5 files changed, 223 insertions, 148 deletions

diff --git a/arch/x86/syscalls/syscall_32.tbl b/arch/x86/syscalls/syscall_32.tbl
index a47103fbc692..83b3838417ed 100644
--- a/arch/x86/syscalls/syscall_32.tbl
+++ b/arch/x86/syscalls/syscall_32.tbl
@@ -356,3 +356,4 @@
 347     i386    process_vm_readv        sys_process_vm_readv            compat_sys_process_vm_readv
 348     i386    process_vm_writev       sys_process_vm_writev           compat_sys_process_vm_writev
 349     i386    kcmp                    sys_kcmp
+350     i386    finit_module            sys_finit_module
diff --git a/arch/x86/syscalls/syscall_64.tbl b/arch/x86/syscalls/syscall_64.tbl
index a582bfed95bb..7c58c84b7bc8 100644
--- a/arch/x86/syscalls/syscall_64.tbl
+++ b/arch/x86/syscalls/syscall_64.tbl
@@ -319,6 +319,7 @@
 310     64      process_vm_readv        sys_process_vm_readv
 311     64      process_vm_writev       sys_process_vm_writev
 312     common  kcmp                    sys_kcmp
+313     common  finit_module            sys_finit_module
 
 #
 # x32-specific system call numbers start at 512 to avoid cache impact
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 727f0cd73921..32bc035bcd68 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -868,4 +868,5 @@ asmlinkage long sys_process_vm_writev(pid_t pid,
 
 asmlinkage long sys_kcmp(pid_t pid1, pid_t pid2, int type,
                          unsigned long idx1, unsigned long idx2);
+asmlinkage long sys_finit_module(int fd, const char __user *uargs);
 #endif
diff --git a/kernel/module.c b/kernel/module.c
index 6e48c3a43599..6d2c4e4ca1f5 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -21,6 +21,7 @@
 #include <linux/ftrace_event.h>
 #include <linux/init.h>
 #include <linux/kallsyms.h>
+#include <linux/file.h>
 #include <linux/fs.h>
 #include <linux/sysfs.h>
 #include <linux/kernel.h>
@@ -2425,18 +2426,17 @@ static inline void kmemleak_load_module(const struct module *mod,
 #endif
 
 #ifdef CONFIG_MODULE_SIG
-static int module_sig_check(struct load_info *info,
-                            const void *mod, unsigned long *_len)
+static int module_sig_check(struct load_info *info)
 {
         int err = -ENOKEY;
-        unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
-        unsigned long len = *_len;
+        const unsigned long markerlen = sizeof(MODULE_SIG_STRING) - 1;
+        const void *mod = info->hdr;
 
-        if (len > markerlen &&
-            memcmp(mod + len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
+        if (info->len > markerlen &&
+            memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
                 /* We truncate the module to discard the signature */
-                *_len -= markerlen;
-                err = mod_verify_sig(mod, _len);
+                info->len -= markerlen;
+                err = mod_verify_sig(mod, &info->len);
         }
 
         if (!err) {
@@ -2454,59 +2454,97 @@ static int module_sig_check(struct load_info *info,
         return err;
 }
 #else /* !CONFIG_MODULE_SIG */
-static int module_sig_check(struct load_info *info,
-                            void *mod, unsigned long *len)
+static int module_sig_check(struct load_info *info)
 {
         return 0;
 }
 #endif /* !CONFIG_MODULE_SIG */
 
-/* Sets info->hdr, info->len and info->sig_ok. */
-static int copy_and_check(struct load_info *info,
-                          const void __user *umod, unsigned long len,
-                          const char __user *uargs)
+/* Sanity checks against invalid binaries, wrong arch, weird elf version. */
+static int elf_header_check(struct load_info *info)
 {
-        int err;
-        Elf_Ehdr *hdr;
+        if (info->len < sizeof(*(info->hdr)))
+                return -ENOEXEC;
+
+        if (memcmp(info->hdr->e_ident, ELFMAG, SELFMAG) != 0
+            || info->hdr->e_type != ET_REL
+            || !elf_check_arch(info->hdr)
+            || info->hdr->e_shentsize != sizeof(Elf_Shdr))
+                return -ENOEXEC;
+
+        if (info->hdr->e_shoff >= info->len
+            || (info->hdr->e_shnum * sizeof(Elf_Shdr) >
+                info->len - info->hdr->e_shoff))
+                return -ENOEXEC;
 
-        if (len < sizeof(*hdr))
+        return 0;
+}
+
+/* Sets info->hdr and info->len. */
+static int copy_module_from_user(const void __user *umod, unsigned long len,
+                                  struct load_info *info)
+{
+        info->len = len;
+        if (info->len < sizeof(*(info->hdr)))
                 return -ENOEXEC;
 
