From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 024D7367297 for ; Thu, 17 Sep 2026 01:13:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789607626; cv=none; b=cp8uSoGy+fjKosmUI7eYCWLxgrNlQ6kXVuzfPnlkxlxlYH7jtNol5klt6OIQ7NcQcrZBY2bx9UX6BKUr7pliY7bbLnWKLPM4n4GvgaPfDuR3n+TLg44cNDpm6vH+Un/y+C0KjDH1Q0b4ros0Fe02ytdQwnnmAVwr92r9oV9+ZsE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789607626; c=relaxed/simple; bh=4UATGRPfjlc3E0STF0mXoSMku+QXjtJ/Kr/GlZVgG40=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=F4frYAoCS0n8qgUevgYfklmQmzJTauiVihlW6CV+SVc+YZmDCAViUvPP+WPeybFg7Rbzh0I6bMlJk4AsDqecEStEVVM7WOWoHZ+yorSWxVJ2zArLQ5PcFp71PWRSXGr8KDjJZ2b6vR7P3mXoZYakxN2FTQcQpTLvJ1LKqTpo6fY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aMeixCtl; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="aMeixCtl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 382AC1F00898; Thu, 17 Sep 2026 01:13:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789607621; bh=Eeoi/2Pq7vT5yOJ9iOL+c3h8bjXNYhYEN3atc1NGn0s=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=aMeixCtl1NFm+TMcqRoG3/167Ts8CBqLMocgeW5eUZeIvMhrbgzKLy8vw8PA+uhXU dDVwDu9py9jKfliCRRFgUT3sEf/RZdqd8YVZZKn6gOBV6G0Jz/mhVbAAkEkv/+TDOj X1KkkD9zHcpaBxKV2Q22xuhuaeRhxtbTceRoJjLh8Y0DeHJgvwGycGTQYI0fZ7xcaF wubxL+R3LHF4Ca+CnyPzPUjwpVxWbcFLwG3N911jlC6kKe1a0To8o450sDZaIbF9n7 pWGJyFRrnSePna7IQlmow+U0hxJAfdEkK/5AOimtCDeH84DqwS6v0REAMGylA+9wyr 3cnOTcfaYD+kg== From: Sasha Levin To: stable@vger.kernel.org Cc: Myeonghun Pak , Ijae Kim , Samuel Salin , Tony Nguyen , Sasha Levin Subject: [PATCH 6.12.y 3/3] idpf: disable DIM work before freeing q_vectors Date: Wed, 16 Sep 2026 21:13:37 -0400 Message-ID: <20260917011337.3532754-3-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260917011337.3532754-1-sashal@kernel.org> References: <2026091649-mourner-moonlit-9772@gregkh> <20260917011337.3532754-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Myeonghun Pak [ Upstream commit 7dd4c829bac2916be98a3e34b41daaba7f42b4c4 ] idpf never drains the Tx/Rx DIM works before freeing the memory they live in. tx_dim and rx_dim are embedded in struct idpf_q_vector, they are queued from the NAPI poll via net_dim(), and idpf_vport_intr_rel() ends with kfree(rsrc->q_vectors). Nothing in the driver cancels them. idpf_tx_dim_work() and idpf_rx_dim_work() then run on freed memory: idpf_vport_intr_write_itr() writes the ITR register through q_vector->intr_reg.tx_itr / rx_itr, void __iomem pointers loaded out of the freed q_vector. No configuration is needed to get there -- IDPF_ITR_IS_DYNAMIC() is defined as (itr_mode) and idpf_vport_alloc() initialises both modes to IDPF_ITR_DYNAMIC. Draining after idpf_vport_intr_napi_dis_all() is not enough on its own. idpf_net_dim() is called from inside the "if (napi_complete_done(napi, work_done))" branch of the poll, and napi_complete_done() has already cleared NAPIF_STATE_SCHED by then. napi_disable_locked() waits only while (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)), so napi_disable() can return while the poll tail is still queueing the work, and a plain cancel_work_sync() would be re-armed behind the drain. Use disable_work_sync(): schedule_work() on