vt_ioctl: change VT_RESIZEX ioctl to check for error return from vc_resize()

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>
This commit is contained in:
George Kennedy 2020-07-31 12:33:12 -04:00 committed by Greg Kroah-Hartman
parent 39b3cffb8c
commit bc5269ca76
1 changed files with 11 additions and 1 deletions

View File

@ -806,12 +806,22 @@ static int vt_resizex(struct vc_data *vc, struct vt_consize __user *cs)
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();
}