         /* Suck in entire file: we'll want most of it. */
-        if ((hdr = vmalloc(len)) == NULL)
+        info->hdr = vmalloc(info->len);
+        if (!info->hdr)
                 return -ENOMEM;
 
-        if (copy_from_user(hdr, umod, len) != 0) {
-                err = -EFAULT;
-                goto free_hdr;
+        if (copy_from_user(info->hdr, umod, info->len) != 0) {
+                vfree(info->hdr);
+                return -EFAULT;
         }
 
-        err = module_sig_check(info, hdr, &len);
+        return 0;
+}
+
+/* Sets info->hdr and info->len. */
+static int copy_module_from_fd(int fd, struct load_info *info)
+{
+        struct file *file;
+        int err;
+        struct kstat stat;
+        loff_t pos;
+        ssize_t bytes = 0;
+
+        file = fget(fd);
+        if (!file)
+                return -ENOEXEC;
+
+        err = vfs_getattr(file->f_vfsmnt, file->f_dentry, &stat);
         if (err)
-                goto free_hdr;
+                goto out;
 
-        /* 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 (stat.size > INT_MAX) {
+                err = -EFBIG;
+                goto out;
         }
-
-        if (hdr->e_shoff >= len ||
-            hdr->e_shnum * sizeof(Elf_Shdr) > len - hdr->e_shoff) {
-                err = -ENOEXEC;
-                goto free_hdr;
+        info->hdr = vmalloc(stat.size);
+        if (!info->hdr) {
+                err = -ENOMEM;
+                goto out;
         }
 
-        info->hdr = hdr;
-        info->len = len;
-        return 0;
+        pos = 0;
+        while (pos < stat.size) {
+                bytes = kernel_read(file, pos, (char *)(info->hdr) + pos,
+                                    stat.size - pos);
+                if (bytes < 0) {
+                        vfree(info->hdr);
+                        err = bytes;
+                        goto out;
+                }
+                if (bytes == 0)
+                        break;
+                pos += bytes;
+        }
+        info->len = pos;
 
-free_hdr:
-        vfree(hdr);
+out:
+        fput(file);
         return err;
 }
 
@@ -2945,33 +2983,123 @@ static bool finished_loading(const char *name)
         return ret;
 }
 
+/* Call module constructors. */
+static void do_mod_ctors(struct module *mod)
+{
+#ifdef CONFIG_CONSTRUCTORS
+        unsigned long i;
+
+        for (i = 0; i < mod->num_ctors; i++)
+                mod->ctors[i]();
+#endif
+}
+
+/* This is where the real work happens */
+static int do_init_module(struct module *mod)
+{
+        int ret = 0;
+
+        blocking_notifier_call_chain(&module_notify_list,
+                        MODULE_STATE_COMING, mod);
+
+        /* Set RO and NX regions for core */
+        set_section_ro_nx(mod->module_core,
+                                mod->core_text_size,
+                                mod->core_ro_size,
+                                mod->core_size);
+
+        /* Set RO and NX regions for init */
+        set_section_ro_nx(mod->module_init,
+                                mod->init_text_size,
+                                mod->init_ro_size,
+                                mod->init_size);
+
+        do_mod_ctors(mod);
+        /* Start the module */
+        if (mod->init != NULL)
+                ret = do_one_initcall(mod->init);
+        if (ret < 0) {
+                /* Init routine failed: abort.  Try to protect us from
+                   buggy refcounters. */
+                mod->state = MODULE_STATE_GOING;
+                synchronize_sched();
+                module_put(mod);
+                blocking_notifier_call_chain(&module_notify_list,
+                                             MODULE_STATE_GOING, mod);
+                free_module(mod);
+                wake_up_all(&module_wq);
+                return ret;
+        }
+        if (ret > 0) {
+                printk(KERN_WARNING
+"%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
+"%s: loading module anyway...\n",
+                       __func__, mod->name, ret,
+                       __func__);
+                dump_stack();
+        }
+
+        /* Now it's a first class citizen! */
+        mod->state = MODULE_STATE_LIVE;
+        blocking_notifier_call_chain(&module_notify_list,
+                                     MODULE_STATE_LIVE, mod);
+
+        /* We need to finish all async code before the module init sequence is done */
+        async_synchronize_full();
+
+        mutex_lock(&module_mutex);
+        /* Drop initial reference. */
+        module_put(mod);
+        trim_init_extable(mod);
+#ifdef CONFIG_KALLSYMS
+        mod->num_symtab = mod->core_num_syms;
+        mod->symtab = mod->core_symtab;
+        mod->strtab = mod->core_strtab;
+#endif
+        unset_module_init_ro_nx(mod);
+        module_free(mod, mod->module_init);
+        mod->module_init = NULL;
+        mod->init_size = 0;
+        mod->init_ro_size = 0;
+        mod->init_text_size = 0;
+        mutex_unlock(&module_mutex);
+        wake_up_all(&module_wq);
+
+        return 0;
+}
+
+static int may_init_module(void)
+{
+        if (!capable(CAP_SYS_MODULE) || modules_disabled)
+                return -EPERM;
+
+        return 0;
+}
+
 /* Allocate and load the module: note that size of section 0 is always
    zero, and we rely on this for optional sections. */
-static struct module *load_module(void __user *umod,
-                                  unsigned long len,
-                                  const char __user *uargs)
+static int load_module(struct load_info *info, const char __user *uargs)
 {
-        struct load_info info = { NULL, };
         struct module *mod, *old;
         long err;
 
