From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-171.mta0.migadu.com (out-171.mta0.migadu.com [91.218.175.171]) (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 3FFDE42DA5D for ; Tue, 11 Aug 2026 10:39:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786444753; cv=none; b=jscXYE1C5THhWk+8Xc4aQ1ESE1fjUApQCxq4JhCU64hNu8MHlbS4eHtUebcvzYQtUtbGkiCZq7/9ySfUa3vZjru4IZTRuK2xr59oqpplxyHcoJW9r1RUBNyeCkklV8CQjSp6yQ+8TkF5hT5KWK0yUKgtNdYBbEKVy4wulBP40os= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786444753; c=relaxed/simple; bh=2ZHwp6+DisNJlZr/Ej+2cYjgEhwlm8PU0xfq5F2VDjM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ufN/Ev0U6H7OnrixF+4z+eLs2C+E8hjajIEZXN2DG+UuKdGx+3v7Pc5R5/++1xEg3FnklWG2DEHSQX5taOTh4Gs7afTm6nNfDcP9cLXJZvJ1AoaJY9hgZfef287ORqRaMBEO3m1+4x5BNZil/y3uN2RGVT6yGFpOubF/hkdR4dM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=rkeAkIcp; arc=none smtp.client-ip=91.218.175.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="rkeAkIcp" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1786444749; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iZf/htlsFgNcS+35IOEXNe4Ql4XRBRXaDRHFFsmjgFk=; b=rkeAkIcpG7i6F6Da1VVGpMnMNEA1FMzDR5zLIJdOeYNrbe9x7Si6Fe+VZj9Ci2r9FLNRL4 rgFxtJsuz2M65j898+hhxlWamS+i4MVySM5+orZ2YNxezU2rw41XWLHLRGW3rTgGbChcbc OaqxjqkWMkKPqb7AMc0AjxAKi00XMgo= From: Xuanqiang Luo To: linux-renesas-soc@vger.kernel.org, netdev@vger.kernel.org, niklas.soderlund@ragnatech.se, kuba@kernel.org, vadim.fedorenko@linux.dev Cc: paul@pbarker.dev, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, richardcochran@gmail.com, masaru.nagai.vx@renesas.com, luoxuanqiang@kylinos.cn, stable@vger.kernel.org Subject: [PATCH net v4 2/2] net: ravb: serialize PTP clock teardown Date: Tue, 11 Aug 2026 18:37:33 +0800 Message-ID: <20260811103733.62599-3-xuanqiang.luo@linux.dev> In-Reply-To: <20260811103733.62599-1-xuanqiang.luo@linux.dev> References: <20260811103733.62599-1-xuanqiang.luo@linux.dev> Precedence: bulk X-Mailing-List: linux-renesas-soc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT From: Xuanqiang Luo ravb_ptp_interrupt() can race with ravb_ptp_stop() and pass the clock to ptp_clock_event() while ptp_clock_unregister() is freeing it. This can lead to a use-after-free. Use READ_ONCE() and WRITE_ONCE() for lockless access to the clock pointer. Atomically detach it with xchg() before disabling PTP interrupts, then synchronize all IRQs which can invoke ravb_ptp_interrupt() before unregistering the detached clock. A handler which read the old pointer completes before the clock is unregistered, while later handlers read NULL and skip the event. Fixes: a0d2f20650e8 ("Renesas Ethernet AVB PTP clock driver") Cc: stable@vger.kernel.org Signed-off-by: Xuanqiang Luo --- drivers/net/ethernet/renesas/ravb.h | 2 ++ drivers/net/ethernet/renesas/ravb_main.c | 6 ++-- drivers/net/ethernet/renesas/ravb_ptp.c | 37 +++++++++++++++++++----- 3 files changed, 35 insertions(+), 10 deletions(-) diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h index 2a4fcb12a63cb..3ee4c61081890 100644 --- a/drivers/net/ethernet/renesas/ravb.h +++ b/drivers/net/ethernet/renesas/ravb.h @@ -1124,6 +1124,8 @@ struct ravb_private { int msg_enable; int speed; int emac_irq; + int err_irq; + int mgmt_irq; unsigned no_avb_link:1; unsigned avb_link_active_low:1; diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c index db0229e008494..ea1c7e536791e 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c @@ -2885,11 +2885,13 @@ static int ravb_setup_irqs(struct ravb_private *priv) return error; if (info->err_mgmt_irqs) { - error = ravb_setup_irq(priv, "err_a", "err_a", NULL, ravb_multi_interrupt); + error = ravb_setup_irq(priv, "err_a", "err_a", &priv->err_irq, + ravb_multi_interrupt); if (error) return error; - error = ravb_setup_irq(priv, "mgmt_a", "mgmt_a", NULL, ravb_multi_interrupt); + error = ravb_setup_irq(priv, "mgmt_a", "mgmt_a", &priv->mgmt_irq, + ravb_multi_interrupt); if (error) return error; } diff --git a/drivers/net/ethernet/renesas/ravb_ptp.c b/drivers/net/ethernet/renesas/ravb_ptp.c index cbec7c057d715..43218bc15b151 100644 --- a/drivers/net/ethernet/renesas/ravb_ptp.c +++ b/drivers/net/ethernet/renesas/ravb_ptp.c @@ -289,16 +289,17 @@ static const struct ptp_clock_info ravb_ptp_info = { void ravb_ptp_interrupt(struct net_device *ndev) { struct ravb_private *priv = netdev_priv(ndev); + struct ptp_clock *clock = READ_ONCE(priv->ptp.clock); u32 gis = ravb_read(ndev, GIS); gis &= ravb_read(ndev, GIC); - if (gis & GIS_PTCF) { + if ((gis & GIS_PTCF) && clock) { struct ptp_clock_event event; event.type = PTP_CLOCK_EXTTS; event.index = 0; event.timestamp = ravb_read(ndev, GCPT); - ptp_clock_event(priv->ptp.clock, &event); + ptp_clock_event(clock, &event); } if (gis & GIS_PTMF) { struct ravb_ptp_perout *perout = priv->ptp.perout; @@ -334,19 +335,39 @@ void ravb_ptp_init(struct net_device *ndev, struct platform_device *pdev) clock = NULL; } - priv->ptp.clock = clock; + WRITE_ONCE(priv->ptp.clock, clock); if (clock) WRITE_ONCE(priv->ptp.phc_index, ptp_clock_index(clock)); } -void ravb_ptp_stop(struct net_device *ndev) +static void ravb_ptp_disable(struct net_device *ndev) { - struct ravb_private *priv = netdev_priv(ndev); - ravb_write(ndev, 0, GIC); ravb_write(ndev, 0, GIS); +} + +static void ravb_ptp_sync_irqs(struct net_device *ndev) +{ + struct ravb_private *priv = netdev_priv(ndev); + + synchronize_irq(ndev->irq); + if (priv->info->err_mgmt_irqs) { + synchronize_irq(priv->err_irq); + synchronize_irq(priv->mgmt_irq); + } +} + +void ravb_ptp_stop(struct net_device *ndev) +{ + struct ravb_private *priv = netdev_priv(ndev); + struct ptp_clock *clock; WRITE_ONCE(priv->ptp.phc_index, -1); - if (priv->ptp.clock) - ptp_clock_unregister(priv->ptp.clock); + clock = xchg(&priv->ptp.clock, NULL); + + ravb_ptp_disable(ndev); + ravb_ptp_sync_irqs(ndev); + + if (clock) + ptp_clock_unregister(clock); } -- 2.43.0