From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4678AC433DF for ; Mon, 19 Oct 2020 19:05:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E2A0A22365 for ; Mon, 19 Oct 2020 19:05:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727681AbgJSTFd (ORCPT ); Mon, 19 Oct 2020 15:05:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56858 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730945AbgJSTFd (ORCPT ); Mon, 19 Oct 2020 15:05:33 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3077BC0613D0 for ; Mon, 19 Oct 2020 12:05:33 -0700 (PDT) Received: from heimdall.vpn.pengutronix.de ([2001:67c:670:205:1d::14] helo=blackshift.org) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1kUaTL-0005v5-FY; Mon, 19 Oct 2020 21:05:31 +0200 From: Marc Kleine-Budde To: linux-can@vger.kernel.org Cc: kernel@pengutronix.de, Marc Kleine-Budde Subject: [net-rfc 02/16] can: rx-offload: don't call kfree_skb() from IRQ context Date: Mon, 19 Oct 2020 21:05:10 +0200 Message-Id: <20201019190524.1285319-3-mkl@pengutronix.de> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201019190524.1285319-1-mkl@pengutronix.de> References: <20201019190524.1285319-1-mkl@pengutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2001:67c:670:205:1d::14 X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-can@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-can@vger.kernel.org A CAN driver, using the rx-offload infrastructure, is reading CAN frames (usually in IRQ context) from the hardware and placing it into the rx-offload queue to be delivered to the networking stack via NAPI. In case the rx-offload queue is full, trying to add more skbs results in the skbs being dropped using kfree_skb(). If done from hard-IRQ context this results in the following warning: [ 682.552693] ------------[ cut here ]------------ [ 682.557360] WARNING: CPU: 0 PID: 3057 at net/core/skbuff.c:650 skb_release_head_state+0x74/0x84 [ 682.566075] Modules linked in: can_raw can coda_vpu flexcan dw_hdmi_ahb_audio v4l2_jpeg imx_vdoa can_dev [ 682.575597] CPU: 0 PID: 3057 Comm: cansend Tainted: G W 5.7.0+ #18 [ 682.583098] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) [ 682.589657] [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [ 682.597423] [] (show_stack) from [] (dump_stack+0xe0/0x114) [ 682.604759] [] (dump_stack) from [] (__warn+0xc0/0x10c) [ 682.611742] [] (__warn) from [] (warn_slowpath_fmt+0x5c/0xc0) [ 682.619248] [] (warn_slowpath_fmt) from [] (skb_release_head_state+0x74/0x84) [ 682.628143] [] (skb_release_head_state) from [] (skb_release_all+0xc/0x24) [ 682.636774] [] (skb_release_all) from [] (kfree_skb+0x74/0x1c8) [ 682.644479] [] (kfree_skb) from [] (can_rx_offload_queue_sorted+0xe0/0xe8 [can_dev]) [ 682.654051] [] (can_rx_offload_queue_sorted [can_dev]) from [] (can_rx_offload_get_echo_skb+0x48/0x94 [can_dev]) [ 682.666007] [] (can_rx_offload_get_echo_skb [can_dev]) from [] (flexcan_irq+0x194/0x5dc [flexcan]) [ 682.676734] [] (flexcan_irq [flexcan]) from [] (__handle_irq_event_percpu+0x4c/0x3ec) [ 682.686322] [] (__handle_irq_event_percpu) from [] (handle_irq_event_percpu+0x2c/0x88) [ 682.695993] [] (handle_irq_event_percpu) from [] (handle_irq_event+0x38/0x5c) [ 682.704887] [] (handle_irq_event) from [] (handle_fasteoi_irq+0xc8/0x180) [ 682.713432] [] (handle_fasteoi_irq) from [] (generic_handle_irq+0x30/0x44) [ 682.722063] [] (generic_handle_irq) from [] (__handle_domain_irq+0x64/0xdc) [ 682.730783] [] (__handle_domain_irq) from [] (gic_handle_irq+0x48/0x9c) [ 682.739158] [] (gic_handle_irq) from [] (__irq_svc+0x70/0x98) [ 682.746656] Exception stack(0xe80e9dd8 to 0xe80e9e20) [ 682.751725] 9dc0: 00000001 e80e8000 [ 682.759922] 9de0: e820cf80 00000000 ffffe000 00000000 eaf08fe4 00000000 600d0013 00000000 [ 682.768117] 9e00: c1732e3c c16093a8 e820d4c0 e80e9e28 c018a57c c018b870 600d0013 ffffffff [ 682.776315] [] (__irq_svc) from [] (lock_acquire+0x108/0x4e8) [ 682.783821] [] (lock_acquire) from [] (down_write+0x48/0xa8) [ 682.791242] [] (down_write) from [] (unlink_file_vma+0x24/0x40) [ 682.798922] [] (unlink_file_vma) from [] (free_pgtables+0x34/0xb8) [ 682.806858] [] (free_pgtables) from [] (exit_mmap+0xe4/0x170) [ 682.814361] [] (exit_mmap) from [] (mmput+0x5c/0x110) [ 682.821171] [] (mmput) from [] (do_exit+0x374/0xbe4) [ 682.827892] [] (do_exit) from [] (do_group_exit+0x38/0xb4) [ 682.835132] [] (do_group_exit) from [] (__wake_up_parent+0x0/0x14) [ 682.843063] irq event stamp: 1936 [ 682.846399] hardirqs last enabled at (1935): [] rmqueue+0xf4/0xc64 [ 682.853553] hardirqs last disabled at (1936): [] __irq_svc+0x60/0x98 [ 682.860799] softirqs last enabled at (1878): [] raw_release+0x108/0x1f0 [can_raw] [ 682.869256] softirqs last disabled at (1876): [] release_sock+0x18/0x98 [ 682.876753] ---[ end trace 7bca4751ce44c444 ]--- This patch fixes the problem by replacing the kfree_skb() by dev_kfree_skb_any(), as rx-offload might be called from threaded IRQ handlers as well. Fixes: ca913f1ac024 ("can: rx-offload: can_rx_offload_queue_sorted(): fix error handling, avoid skb mem leak") Fixes: 6caf8a6d6586 ("can: rx-offload: can_rx_offload_queue_tail(): fix error handling, avoid skb mem leak") Signed-off-by: Marc Kleine-Budde --- drivers/net/can/rx-offload.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/can/rx-offload.c b/drivers/net/can/rx-offload.c index 3b180269a92d..6e95193b215b 100644 --- a/drivers/net/can/rx-offload.c +++ b/drivers/net/can/rx-offload.c @@ -245,7 +245,7 @@ int can_rx_offload_queue_sorted(struct can_rx_offload *offload, if (skb_queue_len(&offload->skb_queue) > offload->skb_queue_len_max) { - kfree_skb(skb); + dev_kfree_skb_any(skb); return -ENOBUFS; } @@ -290,7 +290,7 @@ int can_rx_offload_queue_tail(struct can_rx_offload *offload, { if (skb_queue_len(&offload->skb_queue) > offload->skb_queue_len_max) { - kfree_skb(skb); + dev_kfree_skb_any(skb); return -ENOBUFS; } -- 2.28.0