-        pr_debug("load_module: umod=%p, len=%lu, uargs=%p\n",
-               umod, len, uargs);
+        err = module_sig_check(info);
+        if (err)
+                goto free_copy;
 
-        /* Copy in the blobs from userspace, check they are vaguely sane. */
-        err = copy_and_check(&info, umod, len, uargs);
+        err = elf_header_check(info);
         if (err)
-                return ERR_PTR(err);
+                goto free_copy;
 
         /* Figure out module layout, and allocate all the memory. */
-        mod = layout_and_allocate(&info);
+        mod = layout_and_allocate(info);
         if (IS_ERR(mod)) {
                 err = PTR_ERR(mod);
                 goto free_copy;
         }
 
 #ifdef CONFIG_MODULE_SIG
-        mod->sig_ok = info.sig_ok;
+        mod->sig_ok = info->sig_ok;
         if (!mod->sig_ok)
                 add_taint_module(mod, TAINT_FORCED_MODULE);
 #endif
@@ -2983,25 +3111,25 @@ static struct module *load_module(void __user *umod,
 
         /* Now we've got everything in the final locations, we can
          * find optional sections. */
-        find_module_sections(mod, &info);
+        find_module_sections(mod, info);
 
         err = check_module_license_and_versions(mod);
         if (err)
                 goto free_unload;
 
         /* Set up MODINFO_ATTR fields */
-        setup_modinfo(mod, &info);
+        setup_modinfo(mod, info);
 
         /* Fix up syms, so that st_value is a pointer to location. */
-        err = simplify_symbols(mod, &info);
+        err = simplify_symbols(mod, info);
         if (err < 0)
                 goto free_modinfo;
 
-        err = apply_relocations(mod, &info);
+        err = apply_relocations(mod, info);
         if (err < 0)
                 goto free_modinfo;
 
-        err = post_relocation(mod, &info);
+        err = post_relocation(mod, info);
         if (err < 0)
                 goto free_modinfo;
 
@@ -3041,14 +3169,14 @@ again:
         }
 
         /* This has to be done once we're sure module name is unique. */
-        dynamic_debug_setup(info.debug, info.num_debug);
+        dynamic_debug_setup(info->debug, info->num_debug);
 
         /* Find duplicate symbols */
         err = verify_export_symbols(mod);
         if (err < 0)
                 goto ddebug;
 
-        module_bug_finalize(info.hdr, info.sechdrs, mod);
+        module_bug_finalize(info->hdr, info->sechdrs, mod);
         list_add_rcu(&mod->list, &modules);
         mutex_unlock(&module_mutex);
 
@@ -3059,16 +3187,17 @@ again:
                 goto unlink;
 
         /* Link in to syfs. */
-        err = mod_sysfs_setup(mod, &info, mod->kp, mod->num_kp);
+        err = mod_sysfs_setup(mod, info, mod->kp, mod->num_kp);
         if (err < 0)
                 goto unlink;
 
         /* Get rid of temporary copy. */
-        free_copy(&info);
+        free_copy(info);
 
         /* Done! */
         trace_module_load(mod);
-        return mod;
+
+        return do_init_module(mod);
 
  unlink:
         mutex_lock(&module_mutex);
@@ -3077,7 +3206,7 @@ again:
         module_bug_cleanup(mod);
         wake_up_all(&module_wq);
  ddebug:
-        dynamic_debug_remove(info.debug);
+        dynamic_debug_remove(info->debug);
  unlock:
         mutex_unlock(&module_mutex);
         synchronize_sched();
@@ -3089,106 +3218,48 @@ again:
  free_unload:
         module_unload_free(mod);
  free_module:
-        module_deallocate(mod, &info);
+        module_deallocate(mod, info);
  free_copy:
-        free_copy(&info);
-        return ERR_PTR(err);
-}
-
-/* Call module constructors. */
-static void do_mod_ctors(struct module *mod)
-{
-#ifdef CONFIG_CONSTRUCTORS
-        unsigned long i;
-
-        for (i = 0; i < mod->num_ctors; i++)
-                mod->ctors[i]();
-#endif
+        free_copy(info);
+        return err;
 }
 
