is kernel version, which we ignore if module has crcs. */ @@ -2059,21 +2039,19 @@ static int copy_module_elf(struct module *mod, struct load_info *info) /* Elf section header table */ size = sizeof(*info->sechdrs) * info->hdr->e_shnum; - mod->klp_info->sechdrs = kmalloc(size, GFP_KERNEL); + mod->klp_info->sechdrs = kmemdup(info->sechdrs, size, GFP_KERNEL); if (mod->klp_info->sechdrs == NULL) { ret = -ENOMEM; goto free_info; } - memcpy(mod->klp_info->sechdrs, info->sechdrs, size); /* Elf section name string table */ size = info->sechdrs[info->hdr->e_shstrndx].sh_size; - mod->klp_info->secstrings = kmalloc(size, GFP_KERNEL); + mod->klp_info->secstrings = kmemdup(info->secstrings, size, GFP_KERNEL); if (mod->klp_info->secstrings == NULL) { ret = -ENOMEM; goto free_sechdrs; } - memcpy(mod->klp_info->secstrings, info->secstrings, size); /* Elf symbol section index */ symndx = info->index.sym; @@ -2282,9 +2260,9 @@ static int simplify_symbols(struct module *mod, const struct load_info *info) if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK) break; - pr_warn("%s: Unknown symbol %s (err %li)\n", - mod->name, name, PTR_ERR(ksym)); ret = PTR_ERR(ksym) ?: -ENOENT; + pr_warn("%s: Unknown symbol %s (err %d)\n", + mod->name, name, ret); break; default: @@ -2486,7 +2464,11 @@ static char *get_modinfo(struct load_info *info, const char *tag) Elf_Shdr *infosec = &info->sechdrs[info->index.info]; unsigned long size = infosec->sh_size; - for (p = (char *)infosec->sh_addr; p; p = next_string(p, &size)) { + /* + * get_modinfo() calls made before rewrite_section_headers() + * must use sh_offset, as sh_addr isn't set! + */ + for (p = (char *)info->hdr + infosec->sh_offset; p; p = next_string(p, &size)) { if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') return p + taglen + 1; } @@ -2774,7 +2756,7 @@ static int module_sig_check(struct load_info *info, int flags) memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) { /* We truncate the module to discard the signature */ info->len -= markerlen; - err = mod_verify_sig(mod, &info->len); + err = mod_verify_sig(mod, info); } if (!err) { @@ -2926,17 +2908,7 @@ static int rewrite_section_headers(struct load_info *info, int flags) } /* Track but don't keep modinfo and version sections. */ - if (flags & MODULE_INIT_IGNORE_MODVERSIONS) - info->index.vers = 0; /* Pretend no __versions section! */ - else - info->index.vers = find_sec(info, "__versions"); info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC; - - info->index.info = find_sec(info, ".modinfo"); - if (!info->index.info) - info->name = "(missing .modinfo section)"; - else - info->name = get_modinfo(info, "name"); info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC; return 0; @@ -2947,23 +2919,24 @@ static int rewrite_section_headers(struct load_info *info, int flags) * search for module section index etc), and do some basic section * verification. * - * Return the temporary module pointer (we'll replace it with the final - * one when we move the module sections around). + * Set info->mod to the temporary copy of the module in info->hdr. The final one + * will be allocated in move_module(). */ -static struct module *setup_load_info(struct load_info *info, int flags) +static int setup_load_info(struct load_info *info, int flags) { unsigned int i; - int err; - struct module *mod; /* Set up the convenience variables */ info->sechdrs = (void *)info->hdr + info->hdr->e_shoff; info->secstrings = (void *)info->hdr + info->sechdrs[info->hdr->e_shstrndx].sh_offset; - err = rewrite_section_headers(info, flags); - if (err) - return ERR_PTR(err); + /* Try to find a name early so we can log errors with a module name */ + info->index.info = find_sec(info, ".modinfo"); + if (!info->index.info) + info->name = "(missing .modinfo section)"; + else + info->name = get_modinfo(info, "name"); /* Find internal symbols and strings. */ for (i = 1; i < info->hdr->e_shnum; i++) { @@ -2976,34 +2949,35 @@ static struct module *setup_load_info(struct load_info *info, int flags) } } + if (info->index.sym == 0) { + pr_warn("%s: module has no symbols (stripped?)