tty: limit terminal size to 4M chars

Size of kmalloc() in vc_do_resize() is controlled by user.
Too large kmalloc() size triggers WARNING message on console.
Put a reasonable upper bound on terminal size to prevent WARNINGs.

Signed-off-by: Dmitry Vyukov <[email protected]>
CC: David Rientjes <[email protected]>
Cc: One Thousand Gnomes <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Peter Hurley <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: stable <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
This commit is contained in:
Dmitry Vyukov 2016-10-14 15:18:28 +02:00 • committed by Greg Kroah-Hartman
commit 32b2921e6a

View file

@ -870,6 +870,8 @@ static int vc_do_resize(struct tty_struct *tty, struct vc_data *vc,
if (new_cols == vc->vc_cols && new_rows == vc->vc_rows)
return 0;
if (new_screen_size > (4 << 20))
return -EINVAL;
newscreen = kmalloc(new_screen_size, GFP_USER);
if (!newscreen)
return -ENOMEM;