Re: [PATCH] wifi: brcmfmac: cyw: Fix __counted_by to be LE variant

[Gustavo A. R. Silva]

On 21/07/25 12:18, Kees Cook wrote:

In brcmf_cyw_mgmt_tx() the "len" counter of the struct
brcmf_mf_params_le::data flexible array is stored as little-endian via
cpu_to_le16() so the __counted_by_le() variant must be used:

        struct brcmf_mf_params_le *mf_params;
        ...
        mf_params_len = offsetof(struct brcmf_mf_params_le, data) +
                        (len - DOT11_MGMT_HDR_LEN);
        mf_params = kzalloc(mf_params_len, GFP_KERNEL);
        ...
         mf_params->len = cpu_to_le16(len - DOT11_MGMT_HDR_LEN);

Fixes: 66f909308a7c ("wifi: brcmfmac: cyw: support external SAE authentication in 
station mode")
Signed-off-by: Kees Cook <k...@kernel.org>

Reviewed-by: Gustavo A. R. Silva <gustavo...@kernel.org>

Thanks!
-Gustavo

---
Cc: Johannes Berg <johannes.b...@intel.com>
Cc: Chung-Hsien Hsu <chung-hsien....@infineon.com>
Cc: Chi-hsien Lin <chi-hsien....@infineon.com>
Cc: James Prestwood <prest...@gmail.com>
Cc: Arend van Spriel <arend.vanspr...@broadcom.com>
Cc: "Gustavo A. R. Silva" <gustavo...@kernel.org>
Cc: Ting-Ying Li <tingying...@cypress.com>
Cc: <linux-wirel...@vger.kernel.org>
Cc: <brcm80...@lists.linux.dev>
Cc: <brcm80211-dev-list....@broadcom.com>
Cc: <linux-hardening@vger.kernel.org>
---
  .../net/wireless/broadcom/brcm80211/brcmfmac/cyw/fwil_types.h   | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cyw/fwil_types.h 
b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cyw/fwil_types.h
index 08c69142495a..669564382e32 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cyw/fwil_types.h
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cyw/fwil_types.h
@@ -80,7 +80,7 @@ struct brcmf_mf_params_le {
        u8 da[ETH_ALEN];
        u8 bssid[ETH_ALEN];
        __le32 packet_id;
-       u8 data[] __counted_by(len);
+       u8 data[] __counted_by_le(len);
  };

#endif /* CYW_FWIL_TYPES_H_ */