\n", info->name); + return -ENOEXEC; + } + info->index.mod = find_sec(info, ".gnu.linkonce.this_module"); if (!info->index.mod) { pr_warn("%s: No module found in object\n", info->name ?: "(missing .modinfo name field)"); - return ERR_PTR(-ENOEXEC); + return -ENOEXEC; } /* This is temporary: point mod into copy of data. */ - mod = (void *)info->sechdrs[info->index.mod].sh_addr; + info->mod = (void *)info->hdr + info->sechdrs[info->index.mod].sh_offset; /* - * If we didn't load the .modinfo 'name' field, fall back to + * If we didn't load the .modinfo 'name' field earlier, fall back to * on-disk struct mod 'name' field. */ if (!info->name) - info->name = mod->name; + info->name = info->mod->name; - if (info->index.sym == 0) { - pr_warn("%s: module has no symbols (stripped?)\n", info->name); - return ERR_PTR(-ENOEXEC); - } + if (flags & MODULE_INIT_IGNORE_MODVERSIONS) + info->index.vers = 0; /* Pretend no __versions section! */ + else + info->index.vers = find_sec(info, "__versions"); info->index.pcpu = find_pcpusec(info); - /* Check module struct version now, before we try to use module. */ - if (!check_modstruct_version(info, mod)) - return ERR_PTR(-ENOEXEC); - - return mod; + return 0; } static int check_modinfo(struct module *mod, struct load_info *info, int flags) @@ -3298,25 +3272,17 @@ 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(info->name)) - return ERR_PTR(-EPERM); - - err = check_modinfo(mod, info, flags); + err = check_modinfo(info->mod, info, flags); if (err) return ERR_PTR(err); /* Allow arches to frob section contents and sizes. */ err = module_frob_arch_sections(info->hdr, info->sechdrs, - info->secstrings, mod); + info->secstrings, info->mod); if (err < 0) return ERR_PTR(err); @@ -3335,11 +3301,11 @@ static struct module *layout_and_allocate(struct load_info *info, int flags) /* 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. */ - layout_sections(mod, info); - layout_symtab(mod, info); + layout_sections(info->mod, info); + layout_symtab(info->mod, info); /* Allocate and move to the final place */ - err = move_module(mod, info); + err = move_module(info->mod, info); if (err) return ERR_PTR(err); @@ -3657,17 +3623,36 @@ static int load_module(struct load_info *info, const char __user *uargs, int flags) { struct module *mod; - long err; + long err = 0; char *after_dashes; + err = elf_header_check(info); + if (err) + goto free_copy; + + err = setup_load_info(info, flags); + if (err) + goto free_copy; + + if (blacklisted(info->name)) { + err = -EPERM; + goto free_copy; + } + err = module_sig_check(info, flags); if (err) goto free_copy; - err = elf_header_check(info); + err = rewrite_section_headers(info, flags); if (err) goto free_copy; + /* Check module struct version now, before we try to use module. */ + if (!check_modstruct_version(info, info->mod)) { + err = -ENOEXEC; + goto free_copy; + } + /* Figure out module layout, and allocate all the memory. */ mod = layout_and_allocate(info, flags); if (IS_ERR(mod)) { @@ -4067,7 +4052,7 @@ static unsigned long mod_find_symname(struct module *mod, const char *name) for (i = 0; i < kallsyms->num_symtab; i++) if (strcmp(name, symname(kallsyms, i)) == 0 && - kallsyms->symtab[i].st_info != 'U') + kallsyms->symtab[i].st_shndx != SHN_UNDEF) return kallsyms->symtab[i].st_value; return 0; } @@ -4113,6 +4098,10 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, if (mod->state == MODULE_STATE_UNFORMED) continue; for (i = 0; i < kallsyms->num_symtab; i++) { + + if (kallsyms->symtab[i].st_shndx == SHN_UNDEF) + continue; + ret = fn(data, symname(kallsyms, i), mod, kallsyms->symtab[i].st_value); if (ret != 0) diff --git a/kernel/module_signing.c b/kernel/module_signing.c index 937c844bee4a..f2075ce8e4b3 100644 --- a/kernel/module_signing.c +++ b/kernel/module_signing.c @@ -45,10 +45,10 @@ struct module_signature { /* * Verify the signature on a module. */ -int mod_verify_sig(const void *mod, unsigned long *_modlen) +int mod_verify_sig(const void *mod, struct load_info *info) { struct module_signature ms; - size_t modlen = *_modlen, sig_len; + size_t sig_len, modlen = info->len; pr_devel("==>%s(,%zu)\n", __func__, modlen); @@ -62,10 +62,11 @@ int mod_verify_sig(const void *mod, unsigned long *_modlen) if (sig_len >= modlen) return -EBADMSG; modlen -= sig_len; - *_modlen = modlen; + info->len = modlen; if (ms.id_type != PKEY_ID_PKCS7) { - pr_err("Module is not signed with expected PKCS#7 message\n"); + pr_err("%s: Module is not signed with expected PKCS#7 message\n", + info->name); return -ENOPKG; } @@ -76,7 +77,8 @@ int mod_verify_sig(const void *mod, unsigned long *_modlen) ms.__pad[0] != 0 || ms.__pad[1] != 0 || ms.__pad[2] != 0) { - pr_err("PKCS#7 signature info has unexpected non-zero params\n"); + pr_err("%s: PKCS#7 signature info has unexpected non-zero params\n", + info->name); return -EBADMSG; }