int check_unsafe_exec(struct linux_binprm *bprm)
{
struct task_struct *p = current, *t;
- unsigned long flags;
unsigned n_fs;
int res = 0;
n_fs = 1;
write_lock(&p->fs->lock);
- lock_task_sighand(p, &flags);
+ rcu_read_lock();
for (t = next_thread(p); t != p; t = next_thread(t)) {
if (t->fs == p->fs)
n_fs++;
}
+ rcu_read_unlock();
if (p->fs->users > n_fs) {
bprm->unsafe |= LSM_UNSAFE_SHARE;
} else {
- if (p->fs->in_exec)
- res = -EAGAIN;
- p->fs->in_exec = 1;
+ res = -EAGAIN;
+ if (!p->fs->in_exec) {
+ p->fs->in_exec = 1;
+ res = 1;
+ }
}
-
- unlock_task_sighand(p, &flags);
write_unlock(&p->fs->lock);
return res;
struct linux_binprm *bprm;
struct file *file;
struct files_struct *displaced;
+ bool clear_in_exec;
int retval;
retval = unshare_files(&displaced);
goto out_unlock;
retval = check_unsafe_exec(bprm);
- if (retval)
+ if (retval < 0)
goto out_unlock;
+ clear_in_exec = retval;
file = open_exec(filename);
retval = PTR_ERR(file);
goto out;
/* execve succeeded */
- write_lock(¤t->fs->lock);
current->fs->in_exec = 0;
- write_unlock(¤t->fs->lock);
current->in_execve = 0;
mutex_unlock(¤t->cred_exec_mutex);
acct_update_integrals(current);
}
out_unmark:
- write_lock(¤t->fs->lock);
- current->fs->in_exec = 0;
- write_unlock(¤t->fs->lock);
+ if (clear_in_exec)
+ current->fs->in_exec = 0;
out_unlock:
current->in_execve = 0;