Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for
array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).
Use struct_size() and flex_array_size() helpers to calculate proper sizes
for allocation and memcpy().
Don't change logic at all, and result is identical as before.
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx>
---
drivers/net/wireless/realtek/rtw89/coex.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)
diff --git a/drivers/net/wireless/realtek/rtw89/coex.c b/drivers/net/wireless/realtek/rtw89/coex.c
index 4ba8b3df70ae..9f9da122f3f8 100644
--- a/drivers/net/wireless/realtek/rtw89/coex.c
+++ b/drivers/net/wireless/realtek/rtw89/coex.c
@@ -237,7 +237,7 @@ struct rtw89_btc_btf_set_report {
struct rtw89_btc_btf_set_slot_table {
u8 fver;
u8 tbl_num;
- u8 buf[];
+ struct rtw89_btc_fbtc_slot tbls[] __counted_by(tbl_num);
} __packed;
struct rtw89_btc_btf_set_mon_reg {
@@ -1821,19 +1821,17 @@ static void rtw89_btc_fw_en_rpt(struct rtw89_dev *rtwdev,
static void rtw89_btc_fw_set_slots(struct rtw89_dev *rtwdev, u8 num,
struct rtw89_btc_fbtc_slot *s)
{
- struct rtw89_btc_btf_set_slot_table *tbl = NULL;
- u8 *ptr = NULL;
- u16 n = 0;
+ struct rtw89_btc_btf_set_slot_table *tbl;
+ u16 n;
- n = sizeof(*s) * num + sizeof(*tbl);
+ n = struct_size(tbl, tbls, num);
tbl = kmalloc(n, GFP_KERNEL);
if (!tbl)
return;
tbl->fver = BTF_SET_SLOT_TABLE_VER;
tbl->tbl_num = num;
- ptr = &tbl->buf[0];
- memcpy(ptr, s, num * sizeof(*s));
+ memcpy(tbl->tbls, s, flex_array_size(tbl, tbls, num));
_send_fw_cmd(rtwdev, BTFC_SET, SET_SLOT_TABLE, tbl, n);
--
2.25.1
