Commit 90383cc0 authored by Kees Cook's avatar Kees Cook
Browse files

exec: Distinguish in_execve from in_exec 



Just to help distinguish the fs->in_exec flag from the current->in_execve
flag, add comments in check_unsafe_exec() and copy_fs() for more
context. Also note that in_execve is only used by TOMOYO now.

Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-mm@kvack.org
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
parent 84c39ec5

fs/exec.c

+1 −0
Original line number Diff line number Diff line
@@ -1633,6 +1633,7 @@ static void check_unsafe_exec(struct linux_binprm *bprm) 
	}

	rcu_read_unlock();



	/* "users" and "in_exec" locked for copy_fs() */

	if (p->fs->users > n_fs)

		bprm->unsafe |= LSM_UNSAFE_SHARE;

	else

include/linux/sched.h

+1 −1
Original line number Diff line number Diff line
@@ -920,7 +920,7 @@ struct task_struct { 
	unsigned			sched_rt_mutex:1;

#endif



	/* Bit to tell LSMs we're in execve(): */

	/* Bit to tell TOMOYO we're in execve(): */

	unsigned			in_execve:1;

	unsigned			in_iowait:1;

#ifndef TIF_RESTORE_SIGMASK

kernel/fork.c

+1 −0
Original line number Diff line number Diff line
@@ -1748,6 +1748,7 @@ static int copy_fs(unsigned long clone_flags, struct task_struct *tsk) 
	if (clone_flags & CLONE_FS) {

		/* tsk->fs is already what we want */

		spin_lock(&fs->lock);

		/* "users" and "in_exec" locked for check_unsafe_exec() */

		if (fs->in_exec) {

			spin_unlock(&fs->lock);

			return -EAGAIN;