From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Maurizio Lombardi <mlombard@redhat.com>,
        Sagi Grimberg <sagi@grimberg.me>,
        John Meneghini <jmeneghi@redhat.com>,
        Christoph Hellwig <hch@lst.de>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 050/355] nvmet-tcp: fix a memory leak when releasing a queue
Date:   Mon, 15 Nov 2021 17:59:34 +0100
Message-Id: <20211115165315.167486124@linuxfoundation.org>
In-Reply-To: <20211115165313.549179499@linuxfoundation.org>
References: <20211115165313.549179499@linuxfoundation.org>
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From: Maurizio Lombardi <mlombard@redhat.com>

[ Upstream commit 926245c7d22271307606c88b1fbb2539a8550e94 ]

page_frag_free() won't completely release the memory
allocated for the commands, the cache page must be explicitly
freed by calling __page_frag_cache_drain().

This bug can be easily reproduced by repeatedly
executing the following command on the initiator:

$echo 1 > /sys/devices/virtual/nvme-fabrics/ctl/nvme0/reset_controller

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: John Meneghini <jmeneghi@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/nvme/target/tcp.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index 2f4e512bd449f..1328ee373e596 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -1343,6 +1343,7 @@ static void nvmet_tcp_uninit_data_in_cmds(struct nvmet_tcp_queue *queue)
 
 static void nvmet_tcp_release_queue_work(struct work_struct *w)
 {
+	struct page *page;
 	struct nvmet_tcp_queue *queue =
 		container_of(w, struct nvmet_tcp_queue, release_work);
 
@@ -1362,6 +1363,8 @@ static void nvmet_tcp_release_queue_work(struct work_struct *w)
 		nvmet_tcp_free_crypto(queue);
 	ida_simple_remove(&nvmet_tcp_queue_ida, queue->idx);
 
+	page = virt_to_head_page(queue->pf_cache.va);
+	__page_frag_cache_drain(page, queue->pf_cache.pagecnt_bias);
 	kfree(queue);
 }
 
-- 
2.33.0