linux-kernel - Re: [PATCH] nvmet-fc: use zero-sized array and struct

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]

Date:   Sat, 23 Feb 2019 12:05:50 -0800
From:   Joe Perches <joe@...ches.com>
To:     "Gustavo A. R. Silva" <gustavo@...eddedor.com>,
        James Smart <james.smart@...adcom.com>,
        Christoph Hellwig <hch@....de>,
        Sagi Grimberg <sagi@...mberg.me>
Cc:     linux-nvme@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] nvmet-fc: use zero-sized array and struct_size() in
 kzalloc()

On Sat, 2019-02-23 at 12:51 -0600, Gustavo A. R. Silva wrote:
> Update the code to use a zero-sized array instead of a pointer in
> structure nvmet_fc_tgt_queue and use struct_size() in kzalloc().
[]
> This code was detected with the help of Coccinelle.

Really?
Impressive script that found this one.

> diff --git a/drivers/nvme/target/fc.c b/drivers/nvme/target/fc.c
[]
> @@ -128,12 +128,12 @@ struct nvmet_fc_tgt_queue {
>  	struct nvmet_cq			nvme_cq;
>  	struct nvmet_sq			nvme_sq;
>  	struct nvmet_fc_tgt_assoc	*assoc;
> -	struct nvmet_fc_fcp_iod		*fod;		/* array of fcp_iods */
>  	struct list_head		fod_list;
>  	struct list_head		pending_cmd_list;
>  	struct list_head		avail_defer_list;
>  	struct workqueue_struct		*work_q;
>  	struct kref			ref;
> +	struct nvmet_fc_fcp_iod		fod[];		/* array of fcp_iods */
>  } __aligned(sizeof(unsigned long long));

Moving a pointer from the middle of a struct to
the end seems unusual for coccinelle.