Merge branch 'next' into for-linus

Prepare first set of updates for 3.10 merge window.

1 files changed, 47 insertions, 62 deletions

diff --git a/fs/exec.c b/fs/exec.c
index 0039055b1fc6..a96a4885bbbf 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -123,7 +123,7 @@ SYSCALL_DEFINE1(uselib, const char __user *, library)
 		goto out;
 
 	error = -EINVAL;
-	if (!S_ISREG(file->f_path.dentry->d_inode->i_mode))
+	if (!S_ISREG(file_inode(file)->i_mode))
 		goto exit;
 
 	error = -EACCES;
@@ -355,7 +355,7 @@ static bool valid_arg_len(struct linux_binprm *bprm, long len)
  * flags, permissions, and offset, so we use temporary values.  We'll update
  * them later in setup_arg_pages().
  */
-int bprm_mm_init(struct linux_binprm *bprm)
+static int bprm_mm_init(struct linux_binprm *bprm)
 {
 	int err;
 	struct mm_struct *mm = NULL;
@@ -434,8 +434,9 @@ static int count(struct user_arg_ptr argv, int max)
 			if (IS_ERR(p))
 				return -EFAULT;
 
-			if (i++ >= max)
+			if (i >= max)
 				return -E2BIG;
+			++i;
 
 			if (fatal_signal_pending(current))
 				return -ERESTARTNOHAND;
@@ -763,7 +764,7 @@ struct file *open_exec(const char *name)
 		goto out;
 
 	err = -EACCES;
-	if (!S_ISREG(file->f_path.dentry->d_inode->i_mode))
+	if (!S_ISREG(file_inode(file)->i_mode))
 		goto exit;
 
 	if (file->f_path.mnt->mnt_flags & MNT_NOEXEC)
@@ -1097,7 +1098,7 @@ EXPORT_SYMBOL(flush_old_exec);
 
 void would_dump(struct linux_binprm *bprm, struct file *file)
 {
-	if (inode_permission(file->f_path.dentry->d_inode, MAY_READ) < 0)
+	if (inode_permission(file_inode(file), MAY_READ) < 0)
 		bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
 }
 EXPORT_SYMBOL(would_dump);
@@ -1110,7 +1111,7 @@ void setup_new_exec(struct linux_binprm * bprm)
 	current->sas_ss_sp = current->sas_ss_size = 0;
 
 	if (uid_eq(current_euid(), current_uid()) && gid_eq(current_egid(), current_gid()))
-		set_dumpable(current->mm, SUID_DUMPABLE_ENABLED);
+		set_dumpable(current->mm, SUID_DUMP_USER);
 	else
 		set_dumpable(current->mm, suid_dumpable);
 
@@ -1175,9 +1176,24 @@ void free_bprm(struct linux_binprm *bprm)
 		mutex_unlock(&current->signal->cred_guard_mutex);
 		abort_creds(bprm->cred);
 	}
+	/* If a binfmt changed the interp, free it. */
+	if (bprm->interp != bprm->filename)
+		kfree(bprm->interp);
 	kfree(bprm);
 }
 
+int bprm_change_interp(char *interp, struct linux_binprm *bprm)
+{
+	/* If a binfmt changed the interp, free it first. */
+	if (bprm->interp != bprm->filename)
+		kfree(bprm->interp);
+	bprm->interp = kstrdup(interp, GFP_KERNEL);
+	if (!bprm->interp)
+		return -ENOMEM;
+	return 0;
+}
+EXPORT_SYMBOL(bprm_change_interp);
+
 /*
  * install the new credentials for this executable
  */
@@ -1254,7 +1270,7 @@ static int check_unsafe_exec(struct linux_binprm *bprm)
 int prepare_binprm(struct linux_binprm *bprm)
 {
 	umode_t mode;
-	struct inode * inode = bprm->file->f_path.dentry->d_inode;
+	struct inode * inode = file_inode(bprm->file);
 	int retval;
 