a work with a non-zero disable count is dropped by clear_pending_if_disabled() before __queue_work() is reached. Move idpf_init_dim() to idpf_vport_intr_alloc() so the works are initialised on every path that can reach the drain -- the three "goto intr_deinit" sites between idpf_vport_intr_init() and idpf_vport_intr_ena() get there without the enable side having run. Nothing re-enables them: rsrc->q_vectors is freed on every exit from idpf_vport_open() and on every idpf_vport_stop(), so the count dies with the object. It is a race, not a deterministic failure -- net_dim() only schedules once DIM_NEVENTS events have accumulated and the profile index changes. A KASAN ifup/ifdown loop under load is the way to see it. Fixes: c2d548cad150 ("idpf: add TX splitq napi poll support") Fixes: 3a8845af66ed ("idpf: add RX splitq napi poll support") Cc: # see patch description, needs adjustments for <= 6.9 Co-developed-by: Ijae Kim Signed-off-by: Ijae Kim Signed-off-by: Myeonghun Pak Tested-by: Samuel Salin Signed-off-by: Tony Nguyen Signed-off-by: Sasha Levin --- drivers/net/ethernet/intel/idpf/idpf_txrx.c | 24 ++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c b/drivers/net/ethernet/intel/idpf/idpf_txrx.c index dc7b482ac0484..2597e86b9adab 100644 --- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c +++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c @@ -3569,6 +3569,26 @@ static void idpf_vport_intr_ena_irq_all(struct idpf_vport *vport, } } +/** + * idpf_vport_intr_dis_dim_all - Disable DIM work for all q_vectors + * @rsrc: pointer to queue and vector resources + * + * The DIM works are embedded in the q_vector array that + * idpf_vport_intr_rel() frees, and the poll arms them after + * napi_complete_done() has already cleared NAPI_STATE_SCHED. Disable + * rather than just cancel, so that a poll tail still running past + * napi_disable() cannot queue them again behind the drain. + */ +static void idpf_vport_intr_dis_dim_all(struct idpf_q_vec_rsrc *rsrc) +{ + for (u16 v_idx = 0; v_idx < rsrc->num_q_vectors; v_idx++) { + struct idpf_q_vector *q_vector = &rsrc->q_vectors[v_idx]; + + disable_work_sync(&q_vector->tx_dim.work); + disable_work_sync(&q_vector->rx_dim.work); + } +} + /** * idpf_vport_intr_deinit - Release all vector associations for the vport * @vport: main vport structure @@ -3579,6 +3599,7 @@ void idpf_vport_intr_deinit(struct idpf_vport *vport, { idpf_vport_intr_dis_irq_all(rsrc); idpf_vport_intr_napi_dis_all(rsrc); + idpf_vport_intr_dis_dim_all(rsrc); idpf_vport_intr_napi_del_all(rsrc); idpf_vport_intr_rel_irq(vport, rsrc); } @@ -3659,7 +3680,6 @@ static void idpf_vport_intr_napi_ena_all(struct idpf_q_vec_rsrc *rsrc) for (u16 q_idx = 0; q_idx < rsrc->num_q_vectors; q_idx++) { struct idpf_q_vector *q_vector = &rsrc->q_vectors[q_idx]; - idpf_init_dim(q_vector); napi_enable(&q_vector->napi); } } @@ -3979,6 +3999,8 @@ int idpf_vport_intr_alloc(struct idpf_vport *vport, q_coal = &user_config->q_coalesce[v_idx]; q_vector->vport = vport; + idpf_init_dim(q_vector); + q_vector->tx_itr_value = q_coal->tx_coalesce_usecs; q_vector->tx_intr_mode = q_coal->tx_intr_mode; q_vector->tx_itr_idx = VIRTCHNL2_ITR_IDX_1; -- 2.53.0