From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-185.mta0.migadu.com (out-185.mta0.migadu.com [91.218.175.185]) (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 61FF6362128 for ; Tue, 24 Mar 2026 08:07:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.185 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774339644; cv=none; b=Scn0ebSLr29CIIyszh6bGnwesq5OPp9iHTeuvZsS2dG8KwvqO+OYSIkxjMumqPf9Gby9h4+se6cznf6QMz/Ta7Oiq6fS/hJ4ARtbnoaQvrK7iPZFXgb/58WkihnE7B+6EpD527wFVBQJ/25UlWSrEBLAHhNJn3ZiyQA6GBwlmSQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774339644; c=relaxed/simple; bh=ZvmDtRtwLXF4NN4xJBAcY7RYMs7JzpNX/mz4Gt1djL8=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=CNsU3Dbz795DwpGwIo/gXfTv+mIkNiKg/VkDswTbtdEFakCT36PWXewjM+Hb7wxBUaPY1kdfu4UQiRCR6uZyFjqfKTZRNL4D7aADAzmKBvI/tmmofCDZkW+Kafq+SgZh4TkV+gDwJzUCDPoeo7o7jgheJdnSrlzvSto0AQQjvho= 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=Ffhy3Yce; arc=none smtp.client-ip=91.218.175.185 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="Ffhy3Yce" 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=1774339628; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=F7Fbu8GvqOu3EypjsQLM9k82uQKOXpR7x4RhsQ7hJIU=; b=Ffhy3Ycem3McJUcsmBWjJdd3jeQEFVP18QFrYPu92V6d07hpGd/zZAPCRs0KuDtJVljLk9 l4k7epMAQrMHEiDPiMewKfHqN7UVF/danxp/zgPClGMw861/6pAuBabk9iWLH/zvlTtPIA TSxF/7LaMF+OoTmZ0FWrwpG0qu9BxPY= From: Jiayuan Chen To: netdev@vger.kernel.org Cc: Jiayuan Chen , syzbot+006987d1be3586e13555@syzkaller.appspotmail.com, Jiayuan Chen , Manivannan Sadhasivam , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Bjorn Andersson , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net v1] net: qrtr: replace qrtr_tx_flow radix_tree with xarray to fix memory leak Date: Tue, 24 Mar 2026 16:06:44 +0800 Message-ID: <20260324080645.290197-1-jiayuan.chen@linux.dev> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT From: Jiayuan Chen __radix_tree_create() allocates and links intermediate nodes into the tree one by one. If a subsequent allocation fails, the already-linked nodes remain in the tree with no corresponding leaf entry. These orphaned internal nodes are never reclaimed because radix_tree_for_each_slot() only visits slots containing leaf values. The radix_tree API is deprecated in favor of xarray. As suggested by Matthew Wilcox, migrate qrtr_tx_flow from radix_tree to xarray instead of fixing the radix_tree itself [1]. xarray properly handles cleanup of internal nodes — xa_destroy() frees all internal xarray nodes when the qrtr_node is released, preventing the leak. [1] https://lore.kernel.org/all/20260225071623.41275-1-jiayuan.chen@linux.dev/T/ Reported-by: syzbot+006987d1be3586e13555@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/000000000000bfba3a060bf4ffcf@google.com/T/ Fixes: 5fdeb0d372ab ("net: qrtr: Implement outgoing flow control") Cc: Jiayuan Chen Signed-off-by: Jiayuan Chen --- net/qrtr/af_qrtr.c | 31 +++++++++++++------------------ 1 file changed, 13 insertions(+), 18 deletions(-) diff --git a/net/qrtr/af_qrtr.c b/net/qrtr/af_qrtr.c index 55fd2dd37588..d77e9c8212da 100644 --- a/net/qrtr/af_qrtr.c +++ b/net/qrtr/af_qrtr.c @@ -118,7 +118,7 @@ static DEFINE_XARRAY_ALLOC(qrtr_ports); * @ep: endpoint * @ref: reference count for node * @nid: node id - * @qrtr_tx_flow: tree of qrtr_tx_flow, keyed by node << 32 | port + * @qrtr_tx_flow: xarray of qrtr_tx_flow, keyed by node << 32 | port * @qrtr_tx_lock: lock for qrtr_tx_flow inserts * @rx_queue: receive queue * @item: list item for broadcast list @@ -129,7 +129,7 @@ struct qrtr_node { struct kref ref; unsigned int nid; - struct radix_tree_root qrtr_tx_flow; + struct xarray qrtr_tx_flow; struct mutex qrtr_tx_lock; /* for qrtr_tx_flow */ struct sk_buff_head rx_queue; @@ -172,6 +172,7 @@ static void __qrtr_node_release(struct kref *kref) struct qrtr_tx_flow *flow; unsigned long flags; void __rcu **slot; + unsigned long index; spin_lock_irqsave(&qrtr_nodes_lock, flags); /* If the node is a bridge for other nodes, there are possibly @@ -189,11 +190,9 @@ static void __qrtr_node_release(struct kref *kref) skb_queue_purge(&node->rx_queue); /* Free tx flow counters */ - radix_tree_for_each_slot(slot, &node->qrtr_tx_flow, &iter, 0) { - flow = *slot; - radix_tree_iter_delete(&node->qrtr_tx_flow, &iter, slot); + xa_for_each(&node->qrtr_tx_flow, index, flow) kfree(flow); - } + xa_destroy(&node->qrtr_tx_flow); kfree(node); } @@ -228,9 +227,7 @@ static void qrtr_tx_resume(struct qrtr_node *node, struct sk_buff *skb) key = remote_node << 32 | remote_port; - rcu_read_lock(); - flow = radix_tree_lookup(&node->qrtr_tx_flow, key); - rcu_read_unlock(); + flow = xa_load(&node->qrtr_tx_flow, key); if (flow) { spin_lock(&flow->resume_tx.lock); flow->pending = 0; @@ -269,12 +266,13 @@ static int qrtr_tx_wait(struct qrtr_node *node, int dest_node, int dest_port, return 0; mutex_lock(&node->qrtr_tx_lock); - flow = radix_tree_lookup(&node->qrtr_tx_flow, key); + flow = xa_load(&node->qrtr_tx_flow, key); if (!flow) { flow = kzalloc_obj(*flow); if (flow) { init_waitqueue_head(&flow->resume_tx); - if (radix_tree_insert(&node->qrtr_tx_flow, key, flow)) { + if (xa_err(xa_store(&node->qrtr_tx_flow, key, flow, + GFP_KERNEL))) { kfree(flow); flow = NULL; } @@ -326,9 +324,7 @@ static void qrtr_tx_flow_failed(struct qrtr_node *node, int dest_node, unsigned long key = (u64)dest_node << 32 | dest_port; struct qrtr_tx_flow *flow; - rcu_read_lock(); - flow = radix_tree_lookup(&node->qrtr_tx_flow, key); - rcu_read_unlock(); + flow = xa_load(&node->qrtr_tx_flow, key); if (flow) { spin_lock_irq(&flow->resume_tx.lock); flow->tx_failed = 1; @@ -599,7 +595,7 @@ int qrtr_endpoint_register(struct qrtr_endpoint *ep, unsigned int nid) node->nid = QRTR_EP_NID_AUTO; node->ep = ep; - INIT_RADIX_TREE(&node->qrtr_tx_flow, GFP_KERNEL); + xa_init(&node->qrtr_tx_flow); mutex_init(&node->qrtr_tx_lock); qrtr_node_assign(node, nid); @@ -627,6 +623,7 @@ void qrtr_endpoint_unregister(struct qrtr_endpoint *ep) struct qrtr_tx_flow *flow; struct sk_buff *skb; unsigned long flags; + unsigned long index; void __rcu **slot; mutex_lock(&node->ep_lock); @@ -649,10 +646,8 @@ void qrtr_endpoint_unregister(struct qrtr_endpoint *ep) /* Wake up any transmitters waiting for resume-tx from the node */ mutex_lock(&node->qrtr_tx_lock); - radix_tree_for_each_slot(slot, &node->qrtr_tx_flow, &iter, 0) { - flow = *slot; + xa_for_each(&node->qrtr_tx_flow, index, flow) wake_up_interruptible_all(&flow->resume_tx); - } mutex_unlock(&node->qrtr_tx_lock); qrtr_node_release(node); -- 2.43.0