| From bc5269ca765057a1b762e79a1cfd267cd7bf1c46 Mon Sep 17 00:00:00 2001 |
| From: George Kennedy <george.kennedy@oracle.com> |
| Date: Fri, 31 Jul 2020 12:33:12 -0400 |
| Subject: vt_ioctl: change VT_RESIZEX ioctl to check for error return from vc_resize() |
| |
| From: George Kennedy <george.kennedy@oracle.com> |
| |
| commit bc5269ca765057a1b762e79a1cfd267cd7bf1c46 upstream. |
| |
| vc_resize() can return with an error after failure. Change VT_RESIZEX ioctl |
| to save struct vc_data values that are modified and restore the original |
| values in case of error. |
| |
| Signed-off-by: George Kennedy <george.kennedy@oracle.com> |
| Cc: stable <stable@vger.kernel.org> |
| Reported-by: syzbot+38a3699c7eaf165b97a6@syzkaller.appspotmail.com |
| Link: https://lore.kernel.org/r/1596213192-6635-2-git-send-email-george.kennedy@oracle.com |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/tty/vt/vt_ioctl.c | 12 +++++++++++- |
| 1 file changed, 11 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/tty/vt/vt_ioctl.c |
| +++ b/drivers/tty/vt/vt_ioctl.c |
| @@ -896,12 +896,22 @@ int vt_ioctl(struct tty_struct *tty, |
| console_lock(); |
| vcp = vc_cons[i].d; |
| if (vcp) { |
| + int ret; |
| + int save_scan_lines = vcp->vc_scan_lines; |
| + int save_font_height = vcp->vc_font.height; |
| + |
| if (v.v_vlin) |
| vcp->vc_scan_lines = v.v_vlin; |
| if (v.v_clin) |
| vcp->vc_font.height = v.v_clin; |
| vcp->vc_resize_user = 1; |
| - vc_resize(vcp, v.v_cols, v.v_rows); |
| + ret = vc_resize(vcp, v.v_cols, v.v_rows); |
| + if (ret) { |
| + vcp->vc_scan_lines = save_scan_lines; |
| + vcp->vc_font.height = save_font_height; |
| + console_unlock(); |
| + return ret; |
| + } |
| } |
| console_unlock(); |
| } |
