[PATCH] scsi: uapi: Replace 0-length array with flexible array

[Kees Cook]

Zero-length arrays are deprecated[1]. Replace struct
fc_bsg_host_vendor_reply's "vendor_rsp" 0-length array with a flexible
array. Detected with GCC 13, using -fstrict-flex-arrays=3:

drivers/scsi/qla2xxx/qla_isr.c: In function 'qla25xx_process_bidir_status_iocb.isra':
drivers/scsi/qla2xxx/qla_isr.c:3117:54: warning: array subscript 0 is outside array bounds of '__u32[0]' {aka 'unsigned int[]'} [-Warray-bounds=]
 3117 |         bsg_reply->reply_data.vendor_reply.vendor_rsp[0] = rval;
      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~
In file included from drivers/scsi/qla2xxx/qla_def.h:34,
                 from drivers/scsi/qla2xxx/qla_isr.c:6:
include/uapi/scsi/scsi_bsg_fc.h:219:15: note: while referencing 'vendor_rsp'
  219 |         __u32 vendor_rsp[0];
      |               ^~~~~~~~~~

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays

Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 include/uapi/scsi/scsi_bsg_fc.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/uapi/scsi/scsi_bsg_fc.h b/include/uapi/scsi/scsi_bsg_fc.h
index 7f5930801f72..5e46cf1054af 100644
--- a/include/uapi/scsi/scsi_bsg_fc.h
+++ b/include/uapi/scsi/scsi_bsg_fc.h
@@ -216,7 +216,7 @@ struct fc_bsg_host_vendor {
  */
 struct fc_bsg_host_vendor_reply {
 	/* start of vendor response area */
-	__u32 vendor_rsp[0];
+	__DECLARE_FLEX_ARRAY(__u32, vendor_rsp);
 };
 
 
-- 
2.34.1