Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <f0cc1d69-71a2-e50d-07ea-b17ab26d6cf4@igalia.com>
Date:   Wed, 2 Aug 2023 12:46:49 -0300
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.11.0
Subject: Re: [PATCH 1/1] pstore/ram: Check member of buffers during the
 initialization phase of the pstore
Content-Language: en-US
To:     Yunlong Xing <yunlong.xing@unisoc.com>, keescook@chromium.org,
        tony.luck@intel.com, joel@joelfernandes.org, enlin.mu@unisoc.com
Cc:     linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org,
        enlinmu@gmail.com, yunlong.xing23@gmail.com
References: <20230801060432.1307717-1-yunlong.xing@unisoc.com>
From:   "Guilherme G. Piccoli" <gpiccoli@igalia.com>
In-Reply-To: <20230801060432.1307717-1-yunlong.xing@unisoc.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 01/08/2023 03:04, Yunlong Xing wrote:
> [...]

> diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
> index 85aaf0fc6d7d..eb6df190d752 100644
> --- a/fs/pstore/ram_core.c
> +++ b/fs/pstore/ram_core.c
> @@ -519,7 +519,7 @@ static int persistent_ram_post_init(struct persistent_ram_zone *prz, u32 sig,
>  	sig ^= PERSISTENT_RAM_SIG;
>  
>  	if (prz->buffer->sig == sig) {
> -		if (buffer_size(prz) == 0) {
> +		if (buffer_size(prz) == 0 && buffer_start(prz) == 0) {
>  			pr_debug("found existing empty buffer\n");

Thanks for the patch! I'd also adjust the above print statement to
reflect the different paths (empty buffers vs illegal one) and maybe
bump it to pr_info, or even pr_warn(_once?).

What do you all think, makes sense or could we pollute dmesg too much?
Cheers!