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 4089C52B1FE; Wed, 23 Sep 2026 14:37:11 +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=1790174232; cv=none; b=m4sghPXHTKHp6AjtKrfijCyP+dBWfE1K8tZ18YochUnmg2DMH4q6NZ7U9GkN03ia9QiAIzigr5M8xqY+kv8/f4ve7qvkFXMqF4VinoMJBj6Yc1GQe4Pv/DrbXClN49IomrsLTfd+w/yyVWg3kDmx1iOHN7J4oFyDn/u2Of2tihY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790174232; c=relaxed/simple; bh=0Y/f3n9l4eTuhec2OreWzzClfw1Wh8SpRvKFa93ZkvE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Nixaj8HABtVRpLB33gu4W/zDESk4Q0JE53N17ulKK5M0lPn8LOHeWXCRZdKQhF2I7LA2fBFGwfk3QdmTeCnzXaPruZRMbQuPfve52eF/sqysL4zsq1HThMMo8xzJRk26kDo/Z+X2agOHJK+aQJD8Ny3yzX1a/5M0QvN9dEeTLRE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=cHfshzyF; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="cHfshzyF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 96A051F000FF; Wed, 23 Sep 2026 14:37:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790174231; bh=oJ2sDe+qJo2EDAT/EkEjadhA1uG9owBfrLkDH4X79+0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=cHfshzyFq51uT4gG9O+03GHFNqey9HrFG+9+Ax6J+9zlKgFzXkLxtShAWkFLXNkZ3 yXdOWdOzIrKNExuX/+mmdQnBknx2lpYrpLQ2qgSmS8dh9Z9D4yKFfyTk2c5GUpawxp 2pNqLl2zYGOGFKGvQk8xwRxK77m+aQyRZLkGsOu4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ben Davies , Carolina Jubran , Cosmin Ratiu , Edward Srouji , Leon Romanovsky , Sasha Levin Subject: [PATCH 6.18 050/398] IB/IPoIB: Avoid restoring OPER_UP after multicast flush Date: Wed, 23 Sep 2026 16:02:04 +0200 Message-ID: <20260923140644.717761680@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260923140643.441954610@linuxfoundation.org> References: <20260923140643.441954610@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Carolina Jubran [ Upstream commit 9a141d3dc869d18b2eab35e999f4790a9b84e40f ] ipoib_ib_dev_flush_light() temporarily clears IPOIB_FLAG_OPER_UP to prevent multicast joins while ipoib_mcast_dev_flush() is running, and restores the flag afterwards if it was previously set. This restore races with ipoib_ib_dev_down(). If the interface is brought down while the flush is in progress, ipoib_ib_dev_down() clears IPOIB_FLAG_OPER_UP, but the flush path may set it again after the device has already gone down. Since commit 894021a75291 ("IB/ipoib: Make the carrier_on_task race aware"), ipoib_mcast_carrier_on_task() relies on IPOIB_FLAG_OPER_UP being cleared to terminate its rtnl_trylock() retry loop. If the flag is left set after shutdown, the workqueue retries forever, causing teardown to deadlock when ipoib_ndo_uninit() waits in destroy_workqueue() while holding RTNL. Instead of overloading IPOIB_FLAG_OPER_UP to block multicast joins during a light flush, introduce a dedicated IPOIB_FLAG_MCAST_FLUSH flag. Use it together with IPOIB_FLAG_OPER_UP to determine whether multicast joins are allowed, avoiding the race with device shutdown. Fixes: 344bacca8cd8 ("IB/ipoib: Don't allow MC joins during light MC flush") Reported-by: Ben Davies Signed-off-by: Carolina Jubran Reviewed-by: Cosmin Ratiu Signed-off-by: Edward Srouji Link: https://patch.msgid.link/20260902-avoid-rest-oper-up-v1-1-04fcd4916cae@nvidia.com Signed-off-by: Leon Romanovsky Signed-off-by: Sasha Levin --- drivers/infiniband/ulp/ipoib/ipoib.h | 7 +++++++ drivers/infiniband/ulp/ipoib/ipoib_ib.c | 12 +++++++----- drivers/infiniband/ulp/ipoib/ipoib_multicast.c | 16 ++++++++-------- 3 files changed, 22 insertions(+), 13 deletions(-) diff --git a/drivers/infiniband/ulp/ipoib/ipoib.h b/drivers/infiniband/ulp/ipoib/ipoib.h index 91f866e3fb8bd..143e03b649021 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib.h +++ b/drivers/infiniband/ulp/ipoib/ipoib.h @@ -87,6 +87,7 @@ enum { IPOIB_FLAG_INITIALIZED = 1, IPOIB_FLAG_ADMIN_UP = 2, IPOIB_PKEY_ASSIGNED = 