linux-kernel - Re: [PATCH] serial: st-asc: don't get/put GPIOs in atomic context

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CACRpkdbULXPDDtXcBDrme54yYxKOSaAzwZPyT_H+gfyUPNXRMw@mail.gmail.com>
Date: Wed, 14 Feb 2024 17:16:28 +0100
From: Linus Walleij <linus.walleij@...aro.org>
To: Bartosz Golaszewski <brgl@...ev.pl>
Cc: Patrice Chotard <patrice.chotard@...s.st.com>, 
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>, Jiri Slaby <jirislaby@...nel.org>, 
	Dan Carpenter <dan.carpenter@...aro.org>, linux-kernel@...r.kernel.org, 
	linux-serial@...r.kernel.org, 
	Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Subject: Re: [PATCH] serial: st-asc: don't get/put GPIOs in atomic context

On Wed, Feb 14, 2024 at 10:24 AM Bartosz Golaszewski <brgl@...ev.pl> wrote:

> From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
>
> Since commit 1f2bcb8c8ccd ("gpio: protect the descriptor label with
> SRCU") gpiod_set_consumer_name() calls synchronize_srcu() which led to
> a "sleeping in atomic context" smatch warning.
>
> This function (along with gpiod_get/put() and all other GPIO APIs apart
> from gpiod_get/set_value() and gpiod_direction_input/output()) should
> have never been called with a spinlock taken. We're only fixing this now
> as GPIOLIB has been rebuilt to use SRCU for access serialization which
> uncovered this problem.
>
> Move the calls to gpiod_get/put() outside the spinlock critical section.
>
> Reported-by: Dan Carpenter <dan.carpenter@...aro.org>
> Closes: https://lore.kernel.org/linux-gpio/deee1438-efc1-47c4-8d80-0ab2cf01d60a@moroto.mountain/
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>

Good find!
Reviewed-by: Linus Walleij <linus.walleij@...aro.org>

Yours,
Linus Walleij