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@xxxxxxxxxx>
Reported-by: syzbot+38a3699c7eaf165b97a6@xxxxxxxxxxxxxxxxxxxxxxxxx
---
Version of patch available for Mainline also.
drivers/tty/vt/vt_ioctl.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c
index 91c3017..a4e520b 100644
--- a/drivers/tty/vt/vt_ioctl.c
+++ b/drivers/tty/vt/vt_ioctl.c
@@ -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();
}
--
1.8.3.1
