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=1794585680; b=FTVSt41K7QTDvECoArQTgLCf5VCxjm6/N1e7RVY8JZVpPrLcKbBVoJOrBjvT3eE+IFHz pKM9XIH89oXl4XPujZZLrcG8TIfyREtVImsf4MWVKwBjadP5Lu88YIDMr6Tm7EAV2oewq rg0Z86Bu6QglCalJhzsBXc4UYl8sDFDGn4DLy2lT6Iql6hu2csI5xvVYZs76ahFZsNZeh j6DM7K0fbhUmGscXpLEHAzIntkJCTas8EKUEr7egqDFrumu3THg8BEc0xtqKVXwkjHK3P EGvOuomD3WL+CY1Hw+sBIIU8rZJilQgOo683vwXyfob21N94m43auai486hwugkS+YA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794585680; 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=YRlO7cE2VvdCYBWJs9SkFrMzsC9aIb6qhSp+tf+ZpO4=; b=RI9C7jxpjbzFnd55S+C/MI5UMmtWK9W9/Q8lsLkCvhUAVbK4g5WA0PZDD/oYUVIq6UUh jXqEfn5yR9H30RUnd1t5b9ZRu9aqdSB4AquXr+tGbv2MXzATGsi0VVsqXAYdrTLcoVia/ 2E64YYIvnd/Nkfo9faSHTEG31lYg9W/+EjjAlM/TYaWvrxVJ4enqWEM/iUQf3UQUcJZKs Sb/9U4qQnDxC5ieILdOXux3KuURQMQPo6jn5EC4vGaUHngj26LhxfaErjQmriQ/j7wOBf /FYqB3+R6yhXZCYmoviTP0riFe90uyEYaO1Mtj2ozLV/LZxKsQmiay3q93+vhaovWWg== 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=P2leMcbT; 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 68E6B606A88F; Fri, 13 Nov 2026 16:01:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=P2leMcbT Received: by smtp.kernel.org (Postfix) with ESMTPSA id 14DE31F000C4; Fri, 13 Nov 2026 16:01:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794585680; bh=YRlO7cE2VvdCYBWJs9SkFrMzsC9aIb6qhSp+tf+ZpO4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=P2leMcbT+J6lL3NIRiYPBYiSMVgr7YUDL82F3omQkfDdPAgjsl43xfRoZFEVP4Lsp yscatVKvMMIOi0Bg83L4cUIaXniCWUNe1FfR0GB57C+3nCWtweu14STDPhp71QnShr ISqx72iK0qn7OIGcMhelLkU5oKriWWbaKLjSY/cQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Cunhao Lu <1579567540@qq.com>, stable@kernel.org, Marc Kleine-Budde , Sasha Levin Subject: [PATCH 7.3 292/507] can: skb: make echo skb freeing safe in any IRQ context Date: Fri, 13 Nov 2026 10:49:56 -0500 Message-ID: <20261113153805.149696581@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153753.358973689@linuxfoundation.org> References: <20261113153753.358973689@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore 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-Transfer-Encoding: 8bit 7.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Cunhao Lu <1579567540@qq.com> [ Upstream commit d743071964920c92af598c87a9e6f4369263ee09 ] 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] Signed-off-by: Sasha Levin --- 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