diff --git a/kernel/module.c b/kernel/module.c index cb40a4e64a0e..91f3ebe230e3 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2158,6 +2158,7 @@ struct load_info { } index; }; +/* Sets info->hdr and info->len. */ static int copy_and_check(struct load_info *info, const void __user *umod, unsigned long len) { int err; @@ -2199,6 +2200,39 @@ free_hdr: return err; } +static int rewrite_section_headers(struct load_info *info) +{ + unsigned int i; + + /* This should always be true, but let's be sure. */ + info->sechdrs[0].sh_addr = 0; + + for (i = 1; i < info->hdr->e_shnum; i++) { + Elf_Shdr *shdr = &info->sechdrs[i]; + if (shdr->sh_type != SHT_NOBITS + && info->len < shdr->sh_offset + shdr->sh_size) { + printk(KERN_ERR "Module len %lu truncated\n", + info->len); + return -ENOEXEC; + } + + /* Mark all sections sh_addr with their address in the + temporary image. */ + shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset; + +#ifndef CONFIG_MODULE_UNLOAD + /* Don't load .exit sections */ + if (strstarts(info->secstrings+shdr->sh_name, ".exit")) + shdr->sh_flags &= ~(unsigned long)SHF_ALLOC; +#endif + /* Don't keep modinfo and version sections. */ + if (!strcmp(info->secstrings+shdr->sh_name, "__versions") + || !strcmp(info->secstrings+shdr->sh_name, ".modinfo")) + shdr->sh_flags &= ~(unsigned long)SHF_ALLOC; + } + return 0; +} + /* * Set up our basic convenience variables (pointers to section headers, * search for module section index etc), and do some basic section @@ -2210,33 +2244,27 @@ free_hdr: static struct module *setup_load_info(struct load_info *info) { 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; - info->sechdrs[0].sh_addr = 0; + info->secstrings = (void *)info->hdr + + info->sechdrs[info->hdr->e_shstrndx].sh_offset; + err = rewrite_section_headers(info); + if (err) + return ERR_PTR(err); + + /* Find internal symbols and strings. */ for (i = 1; i < info->hdr->e_shnum; i++) { - if (info->sechdrs[i].sh_type != SHT_NOBITS - && info->len < info->sechdrs[i].sh_offset + info->sechdrs[i].sh_size) - goto truncated; - - /* Mark all sections sh_addr with their address in the - temporary image. */ - info->sechdrs[i].sh_addr = (size_t)info->hdr + info->sechdrs[i].sh_offset; - - /* Internal symbols and strings. */ if (info->sechdrs[i].sh_type == SHT_SYMTAB) { info->index.sym = i; info->index.str = info->sechdrs[i].sh_link; - info->strtab = (char *)info->hdr + info->sechdrs[info->index.str].sh_offset; + info->strtab = (char *)info->hdr + + info->sechdrs[info->index.str].sh_offset; + break; } -#ifndef CONFIG_MODULE_UNLOAD - /* Don't load .exit sections */ - if (strstarts(info->secstrings+info->sechdrs[i].sh_name, ".exit")) - info->sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC; -#endif } info->index.mod = find_sec(info->hdr, info->sechdrs, info->secstrings, @@ -2258,19 +2286,11 @@ static struct module *setup_load_info(struct load_info *info) info->index.info = find_sec(info->hdr, info->sechdrs, info->secstrings, ".modinfo"); info->index.pcpu = find_pcpusec(info->hdr, info->sechdrs, info->secstrings); - /* Don't keep modinfo and version sections. */ - info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC; - info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC; - /* Check module struct version now, before we try to use module. */ if (!check_modstruct_version(info->sechdrs, info->index.vers, mod)) return ERR_PTR(-ENOEXEC); return mod; - - truncated: - printk(KERN_ERR "Module len %lu truncated\n", info->len); - return ERR_PTR(-ENOEXEC); } static int check_modinfo(struct module *mod,