From patchwork Mon Oct 9 21:42:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 13414566 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CD8A141E4F for ; Mon, 9 Oct 2023 21:42:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LhxZG3fG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D458AC433C7; Mon, 9 Oct 2023 21:42:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1696887728; bh=kq7cApyaT7hqQOO78PhiQUyzEI02824CzKv278QATpY=; h=Date:From:To:Cc:Subject:From; b=LhxZG3fGzzNxCc8RPo3e5Apt/vaJKOUso5HbDl0esgi/4BcjGd46MWi6EjUemPJM0 eC3Yo/QQtFvvtIshkn3s5CzSQveQ1RLlh+VJpdtrnMhz1+dhL2I0IKkaueyS2krcvZ UtdFf9SjO5lWp5TdS5Gorhp/lJjHWhFmHn8fGkxrpYnMk2s6hLkgG2Hn58bh3ZSN6v k1pAj8vT1qSI1jn2cXNdhOLb7XBnKUAgVf1E9D7N63CgW/1h+ISrufFpCghZkCbfDZ Le1a/d7Fa1uvsVA4+TXZEKboWAEBshbN91oiFmrkUD3myeRkg5ulbbNJ/pW/q/EJxH 5FBDRwAxf+zig== Date: Mon, 9 Oct 2023 15:42:04 -0600 From: "Gustavo A. R. Silva" To: Arend van Spriel , Franky Lin , Hante Meuleman , Kalle Valo Cc: linux-wireless@vger.kernel.org, brcm80211-dev-list.pdl@broadcom.com, SHA-cyfmac-dev-list@infineon.com, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH][next] wifi: brcmfmac: fweh: Add __counted_by for struct brcmf_fweh_queue_item and use struct_size() Message-ID: Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline 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). Also, relocate `event->datalen = datalen;` to before calling `memcpy(event->data, data, datalen);`, so that the __counted_by annotation has effect, and flex-array member `data` can be properly bounds-checked at run-time. While there, use struct_size() helper, instead of the open-coded version, to calculate the size for the allocation of the whole flexible structure, including of course, the flexible-array member. This code was found with the help of Coccinelle, and audited and fixed manually. Signed-off-by: Gustavo A. R. Silva Reviewed-by: Kees Cook Acked-by: Arend van Spriel --- drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c index dac7eb77799b..68960ae98987 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c @@ -33,7 +33,7 @@ struct brcmf_fweh_queue_item { u8 ifaddr[ETH_ALEN]; struct brcmf_event_msg_be emsg; u32 datalen; - u8 data[]; + u8 data[] __counted_by(datalen); }; /* @@ -418,17 +418,17 @@ void brcmf_fweh_process_event(struct brcmf_pub *drvr, datalen + sizeof(*event_packet) > packet_len) return; - event = kzalloc(sizeof(*event) + datalen, gfp); + event = kzalloc(struct_size(event, data, datalen), gfp); if (!event) return; + event->datalen = datalen; event->code = code; event->ifidx = event_packet->msg.ifidx; /* use memcpy to get aligned event message */ memcpy(&event->emsg, &event_packet->msg, sizeof(event->emsg)); memcpy(event->data, data, datalen); - event->datalen = datalen; memcpy(event->ifaddr, event_packet->eth.h_dest, ETH_ALEN); brcmf_fweh_queue_event(fweh, event);