[PATCH 1/1] fru: ops: avoid out of bounds access

[Heinrich Schuchardt]

Building xilinx_zynq_virt_defconfig fails on origin/next as reported by
GCC 10.2 (as provided by Debian Bullseye):

  CC      board/xilinx/common/fru_ops.o
board/xilinx/common/fru_ops.c: In function ‘fru_capture’:
board/xilinx/common/fru_ops.c:173:8:
error: array subscript 284 is outside array bounds of
‘struct fru_table[1]’ [-Werror=array-bounds]
  173 |  limit = data + sizeof(struct fru_board_data);
      |  ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
board/xilinx/common/fru_ops.c:17:18: note: while referencing ‘fru_data’
   17 | struct fru_table fru_data __section(.data);
      |                  ^~~~~~~~

When using sizeof(struct fru_board_data) to find the end of the structure
you should add it to the start of the structure.

Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
---
 board/xilinx/common/fru_ops.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/board/xilinx/common/fru_ops.c b/board/xilinx/common/fru_ops.c
index b4cd3d4998..44f0913f2e 100644
--- a/board/xilinx/common/fru_ops.c
+++ b/board/xilinx/common/fru_ops.c
@@ -170,7 +170,7 @@ static int fru_parse_board(unsigned long addr)
 	data = (u8 *)&fru_data.brd.manufacturer_type_len;

 	/* Record max structure limit not to write data over allocated space */
-	limit = data + sizeof(struct fru_board_data);
+	limit = (u8 *)&fru_data.brd + sizeof(struct fru_board_data);

 	for (i = 0; ; i++, data += FRU_BOARD_MAX_LEN) {
 		len = fru_check_type_len(*(u8 *)addr, fru_data.brd.lang_code,
--
2.29.2