-/* This is where the real work happens */
 SYSCALL_DEFINE3(init_module, void __user *, umod,
                 unsigned long, len, const char __user *, uargs)
 {
-        struct module *mod;
-        int ret = 0;
-
-        /* Must have permission */
-        if (!capable(CAP_SYS_MODULE) || modules_disabled)
-                return -EPERM;
+        int err;
+        struct load_info info = { };
 
-        /* Do all the hard work */
-        mod = load_module(umod, len, uargs);
-        if (IS_ERR(mod))
-                return PTR_ERR(mod);
+        err = may_init_module();
+        if (err)
+                return err;
 
-        blocking_notifier_call_chain(&module_notify_list,
-                        MODULE_STATE_COMING, mod);
+        pr_debug("init_module: umod=%p, len=%lu, uargs=%p\n",
+               umod, len, uargs);
 
-        /* Set RO and NX regions for core */
-        set_section_ro_nx(mod->module_core,
-                                mod->core_text_size,
-                                mod->core_ro_size,
-                                mod->core_size);
+        err = copy_module_from_user(umod, len, &info);
+        if (err)
+                return err;
 
-        /* Set RO and NX regions for init */
-        set_section_ro_nx(mod->module_init,
-                                mod->init_text_size,
-                                mod->init_ro_size,
-                                mod->init_size);
+        return load_module(&info, uargs);
+}
 
-        do_mod_ctors(mod);
-        /* Start the module */
-        if (mod->init != NULL)
-                ret = do_one_initcall(mod->init);
-        if (ret < 0) {
-                /* Init routine failed: abort.  Try to protect us from
-                   buggy refcounters. */
-                mod->state = MODULE_STATE_GOING;
-                synchronize_sched();
-                module_put(mod);
-                blocking_notifier_call_chain(&module_notify_list,
-                                             MODULE_STATE_GOING, mod);
-                free_module(mod);
-                wake_up_all(&module_wq);
-                return ret;
-        }
-        if (ret > 0) {
-                printk(KERN_WARNING
-"%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
-"%s: loading module anyway...\n",
-                       __func__, mod->name, ret,
-                       __func__);
-                dump_stack();
-        }
+SYSCALL_DEFINE2(finit_module, int, fd, const char __user *, uargs)
+{
+        int err;
+        struct load_info info = { };
 
-        /* Now it's a first class citizen! */
-        mod->state = MODULE_STATE_LIVE;
-        blocking_notifier_call_chain(&module_notify_list,
-                                     MODULE_STATE_LIVE, mod);
+        err = may_init_module();
+        if (err)
+                return err;
 
-        /* We need to finish all async code before the module init sequence is done */
-        async_synchronize_full();
+        pr_debug("finit_module: fd=%d, uargs=%p\n", fd, uargs);
 
-        mutex_lock(&module_mutex);
-        /* Drop initial reference. */
-        module_put(mod);
-        trim_init_extable(mod);
-#ifdef CONFIG_KALLSYMS
-        mod->num_symtab = mod->core_num_syms;
-        mod->symtab = mod->core_symtab;
-        mod->strtab = mod->core_strtab;
-#endif
-        unset_module_init_ro_nx(mod);
-        module_free(mod, mod->module_init);
-        mod->module_init = NULL;
-        mod->init_size = 0;
-        mod->init_ro_size = 0;
-        mod->init_text_size = 0;
-        mutex_unlock(&module_mutex);
-        wake_up_all(&module_wq);
+        err = copy_module_from_fd(fd, &info);
+        if (err)
+                return err;
 
-        return 0;
+        return load_module(&info, uargs);
 }
 
 static inline int within(unsigned long addr, void *start, unsigned long size)
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index dbff751e4086..395084d4ce16 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -25,6 +25,7 @@ cond_syscall(sys_swapoff);
 cond_syscall(sys_kexec_load);
 cond_syscall(compat_sys_kexec_load);
 cond_syscall(sys_init_module);
+cond_syscall(sys_finit_module);
 cond_syscall(sys_delete_module);
 cond_syscall(sys_socketpair);
 cond_syscall(sys_bind);