 	mode = inode->i_mode;
@@ -1266,14 +1282,13 @@ int prepare_binprm(struct linux_binprm *bprm)
 	bprm->cred->egid = current_egid();
 
 	if (!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) &&
-	    !current->no_new_privs) {
+	    !current->no_new_privs &&
+	    kuid_has_mapping(bprm->cred->user_ns, inode->i_uid) &&
+	    kgid_has_mapping(bprm->cred->user_ns, inode->i_gid)) {
 		/* Set-uid? */
 		if (mode & S_ISUID) {
-			if (!kuid_has_mapping(bprm->cred->user_ns, inode->i_uid))
-				return -EPERM;
 			bprm->per_clear |= PER_CLEAR_ON_SETID;
 			bprm->cred->euid = inode->i_uid;
-
 		}
 
 		/* Set-gid? */
@@ -1283,8 +1298,6 @@ int prepare_binprm(struct linux_binprm *bprm)
 		 * executable.
 		 */
 		if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
-			if (!kgid_has_mapping(bprm->cred->user_ns, inode->i_gid))
-				return -EPERM;
 			bprm->per_clear |= PER_CLEAR_ON_SETID;
 			bprm->cred->egid = inode->i_gid;
 		}
@@ -1349,13 +1362,17 @@ EXPORT_SYMBOL(remove_arg_zero);
 /*
  * cycle the list of binary formats handler, until one recognizes the image
  */
-int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
+int search_binary_handler(struct linux_binprm *bprm)
 {
 	unsigned int depth = bprm->recursion_depth;
 	int try,retval;
 	struct linux_binfmt *fmt;
 	pid_t old_pid, old_vpid;
 
+	/* This allows 4 levels of binfmt rewrites before failing hard. */
+	if (depth > 5)
+		return -ELOOP;
+
 	retval = security_bprm_check(bprm);
 	if (retval)
 		return retval;
@@ -1374,18 +1391,14 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
 	for (try=0; try<2; try++) {
 		read_lock(&binfmt_lock);
 		list_for_each_entry(fmt, &formats, lh) {
-			int (*fn)(struct linux_binprm *, struct pt_regs *) = fmt->load_binary;
+			int (*fn)(struct linux_binprm *) = fmt->load_binary;
 			if (!fn)
 				continue;
 			if (!try_module_get(fmt->module))
 				continue;
 			read_unlock(&binfmt_lock);
-			retval = fn(bprm, regs);
-			/*
-			 * Restore the depth counter to its starting value
-			 * in this call, so we don't have to rely on every
-			 * load_binary function to restore it on return.
-			 */
+			bprm->recursion_depth = depth + 1;
+			retval = fn(bprm);
 			bprm->recursion_depth = depth;
 			if (retval >= 0) {
 				if (depth == 0) {
@@ -1439,8 +1452,7 @@ EXPORT_SYMBOL(search_binary_handler);
  */
 static int do_execve_common(const char *filename,
 				struct user_arg_ptr argv,
-				struct user_arg_ptr envp,
-				struct pt_regs *regs)
+				struct user_arg_ptr envp)
 {
 	struct linux_binprm *bprm;
 	struct file *file;
@@ -1524,7 +1536,7 @@ static int do_execve_common(const char *filename,
 	if (retval < 0)
 		goto out;
 
-	retval = search_binary_handler(bprm,regs);
+	retval = search_binary_handler(bprm);
 	if (retval < 0)
 		goto out;
 
@@ -1566,19 +1578,17 @@ out_ret:
 
 int do_execve(const char *filename,
 	const char __user *const __user *__argv,
-	const char __user *const __user *__envp,
-	struct pt_regs *regs)
+	const char __user *const __user *__envp)
 {
 	struct user_arg_ptr argv = { .ptr.native = __argv };
 	struct user_arg_ptr envp = { .ptr.native = __envp };
-	return do_execve_common(filename, argv, envp, regs);
+	return do_execve_common(filename, argv, envp);
 }
 
