Re: [Tee-dev] [PATCH] tee: shm: fix use-after-free via temporarily dropped reference

[Volodymyr Babchuk]

Hi Jens,

On 7 May 2018 at 12:58, Jens Wiklander <jens.wiklander@xxxxxxxxxx> wrote:
> From: Jann Horn <jannh@xxxxxxxxxx>
>
> Bump the file's refcount before moving the reference into the fd table,
> not afterwards. The old code could drop the file's refcount to zero for a
> short moment before calling get_file() via get_dma_buf().
>
> This code can only be triggered on ARM systems that use Linaro's OP-TEE.
>
> Fixes: 967c9cca2cc5 ("tee: generic TEE subsystem")
> Signed-off-by: Jann Horn <jannh@xxxxxxxxxx>
> Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
Reviewed-by: Volodymyr Babchuk <vlad.babchuk@xxxxxxxxx>

-- 
WBR Volodymyr Babchuk aka lorc [+380976646013]
mailto: vlad.babchuk@xxxxxxxxx