1 files changed, 57 insertions, 142 deletions

diff --git a/fs/exec.c b/fs/exec.c
index 7ea097f6b341..9e81c630dfa7 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -26,6 +26,7 @@
 #include <linux/file.h>
 #include <linux/fdtable.h>
 #include <linux/mm.h>
+#include <linux/vmacache.h>
 #include <linux/stat.h>
 #include <linux/fcntl.h>
 #include <linux/swap.h>
@@ -62,7 +63,6 @@
 
 #include <trace/events/task.h>
 #include "internal.h"
-#include "coredump.h"
 
 #include <trace/events/sched.h>
 
@@ -98,6 +98,7 @@ static inline void put_binfmt(struct linux_binfmt * fmt)
 	module_put(fmt->module);
 }
 
+#ifdef CONFIG_USELIB
 /*
  * Note that a shared library must be both readable and executable due to
  * security reasons.
@@ -157,6 +158,7 @@ exit:
 out:
   	return error;
 }
+#endif /* #ifdef CONFIG_USELIB */
 
 #ifdef CONFIG_MMU
 /*
@@ -749,11 +751,10 @@ EXPORT_SYMBOL(setup_arg_pages);
 
 #endif /* CONFIG_MMU */
 
-struct file *open_exec(const char *name)
+static struct file *do_open_exec(struct filename *name)
 {
 	struct file *file;
 	int err;
-	struct filename tmp = { .name = name };
 	static const struct open_flags open_exec_flags = {
 		.open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC,
 		.acc_mode = MAY_EXEC | MAY_OPEN,
@@ -761,7 +762,7 @@ struct file *open_exec(const char *name)
 		.lookup_flags = LOOKUP_FOLLOW,
 	};
 
-	file = do_filp_open(AT_FDCWD, &tmp, &open_exec_flags);
+	file = do_filp_open(AT_FDCWD, name, &open_exec_flags);
 	if (IS_ERR(file))
 		goto out;
 
@@ -785,6 +786,12 @@ exit:
 	fput(file);
 	return ERR_PTR(err);
 }
+
+struct file *open_exec(const char *name)
+{
+	struct filename tmp = { .name = name };
+	return do_open_exec(&tmp);
+}
 EXPORT_SYMBOL(open_exec);
 
 int kernel_read(struct file *file, loff_t offset,
@@ -816,7 +823,7 @@ EXPORT_SYMBOL(read_code);
 static int exec_mmap(struct mm_struct *mm)
 {
 	struct task_struct *tsk;
-	struct mm_struct * old_mm, *active_mm;
+	struct mm_struct *old_mm, *active_mm;
 
 	/* Notify parent that we're no longer interested in the old VM */
 	tsk = current;
@@ -842,8 +849,9 @@ static int exec_mmap(struct mm_struct *mm)
 	tsk->mm = mm;
 	tsk->active_mm = mm;
 	activate_mm(active_mm, mm);
+	tsk->mm->vmacache_seqnum = 0;
+	vmacache_flush(tsk);
 	task_unlock(tsk);
-	arch_pick_mmap_layout(mm);
 	if (old_mm) {
 		up_read(&old_mm->mmap_sem);
 		BUG_ON(active_mm != old_mm);
@@ -1038,7 +1046,7 @@ EXPORT_SYMBOL_GPL(get_task_comm);
  * so that a new one can be started
  */
 
-void set_task_comm(struct task_struct *tsk, char *buf)
+void set_task_comm(struct task_struct *tsk, const char *buf)
 {
 	task_lock(tsk);
 	trace_task_rename(tsk, buf);
@@ -1047,21 +1055,6 @@ void set_task_comm(struct task_struct *tsk, char *buf)
 	perf_event_comm(tsk);
 }
 
