linux-kernel - Re: [PATCH][next] ath: Replace zero-length array with flexible-array member

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] [day] [month] [year] [list]

Date:   Mon, 23 Mar 2020 17:38:48 +0000 (UTC)
From:   Kalle Valo <kvalo@...eaurora.org>
To:     "Gustavo A. R. Silva" <gustavo@...eddedor.com>
Cc:     "David S. Miller" <davem@...emloft.net>,
        Christian Lamparter <chunkeey@...glemail.com>,
        Maxime Coquelin <mcoquelin.stm32@...il.com>,
        Alexandre Torgue <alexandre.torgue@...com>,
        Maya Erez <merez@...eaurora.org>, ath10k@...ts.infradead.org,
        linux-wireless@...r.kernel.org, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, ath11k@...ts.infradead.org,
        wcn36xx@...ts.infradead.org,
        linux-stm32@...md-mailman.stormreply.com,
        linux-arm-kernel@...ts.infradead.org, wil6210@....qualcomm.com,
        "Gustavo A. R. Silva" <gustavo@...eddedor.com>
Subject: Re: [PATCH][next] ath: Replace zero-length array with flexible-array
 member

"Gustavo A. R. Silva" <gustavo@...eddedor.com> wrote:

> The current codebase makes use of the zero-length array language
> extension to the C90 standard, but the preferred mechanism to declare
> variable-length types such as these ones is a flexible array member[1][2],
> introduced in C99:
> 
> struct foo {
>         int stuff;
>         struct boo array[];
> };
> 
> By making use of the mechanism above, we will get a compiler warning
> in case the flexible array does not occur last in the structure, which
> will help us prevent some kind of undefined behavior bugs from being
> inadvertently introduced[3] to the codebase from now on.
> 
> Also, notice that, dynamic memory allocations won't be affected by
> this change:
> 
> "Flexible array members have incomplete type, and so the sizeof operator
> may not be applied. As a quirk of the original implementation of
> zero-length arrays, sizeof evaluates to zero."[1]
> 
> This issue was detected with the help of Coccinelle.
> 
> [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
> [2] https://github.com/KSPP/linux/issues/21
> [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@...eddedor.com>

Fails to apply, please rebase on top of my ath.git master branch.

error: patch failed: drivers/net/wireless/ath/ath10k/core.h:1223
error: drivers/net/wireless/ath/ath10k/core.h: patch does not apply
error: patch failed: drivers/net/wireless/ath/ath11k/debug.h:65
error: drivers/net/wireless/ath/ath11k/debug.h: patch does not apply
error: patch failed: drivers/net/wireless/ath/ath11k/rx_desc.h:1206
error: drivers/net/wireless/ath/ath11k/rx_desc.h: patch does not apply
stg import: Diff does not apply cleanly

Patch set to Changes Requested.

-- 
https://patchwork.kernel.org/patch/11401227/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches