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=1794273196; b=INx1jlwbX0Uf24OSwMy6ChF1fqqj5mZZEt5hAA5wn8tPZKAcQowOYc9J0tRFkMZzML7s gogRL2ly6jbMcmE9m8SEpfWI4dNEgkXshF1qifbQzp5U6/v03hx+FJk1S4mx2Jr4z0gdz Ufj1IDmKoMVLbjemuh8GXnqH/IdfKPZhPTbGLv+0L1LSmNGK120pe9qFXqgNhY9h2i+OZ x4sVGBNcHivatPBrwliZvZXtKY7UtNLXZ4u4wmMbRoj6hW4e1TH5ge/NoITK5Bsn8/cTG 71zGtQCVRsCqa3oneb3Kd9UQoEbHSqJrBmu8srGTqJyCPbRaIVJa/e1jY2VYdp5A6Iw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794273196; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=WY4rDOpVu9vhFPjRr23e0MsM1xwu6+LY4mvEkCx+p+c=; b=TcUxN43X6F5hRZUsr7z5ARIWkrmGEGD5wrl4Zwac2Ij0wuLG2wDeE2TbAlZRz162mnSI TX6Yub1LxtG2snucTwZfiFtQE06JDEy/Y6/klWhs72ob23xoyCpN2v+0br1tdWWKfbYxU ldyuj/8mUtLSUFB3wqmTIVMNoNHL/t+BIy3ELrQUoH0WNKb0VUwZlMPCAdfwgli5028oE vbMjDtdJwF9uyyPAOT3zz6tJBhSJMGbKsCkLzSGK4KELwQDQl4paVywckYkMraN3J0TU6 SU5/DqmrgnZU6nuMJh4Scap/8o1HE3j/bJqWPZgTlM8myAmBFaTLT7R9jsl2YAm7BnA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=CPif2tOa; 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 D0DC8606A31C for ; Tue, 10 Nov 2026 01:13:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=CPif2tOa Received: by smtp.kernel.org (Postfix) with ESMTPSA id 462BC1F0089F; Tue, 10 Nov 2026 01:13:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794273195; bh=WY4rDOpVu9vhFPjRr23e0MsM1xwu6+LY4mvEkCx+p+c=; h=From:To:Cc:Subject:Date; b=CPif2tOa0fZniT/QJqKgocPiT/nWRXUnDKArWHWY1kbFipSplt0TPA+BWu45rQVUr t+pexsxVPZpceqe4sd8mAsz9AJc4PB7zpKioDkbJiyNV+LbrwHzUtKXwhAyoPZ6Elt yOQd1JSPeZ0UgjHQ+aAbSntIFT9pIZogyNxxkyxmN4BSsZzpJpvAgC/dMbRrNyhCx2 E4x/GXXt18fKatHAjQpKeOL2CPugVvTjxlBeDSWKDNkv8eNmtnQN6+X1H8MwFXFitl fDJlrDyQ1b6mqoDzgQzCK0nFYm02qlgUp17J56bDdMkSuDRwtwGoVgeqjZFCmn+mMW A+Xx5Uj+5gYAw== From: Sasha Levin To: 1579567540@qq.com, mkl@pengutronix.de Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] can: skb: make echo skb freeing safe in any IRQ context" failed to apply to 6.6-stable tree Date: Mon, 9 Nov 2026 20:13:14 -0500 Message-ID: <20261109201314-failed-6.6-d74307196492@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x d743071964920c92af598c87a9e6f4369263ee09 # git commit -s git send-email --to '' --in-reply-to '20261109201314-failed-6.6-d74307196492@kernel.org' --subject-prefix 'PATCH 6.6.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From d743071964920c92af598c87a9e6f4369263ee09 Mon Sep 17 00:00:00 2001 From: Cunhao Lu <1579567540@qq.com> Date: Fri, 31 Jul 2026 17:45:00 +0800 Subject: [PATCH] can: skb: make echo skb freeing safe in any IRQ context can_put_echo_skb() can be called with hardware interrupts disabled. Its direct drop paths use kfree_skb(), while can_create_echo_skb() uses kfree_skb() when cloning fails and consume_skb() after a successful clone. None of these helpers is safe in every IRQ context. Use dev_kfree_skb_any() for all drop paths and dev_consume_skb_any() when consuming a successfully