-static void filename_to_taskname(char *tcomm, const char *fn, unsigned int len)
-{
-	int i, ch;
-
-	/* Copies the binary name from after last slash */
-	for (i = 0; (ch = *(fn++)) != '\0';) {
-		if (ch == '/')
-			i = 0; /* overwrite what we wrote */
-		else
-			if (i < len - 1)
-				tcomm[i++] = ch;
-	}
-	tcomm[i] = '\0';
-}
-
 int flush_old_exec(struct linux_binprm * bprm)
 {
 	int retval;
@@ -1075,8 +1068,6 @@ int flush_old_exec(struct linux_binprm * bprm)
 		goto out;
 
 	set_mm_exe_file(bprm->mm, bprm->file);
-
-	filename_to_taskname(bprm->tcomm, bprm->filename, sizeof(bprm->tcomm));
 	/*
 	 * Release all of the old mmap stuff
 	 */
@@ -1088,8 +1079,8 @@ int flush_old_exec(struct linux_binprm * bprm)
 	bprm->mm = NULL;		/* We're using it now */
 
 	set_fs(USER_DS);
-	current->flags &=
-		~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD | PF_NOFREEZE);
+	current->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD |
+					PF_NOFREEZE | PF_NO_SETAFFINITY);
 	flush_thread();
 	current->personality &= ~bprm->per_clear;
 
@@ -1119,7 +1110,7 @@ void setup_new_exec(struct linux_binprm * bprm)
 	else
 		set_dumpable(current->mm, suid_dumpable);
 
-	set_task_comm(current, bprm->tcomm);
+	set_task_comm(current, kbasename(bprm->filename));
 
 	/* Set the new mm task size. We have to do that late because it may
 	 * depend on TIF_32BIT which is only updated in flush_thread() on
@@ -1139,9 +1130,7 @@ void setup_new_exec(struct linux_binprm * bprm)
 
 	/* An exec changes our domain. We are no longer part of the thread
 	   group */
-
 	current->self_exec_id++;
-			
 	flush_signal_handlers(current, 0);
 	do_close_on_exec(current->files);
 }
@@ -1166,13 +1155,17 @@ int prepare_bprm_creds(struct linux_binprm *bprm)
 	return -ENOMEM;
 }
 
-void free_bprm(struct linux_binprm *bprm)
+static void free_bprm(struct linux_binprm *bprm)
 {
 	free_arg_pages(bprm);
 	if (bprm->cred) {
 		mutex_unlock(&current->signal->cred_guard_mutex);
 		abort_creds(bprm->cred);
 	}
+	if (bprm->file) {
+		allow_write_access(bprm->file);
+		fput(bprm->file);
+	}
 	/* If a binfmt changed the interp, free it. */
 	if (bprm->interp != bprm->filename)
 		kfree(bprm->interp);
@@ -1224,11 +1217,10 @@ EXPORT_SYMBOL(install_exec_creds);
  * - the caller must hold ->cred_guard_mutex to protect against
  *   PTRACE_ATTACH
  */
-static int check_unsafe_exec(struct linux_binprm *bprm)
+static void check_unsafe_exec(struct linux_binprm *bprm)
 {
 	struct task_struct *p = current, *t;
 	unsigned n_fs;
-	int res = 0;
 
 	if (p->ptrace) {
 		if (p->ptrace & PT_PTRACE_CAP)
@@ -1244,31 +1236,25 @@ static int check_unsafe_exec(struct linux_binprm *bprm)
 	if (current->no_new_privs)
 		bprm->unsafe |= LSM_UNSAFE_NO_NEW_PRIVS;
 
+	t = p;
 	n_fs = 1;
 	spin_lock(&p->fs->lock);
 	rcu_read_lock();
-	for (t = next_thread(p); t != p; t = next_thread(t)) {
+	while_each_thread(p, t) {
 		if (t->fs == p->fs)
 			n_fs++;
 	}
 	rcu_read_unlock();
 
-	if (p->fs->users > n_fs) {
+	if (p->fs->users > n_fs)
 		bprm->unsafe |= LSM_UNSAFE_SHARE;
-	} else {
-		res = -EAGAIN;
-		if (!p->fs->in_exec) {
-			p->fs->in_exec = 1;
-			res = 1;
-		}
-	}
+	else
+		p->fs->in_exec = 1;
 	spin_unlock(&p->fs->lock);
-
-	return res;
 }
 
