Re: [PATCH] pinctrl: devicetree: fix null pointer dereferencing in pinctrl_dt_to_map

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

On Thu, Nov 10, 2022 at 9:22 AM Zeng Heng <zengheng4@xxxxxxxxxx> wrote:

> Here is the BUG report by KASAN about null pointer dereference:
>
> BUG: KASAN: null-ptr-deref in strcmp+0x2e/0x50
> Read of size 1 at addr 0000000000000000 by task python3/2640
> Call Trace:
>  strcmp
>  __of_find_property
>  of_find_property
>  pinctrl_dt_to_map
>
> kasprintf() would return NULL pointer when kmalloc() fail to allocate.
> So directly return ENOMEM, if kasprintf() return NULL pointer.
>
> Fixes: 57291ce295c0 ("pinctrl: core device tree mapping table parsing support")
> Signed-off-by: Zeng Heng <zengheng4@xxxxxxxxxx>

Patch applied for fixes.

Interesting that you managed to locate this using *kasan* of all
things, it kind of requires that you manage to run out of memory
exactly at this time...

Yours,
Linus Walleij