From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793214547; b=qKPewzflAgfjZiqweMWIW4MxMiYR//0eqELaYK46jjDjUgDepv8WTEAJ4gk+/nmhwUPA LaO8dhh70btapQQ1ryl+NAg6NZ3JsyvPlA3iElO4Kr2Rr1BcWCdoIZEkns5XMeJY8n5/n 8pxMvH6Y6bLUiC3w/7wZuRE+lWpZHqpivp+HdZFVeswGiq8iqpQqINbQgh/BBc17Zsrza ULnDCDHDh4jJGG5tYpsb9sYBIWXN3lzouI867ngRYhK2a7R5nW1yFzWG8hIIhNO6Y7NfK ADHw3qDv6R9/nSfH3+pkh0OYiI9GhIOMo5ubbaMSoYPue3BMyp++r1rSvg/ADCYhPXQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793214547; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=zPW2vMw9fSiKgsIlro81csbwQtT1tCMx4mx31hsNyqM=; b=eeOWxd3P1VMpR2ZF8rY4lUcyjLtDdvZ7zePFC6zQ/RiUp+RAhs4osjYH71odFJKn207d V2h18LAEKDtB8cEh897QKgfnVF4DJwPjBVIdjvF/Nyc+BJ0wvmYaZ8SKo3cWxKvCfjsQO kDXP585F/YwA6355s+XfpoBZqvkPHV0uJ58kvszPK4gwIE0hpoQCzxnAh8hutJUXiwf8Y oWXzBfPGWhrdP0TF0vppdkByvMe+P0L30NVPNPOLuIgweb/w7RNQObSzjZ2vJdWT5I5B4 jGbtx4ly/DywSCUyQYXYwchVKcRyPwLCE0uP1t3BAWZiJYffvCXXD8lW+Ob5v8NTd7g== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=MHpmmDjX; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 00BBF60A263D; Wed, 28 Oct 2026 19:09:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=MHpmmDjX Received: by smtp.kernel.org (Postfix) with ESMTPSA id 51EA01F01825; Wed, 28 Oct 2026 19:09:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793214546; bh=zPW2vMw9fSiKgsIlro81csbwQtT1tCMx4mx31hsNyqM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=MHpmmDjXAQ0qht3xSfSdKo6wVktHLreaiwZFEOM5t6MdT9Z3YCNDL7gE5yYen+eql JTkot22Po8LbE39bvhD2exg5tCQqBJ5C3vusmsPIfL14r4pmzGWWwaNOmYn4z6KUb2 QgXodHXch6N076MF4+6Irvp9E6hdjixIqE5MHNkA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Marc Kleine-Budde , Sasha Levin Subject: [PATCH 6.1 0895/1887] can: gs_usb: gs_usb_receive_bulk_callback(): check actual_length before accessing data Date: Wed, 28 Oct 2026 17:49:51 +0100 Message-ID: <20261028170519.786450809@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170459.200466217@linuxfoundation.org> References: <20261028170459.200466217@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marc Kleine-Budde [ Upstream commit 395d988f93861101ec89d0dd9e3b876ae9392a5b ] The URB received in gs_usb_receive_bulk_callback() contains a struct gs_host_frame. The length of the data after the header depends on the gs_host_frame hf::flags and the active device features (e.g. time stamping). Introduce a new function gs_usb_get_minimum_length() and check that we have at least received the required amount of data before accessing it. Only copy the data to that skb that has actually been received. Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices") Link: https://patch.msgid.link/20251114-gs_usb-fix-usb-callbacks-v1-3-a29b42eacada@pengutronix.de [mkl: rename gs_usb_get_minimum_length() -> +gs_usb_get_minimum_rx_length()] Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin --- drivers/net/can/usb/gs_usb.c | 59 +++++++++++++++++++++++++++++++++--- 1 file changed, 54 insertions(+), 5 deletions(-) diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c index d0fe0e5e9021f..1f021366afab5 100644 --- a/drivers/net/can/usb/gs_usb.c +++ b/drivers/net/can/usb/gs_usb.c @@ -251,6 +251,11 @@ struct canfd_quirk { u8 