Re: [SRU][F:linux-bluefield][PATCH v2 1/2] gpio: Restrict usage of GPIO chip irq members before initialization

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Feb 17, 2023 at 09:07:43AM -0500, Asmaa Mnebhi wrote:
> BugLink: https://bugs.launchpad.net/bugs/2007581
> 
> GPIO chip irq members are exposed before they could be completely
> initialized and this leads to race conditions.
> 
> One such issue was observed for the gc->irq.domain variable which
> was accessed through the I2C interface in gpiochip_to_irq() before
> it could be initialized by gpiochip_add_irqchip(). This resulted in
> Kernel NULL pointer dereference.
> 
> Following are the logs for reference :-
> 
> kernel: Call Trace:
> kernel:  gpiod_to_irq+0x53/0x70
> kernel:  acpi_dev_gpio_irq_get_by+0x113/0x1f0
> kernel:  i2c_acpi_get_irq+0xc0/0xd0
> kernel:  i2c_device_probe+0x28a/0x2a0
> kernel:  really_probe+0xf2/0x460
> kernel: RIP: 0010:gpiochip_to_irq+0x47/0xc0
> 
> To avoid such scenarios, restrict usage of GPIO chip irq members before
> they are completely initialized.
> 
> Signed-off-by: Shreeya Patel <shreeya.patel@collabora.com>
> Cc: stable@vger.kernel.org
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
> (backported from commit 5467801f1fcbdc46bc7298a84dbf3ca1ff2a7320)
> Signed-off-by: Asmaa Mnebhi <asmaa@nvidia.com>


<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>