Commit 241fe395 authored by Kees Cook's avatar Kees Cook
Browse files

bnxt_en: Use struct_group_attr() for memcpy() region 



In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memcpy(), memmove(), and memset(), avoid
intentionally writing across neighboring fields.

Use struct_group() around members queue_id, min_bw, max_bw, tsa, pri_lvl,
and bw_weight so they can be referenced together. This will allow memcpy()
and sizeof() to more easily reason about sizes, improve readability,
and avoid future warnings about writing beyond the end of queue_id.

"pahole" shows no size nor member offset changes to struct bnxt_cos2bw_cfg.
"objdump -d" shows no meaningful object code changes (i.e. only source
line number induced differences and optimizations).

Cc: Michael Chan <michael.chan@broadcom.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Reviewed-by: default avatarMichael Chan <michael.chan@broadcom.com>
Link: https://lore.kernel.org/lkml/CACKFLinDc6Y+P8eZ=450yA1nMC7swTURLtcdyiNR=9J6dfFyBg@mail.gmail.com


Reviewed-by: default avatarGustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/lkml/20210728044517.GE35706@embeddedor
parent 301e68dd

drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.c

+2 −2
Original line number Diff line number Diff line
@@ -159,10 +159,10 @@ static int bnxt_hwrm_queue_cos2bw_qcfg(struct bnxt *bp, struct ieee_ets *ets) 
	}



	data = &resp->queue_id0 + offsetof(struct bnxt_cos2bw_cfg, queue_id);

	for (i = 0; i < bp->max_tc; i++, data += sizeof(cos2bw) - 4) {

	for (i = 0; i < bp->max_tc; i++, data += sizeof(cos2bw.cfg)) {

		int tc;



		memcpy(&cos2bw.queue_id, data, sizeof(cos2bw) - 4);

		memcpy(&cos2bw.cfg, data, sizeof(cos2bw.cfg));

		if (i == 0)

			cos2bw.queue_id = resp->queue_id0;

drivers/net/ethernet/broadcom/bnxt/bnxt_dcb.h

+8 −6
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ struct bnxt_dcb { 


struct bnxt_cos2bw_cfg {

	u8			pad[3];

	struct_group_attr(cfg, __packed,

		u8		queue_id;

		__le32		min_bw;

		__le32		max_bw;
@@ -30,6 +31,7 @@ struct bnxt_cos2bw_cfg { 
		u8		tsa;

		u8		pri_lvl;

		u8		bw_weight;

	);

	u8			unused;

};