diff options
| -rw-r--r-- | kernel/module.c | 122 |
1 files changed, 75 insertions, 47 deletions
diff --git a/kernel/module.c b/kernel/module.c index 19ddcb0dba3..d8faf35cba8 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1803,7 +1803,7 @@ static char *next_string(char *string, unsigned long *secsize) return string; } -static char *get_modinfo(Elf_Shdr *sechdrs, +static char *get_modinfo(const Elf_Shdr *sechdrs, unsigned int info, const char *tag) { @@ -2109,6 +2109,73 @@ static inline void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr, } #endif +static int copy_and_check(Elf_Ehdr **hdrp, + const void __user *umod, unsigned long len) +{ + int err; + Elf_Ehdr *hdr; + + if (len < sizeof(*hdr)) + return -ENOEXEC; + + /* Suck in entire file: we'll want most of it. */ + /* vmalloc barfs on "unusual" numbers. Check here */ + if (len > 64 * 1024 * 1024 || (hdr = *hdrp = vmalloc(len)) == NULL) + return -ENOMEM; + + if (copy_from_user(hdr, umod, len) != 0) { + err = -EFAULT; + goto free_hdr; + } + + /* Sanity checks against insmoding binaries or wrong arch, + weird elf version */ + if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0 + || hdr->e_type != ET_REL + || !elf_check_arch(hdr) + || hdr->e_shentsize != sizeof(Elf_Shdr)) { + err = -ENOEXEC; + goto free_hdr; + } + + if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) { + err = -ENOEXEC; + goto free_hdr; + } + return 0; + +free_hdr: + vfree(hdr); + return err; +} + +static int check_modinfo(struct module *mod, + const Elf_Shdr *sechdrs, + unsigned int infoindex, unsigned int versindex) +{ + const char *modmagic = get_modinfo(sechdrs, infoindex, "vermagic"); + int err; + + /* This is allowed: modprobe --force will invalidate it. */ + if (!modmagic) { + err = try_to_force_load(mod, "bad vermagic"); + if (err) + return err; + } else if (!same_magic(modmagic, vermagic, versindex)) { + printk(KERN_ERR "%s: version magic '%s' should be '%s'\n", + mod->name, modmagic, vermagic); + return -ENOEXEC; + } + + if (get_modinfo(sechdrs, infoindex, "staging")) { + add_taint_module(mod, TAINT_CRAP); + printk(KERN_WARNING "%s: module is from the staging directory," + " the quality is unknown, you have been warned.\n", + mod->name); + } + return 0; +} + static void find_module_sections(struct module *mod, Elf_Ehdr *hdr, Elf_Shdr *sechdrs, const char *secstrings) { @@ -2246,14 +2313,13 @@ static noinline struct module *load_module(void __user *umod, { Elf_Ehdr *hdr; Elf_Shdr *sechdrs; - char *secstrings, *args, *modmagic, *strtab = NULL; - char *staging; + char *secstrings, *args, *strtab = NULL; unsigned int i; unsigned int symindex = 0; unsigned int strindex = 0; unsigned int modindex, versindex, infoindex, pcpuindex; struct module *mod; - long err = 0; + long err; unsigned long symoffs, stroffs, *strmap; void __percpu *percpu; struct _ddebug *debug = NULL; @@ -2263,31 +2329,10 @@ static noinline struct module *load_module(void __user *umod, DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n", umod, len, uargs); - if (len < sizeof(*hdr)) - return ERR_PTR(-ENOEXEC); - - /* Suck in entire file: we'll want most of it. */ - /* vmalloc barfs on "unusual" numbers. Check here */ - if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL) - return ERR_PTR(-ENOMEM); - - if (copy_from_user(hdr, umod, len) != 0) { - err = -EFAULT; - goto free_hdr; - } - - /* Sanity checks against insmoding binaries or wrong arch, - weird elf version */ - if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0 - || hdr->e_type != ET_REL - || !elf_check_arch(hdr) - || hdr->e_shentsize != sizeof(*sechdrs)) { - err = -ENOEXEC; - goto free_hdr; - } - if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) - goto truncated; + err = copy_and_check(&hdr, umod, len); + if (err) + return ERR_PTR(err); /* Convenience variables */ sechdrs = (void *)hdr + hdr->e_shoff; @@ -2347,26 +2392,9 @@ static noinline struct module *load_module(void __user *umod, goto free_hdr; } - modmagic = get_modinfo(sechdrs, infoindex, "vermagic"); - /* This is allowed: modprobe --force will invalidate it. */ - if (!modmagic) { - err = try_to_force_load(mod, "bad vermagic"); - if (err) - goto free_hdr; - } else if (!same_magic(modmagic, vermagic, versindex)) { - printk(KERN_ERR "%s: version magic '%s' should be '%s'\n", - mod->name, modmagic, vermagic); - err = -ENOEXEC; + err = check_modinfo(mod, sechdrs, infoindex, versindex); + if (err) goto free_hdr; - } - - staging = get_modinfo(sechdrs, infoindex, "staging"); - if (staging) { - add_taint_module(mod, TAINT_CRAP); - printk(KERN_WARNING "%s: module is from the staging directory," - " the quality is unknown, you have been warned.\n", - mod->name); - } /* Now copy in args */ args = strndup_user(uargs, ~0UL >> 1); |