cloned skb. This preserves the respective skb drop and consumed semantics regardless of the caller IRQ context. Signed-off-by: Cunhao Lu <1579567540@qq.com> Link: https://patch.msgid.link/tencent_E84809CF236D0137885E7E4E4D58340B3208@qq.com Cc: stable@kernel.org Fixes: ae64438be192 ("can: dev: fix skb drop check") Fixes: 0ae89beb283a ("can: add destructor for self generated skbs") Fixes: 3ccd4c6167d3 ("can: Unify droping of invalid tx skbs and netdev stats") Fixes: 39549eef3587 ("can: CAN Network device driver and Netlink interface") [mkl: also convert can_dropped_invalid_skb(), can_dev_dropped_skb()] [mkl: add stable on Cc + add Fixes tags] Signed-off-by: Marc Kleine-Budde --- FAQ: Q: What about the comment in drivers/net/can/virtio_can.c virtio_can_start_xmit()? The error handling for virtqueue_add_sgs() mentions that can_put_echo_skb() consumes the skb via consume_skb(). A: The comment in virtio_can.c will be updated in a separate series, to ease backporting of this patch. [mkl: add FAQ section] --- drivers/net/can/dev/skb.c | 6 +++--- include/linux/can/dev.h | 2 +- include/linux/can/skb.h | 4 ++-- 3 files changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c index bc0787535b524..46c151eece8f7 100644 --- a/drivers/net/can/dev/skb.c +++ b/drivers/net/can/dev/skb.c @@ -63,7 +63,7 @@ int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, (skb->protocol != htons(ETH_P_CAN) && skb->protocol != htons(ETH_P_CANFD) && skb->protocol != htons(ETH_P_CANXL))) { - kfree_skb(skb); + dev_kfree_skb_any(skb); return 0; } @@ -91,7 +91,7 @@ int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, } else { /* locking problem with netif_stop_queue() ?? */ netdev_err(dev, "%s: BUG! echo_skb %d is occupied!\n", __func__, idx); - kfree_skb(skb); + dev_kfree_skb_any(skb); return -EBUSY; } @@ -403,7 +403,7 @@ bool can_dropped_invalid_skb(struct net_device *dev, struct sk_buff *skb) return false; inval_skb: - kfree_skb(skb); + dev_kfree_skb_any(skb); dev->stats.tx_dropped++; return true; } diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h index 6d0710d6f571d..346faddee02eb 100644 --- a/include/linux/can/dev.h +++ b/include/linux/can/dev.h @@ -176,7 +176,7 @@ static inline bool can_dev_dropped_skb(struct net_device *dev, struct sk_buff *s return can_dropped_invalid_skb(dev, skb); invalid_skb: - kfree_skb(skb); + dev_kfree_skb_any(skb); dev->stats.tx_dropped++; return true; } diff --git a/include/linux/can/skb.h b/include/linux/can/skb.h index 5d27843862fca..87ace09c0d8bd 100644 --- a/include/linux/can/skb.h +++ b/include/linux/can/skb.h @@ -78,12 +78,12 @@ static inline struct sk_buff *can_create_echo_skb(struct sk_buff *skb) nskb = skb_clone(skb, GFP_ATOMIC); if (unlikely(!nskb)) { - kfree_skb(skb); + dev_kfree_skb_any(skb); return NULL; } can_skb_set_owner(nskb, skb->sk); - consume_skb(skb); + dev_consume_skb_any(skb); return nskb; } -- 2.53.0