Messages in this thread |  | | From | Alexander Stein <> | Subject | Re: [PATCH] Clean console safely | Date | Wed, 13 Apr 2011 17:32:37 +0200 |
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Hi,
On Wednesday 13 April 2011, 17:18:04 Chris Ball wrote: > On Wed, Apr 13 2011, Petr Písař wrote: > > Traditional \E[2J sequence erases console display but scroll-back > > buffer and underlying device (frame) buffer keep data that can be > > accessed by scrolling console back. > > > > This patch introduce new \E[J parameter 3 that allows to scramble > > scroll-back buffer explicitly. Session locking programs (screen, > > vlock) can use it to prevent attacker to browse locked console > > history. > > > > Signed-off-by: Petr Písař <ppisar@redhat.com> > > --- > > > > drivers/tty/vt/vt.c | 6 ++++++ > > 1 files changed, 6 insertions(+), 0 deletions(-) > > > > diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c > > index 4bea1ef..fe96a1f 100644 > > --- a/drivers/tty/vt/vt.c > > +++ b/drivers/tty/vt/vt.c > > @@ -1197,6 +1197,12 @@ static void csi_J(struct vc_data *vc, int vpar) > > > > vc->vc_x + 1); > > > > } > > break; > > > > + case 3: /* erase scroll-back buffer (and whole display) */ > > + scr_memsetw(vc->vc_screenbuf, vc->vc_video_erase_char, > > + vc->vc_screenbuf_size >> 1); > > + set_origin(vc); > > + if (CON_IS_VISIBLE(vc)) > > + update_screen(vc); > > > > case 2: /* erase whole display */ > > > > count = vc->vc_cols * vc->vc_rows; > > start = (unsigned short *)vc->vc_origin; > > Nitpick: the cases were ordered before -- 3 should go after 2.
Not if the fall-through is intended.
Alexander -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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