quirk; } __packed; +/* struct gs_host_frame::echo_id == GS_HOST_FRAME_ECHO_ID_RX indicates + * a regular RX'ed CAN frame + */ +#define GS_HOST_FRAME_ECHO_ID_RX 0xffffffff + struct gs_host_frame { struct_group(header, u32 echo_id; @@ -523,6 +528,37 @@ static void gs_usb_set_timestamp(struct gs_can *dev, struct sk_buff *skb, return; } +static unsigned int +gs_usb_get_minimum_rx_length(const struct gs_can *dev, const struct gs_host_frame *hf, + unsigned int *data_length_p) +{ + unsigned int minimum_length, data_length = 0; + + if (hf->flags & GS_CAN_FLAG_FD) { + if (hf->echo_id == GS_HOST_FRAME_ECHO_ID_RX) + data_length = can_fd_dlc2len(hf->can_dlc); + + if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) + /* timestamp follows data field of max size */ + minimum_length = struct_size(hf, canfd_ts, 1); + else + minimum_length = sizeof(hf->header) + data_length; + } else { + if (hf->echo_id == GS_HOST_FRAME_ECHO_ID_RX && + !(hf->can_id & cpu_to_le32(CAN_RTR_FLAG))) + data_length = can_cc_dlc2len(hf->can_dlc); + + if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP) + /* timestamp follows data field of max size */ + minimum_length = struct_size(hf, classic_can_ts, 1); + else + minimum_length = sizeof(hf->header) + data_length; + } + + *data_length_p = data_length; + return minimum_length; +} + static void gs_usb_receive_bulk_callback(struct urb *urb) { struct gs_usb *parent = urb->context; @@ -531,7 +567,7 @@ static void gs_usb_receive_bulk_callback(struct urb *urb) int rc; struct net_device_stats *stats; struct gs_host_frame *hf = urb->transfer_buffer; - unsigned int minimum_length; + unsigned int minimum_length, data_length; struct gs_tx_context *txc; struct can_frame *cf; struct canfd_frame *cfd; @@ -574,20 +610,33 @@ static void gs_usb_receive_bulk_callback(struct urb *urb) if (!netif_running(netdev)) goto resubmit_urb; - if (hf->echo_id == -1) { /* normal rx */ + minimum_length = gs_usb_get_minimum_rx_length(dev, hf, &data_length); + if (urb->actual_length < minimum_length) { + stats->rx_errors++; + stats->rx_length_errors++; + + if (net_ratelimit()) + netdev_err(netdev, + "short read (actual_length=%u, minimum_length=%u)\n", + urb->actual_length, minimum_length); + + goto resubmit_urb; + } + + if (hf->echo_id == GS_HOST_FRAME_ECHO_ID_RX) { /* normal rx */ if (hf->flags & GS_CAN_FLAG_FD) { skb = alloc_canfd_skb(dev->netdev, &cfd); if (!skb) goto resubmit_urb; cfd->can_id = le32_to_cpu(hf->can_id); - cfd->len = can_fd_dlc2len(hf->can_dlc); + cfd->len = data_length; if (hf->flags & GS_CAN_FLAG_BRS) cfd->flags |= CANFD_BRS; if (hf->flags & GS_CAN_FLAG_ESI) cfd->flags |= CANFD_ESI; - memcpy(cfd->data, hf->canfd->data, cfd->len); + memcpy(cfd->data, hf->canfd->data, data_length); } else { skb = alloc_can_skb(dev->netdev, &cf); if (!skb) @@ -596,7 +645,7 @@ static void gs_usb_receive_bulk_callback(struct urb *urb) cf->can_id = le32_to_cpu(hf->can_id); can_frame_set_cc_len(cf, hf->can_dlc, dev->can.ctrlmode); - memcpy(cf->data, hf->classic_can->data, 8); + memcpy(cf->data, hf->classic_can->data, data_length); /* ERROR frames tell us information about the controller */ if (le32_to_cpu(hf->can_id) & CAN_ERR_FLAG) -- 2.53.0