On Thu, May 23, 2019 at 08:34:52AM +0800, Gen Zhang wrote:
> In function con_insert_unipair(), when allocation for p2 and p1[n]
> fails, ENOMEM is returned, but previously allocated p1 is not freed,
> remains as leaking memory. Thus we should free p1 as well when this
> allocation fails.
>
> Signed-off-by: Gen Zhang <blackgod016...@gmail.com>
As far as I can see this is correct, as it's just restoring the prior
state before the p1 allocation.
Reviewed-by: Kees Cook <keesc...@chromium.org>
> ---
> diff --git a/drivers/tty/vt/consolemap.c b/drivers/tty/vt/consolemap.c
> index b28aa0d..79fcc96 100644
> --- a/drivers/tty/vt/consolemap.c
> +++ b/drivers/tty/vt/consolemap.c
> @@ -489,7 +489,11 @@ con_insert_unipair(struct uni_pagedir *p, u_short
> unicode, u_short fontpos)
> p2 = p1[n = (unicode >> 6) & 0x1f];
> if (!p2) {
> p2 = p1[n] = kmalloc_array(64, sizeof(u16), GFP_KERNEL);
> - if (!p2) return -ENOMEM;
> + if (!p2) {
> + kfree(p1);
> + p->uni_pgdir[n] = NULL;
> + return -ENOMEM;
> + }
> memset(p2, 0xff, 64*sizeof(u16)); /* No glyphs for the
> characters (yet) */
> }
>
> ---
--
Kees Cook
