linux-kernel - [PATCH v6 08/14] nvmet-fcloop: prevent double port deletion

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250507-nvmet-fcloop-v6-8-ca02e16fb018@kernel.org>
Date: Wed, 07 May 2025 14:23:04 +0200
From: Daniel Wagner <wagi@...nel.org>
To: James Smart <james.smart@...adcom.com>, Christoph Hellwig <hch@....de>, 
 Sagi Grimberg <sagi@...mberg.me>, Chaitanya Kulkarni <kch@...dia.com>
Cc: Hannes Reinecke <hare@...e.de>, Keith Busch <kbusch@...nel.org>, 
 linux-nvme@...ts.infradead.org, linux-kernel@...r.kernel.org, 
 Daniel Wagner <wagi@...nel.org>
Subject: [PATCH v6 08/14] nvmet-fcloop: prevent double port deletion

The delete callback can be called either via the unregister function or
from the transport directly. Thus it is necessary ensure resources are
not freed multiple times.

Signed-off-by: Daniel Wagner <wagi@...nel.org>
---
 drivers/nvme/target/fcloop.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/target/fcloop.c b/drivers/nvme/target/fcloop.c
index 9adaee3c7129f7e270842c5d09f78de2e108479a..c74baa7f6e43c8bddd9e6948f806f27b032b1d4d 100644
--- a/drivers/nvme/target/fcloop.c
+++ b/drivers/nvme/target/fcloop.c
@@ -215,6 +215,9 @@ struct fcloop_lport_priv {
 	struct fcloop_lport *lport;
 };
 
+/* The port is already being removed, avoid double free */
+#define PORT_DELETED	0
+
 struct fcloop_rport {
 	struct nvme_fc_remote_port	*remoteport;
 	struct nvmet_fc_target_port	*targetport;
@@ -223,6 +226,7 @@ struct fcloop_rport {
 	spinlock_t			lock;
 	struct list_head		ls_list;
 	struct work_struct		ls_work;
+	unsigned long			flags;
 };
 
 struct fcloop_tport {
@@ -233,6 +237,7 @@ struct fcloop_tport {
 	spinlock_t			lock;
 	struct list_head		ls_list;
 	struct work_struct		ls_work;
+	unsigned long			flags;
 };
 
 struct fcloop_nport {
@@ -1067,30 +1072,38 @@ static void
 fcloop_remoteport_delete(struct nvme_fc_remote_port *remoteport)
 {
 	struct fcloop_rport *rport = remoteport->private;
+	bool put_port = false;
 	unsigned long flags;
 
 	flush_work(&rport->ls_work);
 
 	spin_lock_irqsave(&fcloop_lock, flags);
+	if (!test_and_set_bit(PORT_DELETED, &rport->flags))
+		put_port = true;
 	rport->nport->rport = NULL;
 	spin_unlock_irqrestore(&fcloop_lock, flags);
 
-	fcloop_nport_put(rport->nport);
+	if (put_port)
+		fcloop_nport_put(rport->nport);
 }
 
 static void
 fcloop_targetport_delete(struct nvmet_fc_target_port *targetport)
 {
 	struct fcloop_tport *tport = targetport->private;
+	bool put_port = false;
 	unsigned long flags;
 
 	flush_work(&tport->ls_work);
 
 	spin_lock_irqsave(&fcloop_lock, flags);
+	if (!test_and_set_bit(PORT_DELETED, &tport->flags))
+		put_port = true;
 	tport->nport->tport = NULL;
 	spin_unlock_irqrestore(&fcloop_lock, flags);
 
-	fcloop_nport_put(tport->nport);
+	if (put_port)
+		fcloop_nport_put(tport->nport);
 }
 
 #define	FCLOOP_HW_QUEUES		4
@@ -1433,6 +1446,7 @@ fcloop_create_remote_port(struct device *dev, struct device_attribute *attr,
 	rport->nport = nport;
 	rport->lport = nport->lport;
 	nport->rport = rport;
+	rport->flags = 0;
 	spin_lock_init(&rport->lock);
 	INIT_WORK(&rport->ls_work, fcloop_rport_lsrqst_work);
 	INIT_LIST_HEAD(&rport->ls_list);
@@ -1530,6 +1544,7 @@ fcloop_create_target_port(struct device *dev, struct device_attribute *attr,
 	tport->nport = nport;
 	tport->lport = nport->lport;
 	nport->tport = tport;
+	tport->flags = 0;
 	spin_lock_init(&tport->lock);
 	INIT_WORK(&tport->ls_work, fcloop_tport_lsrqst_work);
 	INIT_LIST_HEAD(&tport->ls_list);

-- 
2.49.0