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Date:   Mon, 21 Feb 2022 11:34:15 -0600
From:   "Gustavo A. R. Silva" <gustavoars@kernel.org>
To:     "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>
Cc:     linux-usb@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        linux-hardening@vger.kernel.org
Subject: [PATCH][next] usbnet: gl620a: Replace one-element array with
 flexible-array member
Message-ID: <20220221173415.GA1149599@embeddedor>
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There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members”[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].

This helps with the ongoing efforts to globally enable -Warray-bounds
and get us closer to being able to tighten the FORTIFY_SOURCE routines
on memcpy().

This issue was found with the help of Coccinelle and audited and fixed,
manually.

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/79
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/net/usb/gl620a.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/usb/gl620a.c b/drivers/net/usb/gl620a.c
index 13a9a83b8538..46af78caf457 100644
--- a/drivers/net/usb/gl620a.c
+++ b/drivers/net/usb/gl620a.c
@@ -56,7 +56,7 @@
 
 struct gl_packet {
 	__le32		packet_length;
-	char		packet_data [1];
+	char		packet_data[];
 };
 
 struct gl_header {
-- 
2.27.0