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Subject: Re: [PATCH] vc04_services: vchiq_arm: fix a NULL pointer dereference
To:     Kangjie Lu <kjlu@umn.edu>
Cc:     devel@driverdev.osuosl.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Phil Elwell <phil@raspberrypi.org>,
        linux-kernel@vger.kernel.org,
        =?UTF-8?Q?Tobias_B=c3=bcttner?= <tobias.buettner@fau.de>,
        Eric Anholt <eric@anholt.net>,
        Luis Chamberlain <mcgrof@kernel.org>,
        linux-rpi-kernel@lists.infradead.org, pakki001@umn.edu,
        Dominic Braun <inf.braun@fau.de>,
        Nicolas Saenz Julienne <nsaenzjulienne@suse.de>,
        linux-arm-kernel@lists.infradead.org
References: <20190324224331.1163-1-kjlu@umn.edu>
From:   Stefan Wahren <stefan.wahren@i2se.com>
Message-ID: <61d81106-ec5a-c5a1-4757-85cdc7944f41@i2se.com>
Date:   Mon, 25 Mar 2019 10:15:50 +0100
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Hi Kangjie,

Am 24.03.19 um 23:43 schrieb Kangjie Lu:
> When kzalloc fails, "platform_state->inited = 1" is a NULL pointer
> dereference. The fix returns VCHIQ_ERROR in case it failed to
> avoid NULL pointer dereference.
>
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
please add a proper fixes tag.
> ---
>  .../staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c  | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
> index dd4898861b83..0f12fe617575 100644
> --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
> +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
> @@ -209,6 +209,8 @@ vchiq_platform_init_state(struct vchiq_state *state)
>  	struct vchiq_2835_state *platform_state;
>  
>  	state->platform_state = kzalloc(sizeof(*platform_state), GFP_KERNEL);
> +	if (!state->platform_state)
> +		return VCHIQ_ERROR;

this change is good, but vchiq_init_state doesn't bail out immediately
in case vchiq_platform_init_state fails.

Could you please fix that, too?

Thanks Stefan

>  	platform_state = (struct vchiq_2835_state *)state->platform_state;
>  
>  	platform_state->inited = 1;