-/* 
- * Fill the binprm structure from the inode. 
+/*
+ * Fill the binprm structure from the inode.
  * Check permissions, then read the first 128 (BINPRM_BUF_SIZE) bytes
  *
  * This may be called multiple times for binary chains (scripts for example).
@@ -1430,14 +1416,7 @@ static int exec_binprm(struct linux_binprm *bprm)
 		audit_bprm(bprm);
 		trace_sched_process_exec(current, old_pid, bprm);
 		ptrace_event(PTRACE_EVENT_EXEC, old_vpid);
-		current->did_exec = 1;
 		proc_exec_connector(current);
-
-		if (bprm->file) {
-			allow_write_access(bprm->file);
-			fput(bprm->file);
-			bprm->file = NULL; /* to catch use-after-free */
-		}
 	}
 
 	return ret;
@@ -1446,16 +1425,18 @@ static int exec_binprm(struct linux_binprm *bprm)
 /*
  * sys_execve() executes a new program.
  */
-static int do_execve_common(const char *filename,
+static int do_execve_common(struct filename *filename,
 				struct user_arg_ptr argv,
 				struct user_arg_ptr envp)
 {
 	struct linux_binprm *bprm;
 	struct file *file;
 	struct files_struct *displaced;
-	bool clear_in_exec;
 	int retval;
 
+	if (IS_ERR(filename))
+		return PTR_ERR(filename);
+
 	/*
 	 * We move the actual failure in case of RLIMIT_NPROC excess from
 	 * set*uid() to execve() because too many poorly written programs
@@ -1485,13 +1466,10 @@ static int do_execve_common(const char *filename,
 	if (retval)
 		goto out_free;
 
-	retval = check_unsafe_exec(bprm);
-	if (retval < 0)
-		goto out_free;
-	clear_in_exec = retval;
+	check_unsafe_exec(bprm);
 	current->in_execve = 1;
 
-	file = open_exec(filename);
+	file = do_open_exec(filename);
 	retval = PTR_ERR(file);
 	if (IS_ERR(file))
 		goto out_unmark;
@@ -1499,12 +1477,11 @@ static int do_execve_common(const char *filename,
 	sched_exec();
 
 	bprm->file = file;
-	bprm->filename = filename;
-	bprm->interp = filename;
+	bprm->filename = bprm->interp = filename->name;
 
 	retval = bprm_mm_init(bprm);
 	if (retval)
-		goto out_file;
+		goto out_unmark;
 
 	bprm->argc = count(argv, MAX_ARG_STRINGS);
 	if ((retval = bprm->argc) < 0)
@@ -1541,6 +1518,7 @@ static int do_execve_common(const char *filename,
 	acct_update_integrals(current);
 	task_numa_free(current);
 	free_bprm(bprm);
+	putname(filename);
 	if (displaced)
 		put_files_struct(displaced);
 	return retval;
@@ -1551,15 +1529,8 @@ out:
 		mmput(bprm->mm);
 	}
 
-out_file:
-	if (bprm->file) {
-		allow_write_access(bprm->file);
-		fput(bprm->file);
-	}
-
 out_unmark:
-	if (clear_in_exec)
-		current->fs->in_exec = 0;
+	current->fs->in_exec = 0;
 	current->in_execve = 0;
 
 out_free:
@@ -1569,10 +1540,11 @@ out_files:
 	if (displaced)
 		reset_files_struct(displaced);
 out_ret:
+	putname(filename);
 	return retval;
 }
 
-int do_execve(const char *filename,
+int do_execve(struct filename *filename,
 	const char __user *const __user *__argv,
 	const char __user *const __user *__envp)
 {
@@ -1582,7 +1554,7 @@ int do_execve(const char *filename,
 }
 
 #ifdef CONFIG_COMPAT
-static int compat_do_execve(const char *filename,
+static int compat_do_execve(struct filename *filename,
 	const compat_uptr_t __user *__argv,
 	const compat_uptr_t __user *__envp)
 {
@@ -1609,67 +1581,22 @@ void set_binfmt(struct linux_binfmt *new)
 	if (new)
 		__module_get(new->module);
 }
-
 EXPORT_SYMBOL(set_binfmt);
 
