From 41126226e186d92a45ed664e546abb5204588359 Mon Sep 17 00:00:00 2001 From: Miloslav Trmac Date: Fri, 18 Apr 2008 13:30:14 -0700 Subject: [patch 1/2] audit: let userspace fully control TTY input auditing Remove the code that automatically disables TTY input auditing in processes that open TTYs when they have no other TTY open; this heuristic was intended to automatically handle daemons, but it has false positives (e.g. with sshd) that make it impossible to control TTY input auditing from a PAM module. With this patch, TTY input auditing is controlled from user-space only. On the other hand, not even for daemons does it make sense to audit "input" from PTY masters; this data was produced by a program writing to the PTY slave, and does not represent data entered by the user. Signed-off-by: Miloslav Trmac Cc: Al Viro Cc: David Woodhouse Signed-off-by: Andrew Morton Signed-off-by: Al Viro --- drivers/char/tty_audit.c | 54 ++++-------------------------------------------- 1 file changed, 4 insertions(+), 50 deletions(-) (limited to 'drivers/char/tty_audit.c') diff --git a/drivers/char/tty_audit.c b/drivers/char/tty_audit.c index caeedd12d49..6342b0534f4 100644 --- a/drivers/char/tty_audit.c +++ b/drivers/char/tty_audit.c @@ -233,6 +233,10 @@ void tty_audit_add_data(struct tty_struct *tty, unsigned char *data, if (unlikely(size == 0)) return; + if (tty->driver->type == TTY_DRIVER_TYPE_PTY + && tty->driver->subtype == PTY_TYPE_MASTER) + return; + buf = tty_audit_buf_get(tty); if (!buf) return; @@ -295,53 +299,3 @@ void tty_audit_push(struct tty_struct *tty) tty_audit_buf_put(buf); } } - -/** - * tty_audit_opening - A TTY is being opened. - * - * As a special hack, tasks that close all their TTYs and open new ones - * are assumed to be system daemons (e.g. getty) and auditing is - * automatically disabled for them. - */ -void tty_audit_opening(void) -{ - int disable; - - disable = 1; - spin_lock_irq(¤t->sighand->siglock); - if (current->signal->audit_tty == 0) - disable = 0; - spin_unlock_irq(¤t->sighand->siglock); - if (!disable) - return; - - task_lock(current); - if (current->files) { - struct fdtable *fdt; - unsigned i; - - /* - * We don't take a ref to the file, so we must hold ->file_lock - * instead. - */ - spin_lock(¤t->files->file_lock); - fdt = files_fdtable(current->files); - for (i = 0; i < fdt->max_fds; i++) { - struct file *filp; - - filp = fcheck_files(current->files, i); - if (filp && is_tty(filp)) { - disable = 0; - break; - } - } - spin_unlock(¤t->files->file_lock); - } - task_unlock(current); - if (!disable) - return; - - spin_lock_irq(¤t->sighand->siglock); - current->signal->audit_tty = 0; - spin_unlock_irq(¤t->sighand->siglock); -} -- cgit v1.2.3