3, + IPOIB_FLAG_MCAST_FLUSH = 4, IPOIB_FLAG_SUBINTERFACE = 5, IPOIB_STOP_REAPER = 7, IPOIB_FLAG_ADMIN_CM = 9, @@ -414,6 +415,12 @@ struct ipoib_dev_priv { const struct net_device_ops *rn_ops; }; +static inline bool ipoib_mcast_allowed(struct ipoib_dev_priv *priv) +{ + return test_bit(IPOIB_FLAG_OPER_UP, &priv->flags) && + !test_bit(IPOIB_FLAG_MCAST_FLUSH, &priv->flags); +} + struct ipoib_ah { struct net_device *dev; struct ib_ah *ah; diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ib.c b/drivers/infiniband/ulp/ipoib/ipoib_ib.c index 10b0dbda6cd53..8d9aa75b83206 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_ib.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_ib.c @@ -1227,17 +1227,19 @@ static void __ipoib_ib_dev_flush(struct ipoib_dev_priv *priv, } if (level == IPOIB_FLUSH_LIGHT) { - int oper_up; ipoib_mark_paths_invalid(dev); - /* Set IPoIB operation as down to prevent races between: + /* Set MCAST_FLUSH to prevent races between: * the flush flow which leaves MCG and on the fly joins * which can happen during that time. mcast restart task * should deal with join requests we missed. + * + * Do not clear OPER_UP for this; restoring it races with + * ipoib_ib_dev_down() and can leave OPER_UP set after the + * device is down. */ - oper_up = test_and_clear_bit(IPOIB_FLAG_OPER_UP, &priv->flags); + set_bit(IPOIB_FLAG_MCAST_FLUSH, &priv->flags); ipoib_mcast_dev_flush(dev); - if (oper_up) - set_bit(IPOIB_FLAG_OPER_UP, &priv->flags); + clear_bit(IPOIB_FLAG_MCAST_FLUSH, &priv->flags); ipoib_reap_dead_ahs(priv); } diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c index 8a4ab9ff0a681..4f7639bbc7dc5 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c @@ -74,7 +74,7 @@ static void __ipoib_mcast_schedule_join_thread(struct ipoib_dev_priv *priv, struct ipoib_mcast *mcast, bool delay) { - if (!test_bit(IPOIB_FLAG_OPER_UP, &priv->flags)) + if (!ipoib_mcast_allowed(priv)) return; /* @@ -469,7 +469,7 @@ static int ipoib_mcast_join(struct net_device *dev, struct ipoib_mcast *mcast) int ret = 0; if (!priv->broadcast || - !test_bit(IPOIB_FLAG_OPER_UP, &priv->flags)) + !ipoib_mcast_allowed(priv)) return -EINVAL; init_completion(&mcast->done); @@ -555,7 +555,7 @@ void ipoib_mcast_join_task(struct work_struct *work) unsigned long delay_until = 0; struct ipoib_mcast *mcast = NULL; - if (!test_bit(IPOIB_FLAG_OPER_UP, &priv->flags)) + if (!ipoib_mcast_allowed(priv)) return; if (ib_query_port(priv->ca, priv->port, &port_attr)) { @@ -577,7 +577,7 @@ void ipoib_mcast_join_task(struct work_struct *work) netif_addr_unlock_bh(dev); spin_lock_irq(&priv->lock); - if (!test_bit(IPOIB_FLAG_OPER_UP, &priv->flags)) + if (!ipoib_mcast_allowed(priv)) goto out; if (!priv->broadcast) { @@ -749,7 +749,7 @@ void ipoib_mcast_send(struct net_device *dev, u8 *daddr, struct sk_buff *skb) spin_lock_irqsave(&priv->lock, flags); - if (!test_bit(IPOIB_FLAG_OPER_UP, &priv->flags) || + if (!ipoib_mcast_allowed(priv) || !priv->broadcast || !test_bit(IPOIB_MCAST_FLAG_ATTACHED, &priv->broadcast->flags)) { ++dev->stats.tx_dropped; @@ -871,7 +871,7 @@ void ipoib_mcast_restart_task(struct work_struct *work) LIST_HEAD(remove_list); struct ib_sa_mcmember_rec rec; - if (!test_bit(IPOIB_FLAG_OPER_UP, &priv->flags)) + if (!ipoib_mcast_allowed(priv)) /* * shortcut...on shutdown flush is called next, just * let it do all the work @@ -965,9 +965,9 @@ void ipoib_mcast_restart_task(struct work_struct *work) ipoib_mcast_remove_list(&remove_list); /* - * Double check that we are still up + * Double check that we are still up and not flushing */ - if (test_bit(IPOIB_FLAG_OPER_UP, &priv->flags)) { + if (ipoib_mcast_allowed(priv)) { spin_lock_irq(&priv->lock); __ipoib_mcast_schedule_join_thread(priv, NULL, 0); spin_unlock_irq(&priv->lock); -- 2.53.0