 /*
- * set_dumpable converts traditional three-value dumpable to two flags and
- * stores them into mm->flags.  It modifies lower two bits of mm->flags, but
- * these bits are not changed atomically.  So get_dumpable can observe the
- * intermediate state.  To avoid doing unexpected behavior, get get_dumpable
- * return either old dumpable or new one by paying attention to the order of
- * modifying the bits.
- *
- * dumpable |   mm->flags (binary)
- * old  new | initial interim  final
- * ---------+-----------------------
- *  0    1  |   00      01      01
- *  0    2  |   00      10(*)   11
- *  1    0  |   01      00      00
- *  1    2  |   01      11      11
- *  2    0  |   11      10(*)   00
- *  2    1  |   11      11      01
- *
- * (*) get_dumpable regards interim value of 10 as 11.
+ * set_dumpable stores three-value SUID_DUMP_* into mm->flags.
  */
 void set_dumpable(struct mm_struct *mm, int value)
 {
-	switch (value) {
-	case SUID_DUMP_DISABLE:
-		clear_bit(MMF_DUMPABLE, &mm->flags);
-		smp_wmb();
-		clear_bit(MMF_DUMP_SECURELY, &mm->flags);
-		break;
-	case SUID_DUMP_USER:
-		set_bit(MMF_DUMPABLE, &mm->flags);
-		smp_wmb();
-		clear_bit(MMF_DUMP_SECURELY, &mm->flags);
-		break;
-	case SUID_DUMP_ROOT:
-		set_bit(MMF_DUMP_SECURELY, &mm->flags);
-		smp_wmb();
-		set_bit(MMF_DUMPABLE, &mm->flags);
-		break;
-	}
-}
+	unsigned long old, new;
 
-int __get_dumpable(unsigned long mm_flags)
-{
-	int ret;
-
-	ret = mm_flags & MMF_DUMPABLE_MASK;
-	return (ret > SUID_DUMP_USER) ? SUID_DUMP_ROOT : ret;
-}
+	if (WARN_ON((unsigned)value > SUID_DUMP_ROOT))
+		return;
 
-/*
- * This returns the actual value of the suid_dumpable flag. For things
- * that are using this for checking for privilege transitions, it must
- * test against SUID_DUMP_USER rather than treating it as a boolean
- * value.
- */
-int get_dumpable(struct mm_struct *mm)
-{
-	return __get_dumpable(mm->flags);
+	do {
+		old = ACCESS_ONCE(mm->flags);
+		new = (old & ~MMF_DUMPABLE_MASK) | value;
+	} while (cmpxchg(&mm->flags, old, new) != old);
 }
 
 SYSCALL_DEFINE3(execve,
@@ -1677,25 +1604,13 @@ SYSCALL_DEFINE3(execve,
 		const char __user *const __user *, argv,
 		const char __user *const __user *, envp)
 {
-	struct filename *path = getname(filename);
-	int error = PTR_ERR(path);
-	if (!IS_ERR(path)) {
-		error = do_execve(path->name, argv, envp);
-		putname(path);
-	}
-	return error;
+	return do_execve(getname(filename), argv, envp);
 }
 #ifdef CONFIG_COMPAT
-asmlinkage long compat_sys_execve(const char __user * filename,
-	const compat_uptr_t __user * argv,
-	const compat_uptr_t __user * envp)
+COMPAT_SYSCALL_DEFINE3(execve, const char __user *, filename,
+	const compat_uptr_t __user *, argv,
+	const compat_uptr_t __user *, envp)
 {
-	struct filename *path = getname(filename);
-	int error = PTR_ERR(path);
-	if (!IS_ERR(path)) {
-		error = compat_do_execve(path->name, argv, envp);
-		putname(path);
-	}
-	return error;
+	return compat_do_execve(getname(filename), argv, envp);
 }
 #endif