 #ifdef CONFIG_COMPAT
-int compat_do_execve(const char *filename,
+static int compat_do_execve(const char *filename,
 	const compat_uptr_t __user *__argv,
-	const compat_uptr_t __user *__envp,
-	struct pt_regs *regs)
+	const compat_uptr_t __user *__envp)
 {
 	struct user_arg_ptr argv = {
 		.is_compat = true,
@@ -1588,7 +1598,7 @@ int compat_do_execve(const char *filename,
 		.is_compat = true,
 		.ptr.compat = __envp,
 	};
-	return do_execve_common(filename, argv, envp, regs);
+	return do_execve_common(filename, argv, envp);
 }
 #endif
 
@@ -1629,17 +1639,17 @@ EXPORT_SYMBOL(set_binfmt);
 void set_dumpable(struct mm_struct *mm, int value)
 {
 	switch (value) {
-	case SUID_DUMPABLE_DISABLED:
+	case SUID_DUMP_DISABLE:
 		clear_bit(MMF_DUMPABLE, &mm->flags);
 		smp_wmb();
 		clear_bit(MMF_DUMP_SECURELY, &mm->flags);
 		break;
-	case SUID_DUMPABLE_ENABLED:
+	case SUID_DUMP_USER:
 		set_bit(MMF_DUMPABLE, &mm->flags);
 		smp_wmb();
 		clear_bit(MMF_DUMP_SECURELY, &mm->flags);
 		break;
-	case SUID_DUMPABLE_SAFE:
+	case SUID_DUMP_ROOT:
 		set_bit(MMF_DUMP_SECURELY, &mm->flags);
 		smp_wmb();
 		set_bit(MMF_DUMPABLE, &mm->flags);
@@ -1652,7 +1662,7 @@ int __get_dumpable(unsigned long mm_flags)
 	int ret;
 
 	ret = mm_flags & MMF_DUMPABLE_MASK;
-	return (ret > SUID_DUMPABLE_ENABLED) ? SUID_DUMPABLE_SAFE : ret;
+	return (ret > SUID_DUMP_USER) ? SUID_DUMP_ROOT : ret;
 }
 
 int get_dumpable(struct mm_struct *mm)
@@ -1660,7 +1670,6 @@ int get_dumpable(struct mm_struct *mm)
 	return __get_dumpable(mm->flags);
 }
 
-#ifdef __ARCH_WANT_SYS_EXECVE
 SYSCALL_DEFINE3(execve,
 		const char __user *, filename,
 		const char __user *const __user *, argv,
@@ -1669,7 +1678,7 @@ SYSCALL_DEFINE3(execve,
 	struct filename *path = getname(filename);
 	int error = PTR_ERR(path);
 	if (!IS_ERR(path)) {
-		error = do_execve(path->name, argv, envp, current_pt_regs());
+		error = do_execve(path->name, argv, envp);
 		putname(path);
 	}
 	return error;
@@ -1682,33 +1691,9 @@ asmlinkage long compat_sys_execve(const char __user * filename,
 	struct filename *path = getname(filename);
 	int error = PTR_ERR(path);
 	if (!IS_ERR(path)) {
-		error = compat_do_execve(path->name, argv, envp,
-							current_pt_regs());
+		error = compat_do_execve(path->name, argv, envp);
 		putname(path);
 	}
 	return error;
 }
 #endif
-#endif
-
-#ifdef __ARCH_WANT_KERNEL_EXECVE
-int kernel_execve(const char *filename,
-		  const char *const argv[],
-		  const char *const envp[])
-{
-	struct pt_regs *p = current_pt_regs();
-	int ret;
-
-	ret = do_execve(filename,
-			(const char __user *const __user *)argv,
-			(const char __user *const __user *)envp, p);
-	if (ret < 0)
-		return ret;
-
-	/*
-	 * We were successful.  We won't be returning to our caller, but
-	 * instead to user space by manipulating the kernel stack.
-	 */
-	ret_from_kernel_execve(p);
-}
-#endif