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| author | Petr Písař <ppisar@redhat.com> | 2011-04-15 10:08:08 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-04-19 16:33:37 -0700 |
| commit | f8df13e0a901fe55631fed66562369b4dba40f8b (patch) | |
| tree | 105031898b999a9da275a7aa32b5d67733d5b849 | |
| parent | d94206028854ba4c891004cecdbb2e220bf277bb (diff) | |
| download | blackbird-obmc-linux-f8df13e0a901fe55631fed66562369b4dba40f8b.tar.gz blackbird-obmc-linux-f8df13e0a901fe55631fed66562369b4dba40f8b.zip | |
tty: Clean console safely
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/tty/vt/vt.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index a48da2063060..b3915b7ad3e2 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -1193,6 +1193,13 @@ 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); + /* fall through */ case 2: /* erase whole display */ count = vc->vc_cols * vc->vc_rows; start = (unsigned short *)vc->vc_origin; |
