From: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Date: Thu, 25 Mar 2021 20:11:17 -0500
Subject: [PATCH] cifs: cifspdu.h: Replace one-element array with
 flexible-array member
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Git-commit: 9f4c6eed26a2b7e3ce20c54e691357e0e69cc8c2
Patch-mainline: v5.13-rc1
References: bsc#1192606

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].

Also, this helps with the ongoing efforts to enable -Warray-bounds by
fixing the following warning:

  CC [M]  fs/cifs/cifssmb.o
fs/cifs/cifssmb.c: In function ‘CIFSFindNext’:
fs/cifs/cifssmb.c:4636:23: warning: array subscript 1 is above array bounds of ‘char[1]’ [-Warray-bounds]
 4636 |   pSMB->ResumeFileName[name_len+1] = 0;
      |   ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/109
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
---
 fs/cifs/cifspdu.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/cifs/cifspdu.h b/fs/cifs/cifspdu.h
index 9adc74bd9f8f..b53a87db282f 100644
--- a/fs/cifs/cifspdu.h
+++ b/fs/cifs/cifspdu.h
@@ -1903,7 +1903,7 @@ typedef struct smb_com_transaction2_fnext_req {
 	__le16 InformationLevel;
 	__u32 ResumeKey;
 	__le16 SearchFlags;
-	char ResumeFileName[1];
+	char ResumeFileName[];
 } __attribute__((packed)) TRANSACTION2_FNEXT_REQ;
 
 typedef struct smb_com_transaction2_fnext_rsp {
-- 
2.33.1