From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
To: Tuo Li <islituo@gmail.com>,
inki.dae@samsung.com, sw0312.kim@samsung.com,
kyungmin.park@samsung.com, airlied@gmail.com, daniel@ffwll.ch,
alim.akhtar@samsung.com
Cc: dri-devel@lists.freedesktop.org,
linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org,
baijiaju1990@outlook.com, BassCheck <bass@buaa.edu.cn>
Subject: Re: [PATCH] drm/exynos: fix a possible null-pointer dereference due to data race in exynos_drm_crtc_atomic_disable()
Date: Tue, 4 Jul 2023 09:35:50 +0200 [thread overview]
Message-ID: <88edab79-5f9a-007d-f2e9-d264178fe80b@linaro.org> (raw)
In-Reply-To: <20230630021906.1035115-1-islituo@gmail.com>
On 30/06/2023 04:19, Tuo Li wrote:
> The variable crtc->state->event is often protected by the lock
> crtc->dev->event_lock when is accessed. However, it is accessed as a
> condition of an if statement in exynos_drm_crtc_atomic_disable() without
> holding the lock:
>
> if (crtc->state->event && !crtc->state->active)
>
> However, if crtc->state->event is changed to NULL by another thread right
> after the conditions of the if statement is checked to be true, a
> null-pointer dereference can occur in drm_crtc_send_vblank_event():
>
> e->pipe = pipe;
>
> To fix this possible null-pointer dereference caused by data race, the
> spin lock coverage is extended to protect the if statement as well as the
> function call to drm_crtc_send_vblank_event().
>
> Reported-by: BassCheck <bass@buaa.edu.cn>
> Signed-off-by: Tuo Li <islituo@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Best regards,
Krzysztof
next prev parent reply other threads:[~2023-07-04 7:36 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20230630022033epcas1p2a104f08061a51a240364b72eb43842d8@epcas1p2.samsung.com>
2023-06-30 2:19 ` [PATCH] drm/exynos: fix a possible null-pointer dereference due to data race in exynos_drm_crtc_atomic_disable() Tuo Li
2023-07-01 8:01 ` Krzysztof Kozlowski
[not found] ` <CADm8Ten-1yBdQFaETvS19j=_UFC4GEJqH38DU=7xPXLkOnvvzg@mail.gmail.com>
2023-07-04 7:27 ` Krzysztof Kozlowski
2023-07-04 7:35 ` Krzysztof Kozlowski [this message]
2023-07-13 0:32 ` 대인기/Tizen Platform Lab(SR)/삼성전자
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=88edab79-5f9a-007d-f2e9-d264178fe80b@linaro.org \
--to=krzysztof.kozlowski@linaro.org \
--cc=airlied@gmail.com \
--cc=alim.akhtar@samsung.com \
--cc=baijiaju1990@outlook.com \
--cc=bass@buaa.edu.cn \
--cc=daniel@ffwll.ch \
--cc=dri-devel@lists.freedesktop.org \
--cc=inki.dae@samsung.com \
--cc=islituo@gmail.com \
--cc=kyungmin.park@samsung.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-samsung-soc@vger.kernel.org \
--cc=sw0312.kim@samsung.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).