From: Zheng Hacker <hackerzheng666@gmail.com>
To: xmzyshypnc <1002992920@qq.com>
Cc: alex000young@gmail.com, security@kernel.org,
dri-devel@lists.freedesktop.org, tvrtko.ursulin@linux.intel.com,
airlied@linux.ie, Greg KH <gregkh@linuxfoundation.org>,
intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org,
rodrigo.vivi@intel.com, intel-gvt-dev@lists.freedesktop.org,
zhi.a.wang@intel.com
Subject: Re: [PATCH] drm/i915/gvt: fix double-free bug in split_2MB_gtt_entry.
Date: Mon, 5 Sep 2022 15:35:05 +0800 [thread overview]
Message-ID: <CAJedcCw1eJqjSK+yR7eQMDheNtH3Mjm+viwt00xAhnmrfpq2pw@mail.gmail.com> (raw)
In-Reply-To: <CAJedcCxVW++iH49UFZp9ruUuTcNubWCH6Wsqe11K4COB3E8msg@mail.gmail.com>
Hi everyone,
Now the letter is really plain-text now :)
Thanks Greg
Regards,
Zheng Wang
Zheng Hacker <hackerzheng666@gmail.com> 于2022年9月5日周一 12:47写道:
>
> Hello everyone,
>
> I'm Zheng Wang. I found a potential double-free bug in drivers/gpu/drm/i915/gvt/gtt.c. I haven't been replied for a long time. So I decided to send it to more relavent supporters and developers to help to solve the problem.
>
> Best regards,
> Zheng Wang.
>
> xmzyshypnc <1002992920@qq.com> 于2022年9月4日周日 20:32写道:
>>
>> There is a double-free security bug in split_2MB_gtt_entry.
>>
>> Here is a calling chain : ppgtt_populate_spt->ppgtt_populate_shadow_entry->split_2MB_gtt_entry. If intel_gvt_dma_map_guest_page failed, it will call ppgtt_invalidate_spt, which will finally call ppgtt_free_spt and kfree(spt). But the caller does not notice that, and it will call ppgtt_free_spt again in error path.
>>
>> Fix this by returning the result of ppgtt_invalidate_spt to split_2MB_gtt_entry.
>>
>> Signed-off-by: Zheng Wang <1002992920@qq.com>
>> ---
>> drivers/gpu/drm/i915/gvt/gtt.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
>> index ce0eb03709c3..9f14fded8c0c 100644
>> --- a/drivers/gpu/drm/i915/gvt/gtt.c
>> +++ b/drivers/gpu/drm/i915/gvt/gtt.c
>> @@ -1215,7 +1215,7 @@ static int split_2MB_gtt_entry(struct intel_vgpu *vgpu,
>> ret = intel_gvt_dma_map_guest_page(vgpu, start_gfn + sub_index,
>> PAGE_SIZE, &dma_addr);
>> if (ret) {
>> - ppgtt_invalidate_spt(spt);
>> + ret = ppgtt_invalidate_spt(spt);
>> return ret;
>> }
>> sub_se.val64 = se->val64;
>> --
>> 2.25.1
>>
next prev parent reply other threads:[~2022-09-05 7:35 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <tencent_E1BBF05904DFB73C478DCD592740AAE0780A@qq.com>
2022-09-05 4:47 ` [PATCH] drm/i915/gvt: fix double-free bug in split_2MB_gtt_entry Zheng Hacker
2022-09-05 6:11 ` Zheng Hacker
2022-09-05 7:35 ` Zheng Hacker [this message]
2022-09-05 7:46 ` Zheng Hacker
2022-09-05 8:04 ` Greg KH
2022-09-05 8:53 ` Alex Young
2022-09-06 11:36 ` Zheng Hacker
2022-09-07 3:07 ` Zhenyu Wang
2022-09-07 6:47 ` Zheng Hacker
2022-09-08 9:09 ` Zheng Hacker
2022-09-08 9:19 ` Greg KH
2022-09-08 11:59 ` Zheng Hacker
2022-09-16 6:39 ` Zheng Hacker
2022-09-16 6:40 ` Zheng Hacker
2022-09-16 8:25 ` Greg KH
2022-09-16 15:21 ` Zheng Hacker
2022-09-16 15:54 ` Zheng Hacker
2022-09-17 9:08 ` Greg KH
2022-09-17 9:10 ` Zheng Hacker
2022-09-18 17:08 ` =?gb18030?B?s68=?=
2022-09-18 17:17 ` Zheng Hacker
2022-09-18 19:24 Zheng Wang
2022-09-19 9:30 ` Jani Nikula
2022-09-19 9:55 ` Zheng Hacker
2022-09-21 9:13 ` Zheng Hacker
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