From patchwork Mon Oct 9 21:46:18 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: 13414568 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 DA11D42BF5; Mon, 9 Oct 2023 21:46:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DbzY3biD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 416FBC433C8; Mon, 9 Oct 2023 21:46:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1696887983; bh=hOV1TPaxRK6lKBeU8FkupnPDNPfBklnFK2iqPujS67E=; h=Date:From:To:Cc:Subject:From; b=DbzY3biDgO4mfCIA4qPzupLl+uX9GQuhb11X3aVuywb+Bl5IiANsNQ87Dq6LSmK2G N+NCZxZ6Io0Elk4NgT8Tu4MX/Wbc/Zlyh+3yaAk2picUd7NwkzG2epTTBf92SeO7Zn H+iQ5RERpBZ9vTb3eOW5ELre2i0mPtM7mA2AkKXShWbogN5G9ftpllRSnRVZDjiX+u Z6gHzuzsir9EofnMs4F0iGxxpYt+rRTCLF4k2fA0rHNG8r99DhPaFICqWsqKebAfxR EltoEEpdN8DY7vzaPZL+x8Im429T6LSYjnYmhGiioMo6fjMsYsbjcQft4CvhkJ7dap wytsDX0E0V9tg== Date: Mon, 9 Oct 2023 15:46:18 -0600 From: "Gustavo A. R. Silva" To: Chandrashekar Devegowda , Intel Corporation , Chiranjeevi Rapolu , Liu Haijun , M Chetan Kumar , Ricardo Martinez , Loic Poulain , Sergey Ryazanov , Johannes Berg , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH][next] net: wwan: t7xx: Add __counted_by for struct t7xx_fsm_event 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). 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 --- drivers/net/wwan/t7xx/t7xx_state_monitor.c | 3 ++- drivers/net/wwan/t7xx/t7xx_state_monitor.h | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/wwan/t7xx/t7xx_state_monitor.c b/drivers/net/wwan/t7xx/t7xx_state_monitor.c index 80edb8e75a6a..0bc97430211b 100644 --- a/drivers/net/wwan/t7xx/t7xx_state_monitor.c +++ b/drivers/net/wwan/t7xx/t7xx_state_monitor.c @@ -445,7 +445,8 @@ int t7xx_fsm_append_event(struct t7xx_fsm_ctl *ctl, enum t7xx_fsm_event_state ev return -EINVAL; } - event = kmalloc(sizeof(*event) + length, in_interrupt() ? GFP_ATOMIC : GFP_KERNEL); + event = kmalloc(struct_size(event, data, length), + in_interrupt() ? GFP_ATOMIC : GFP_KERNEL); if (!event) return -ENOMEM; diff --git a/drivers/net/wwan/t7xx/t7xx_state_monitor.h b/drivers/net/wwan/t7xx/t7xx_state_monitor.h index b6e76f3903c8..b0b3662ae6d7 100644 --- a/drivers/net/wwan/t7xx/t7xx_state_monitor.h +++ b/drivers/net/wwan/t7xx/t7xx_state_monitor.h @@ -102,7 +102,7 @@ struct t7xx_fsm_event { struct list_head entry; enum t7xx_fsm_event_state event_id; unsigned int length; - unsigned char data[]; + unsigned char data[] __counted_by(length); }; struct t7xx_fsm_command {