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From:   Zhipeng Lu <alexious@zju.edu.cn>
To:     alexious@zju.edu.cn
Cc:     Sunil Goutham <sgoutham@marvell.com>,
        Linu Cherian <lcherian@marvell.com>,
        Geetha sowjanya <gakula@marvell.com>,
        Jerin Jacob <jerinj@marvell.com>,
        hariprasad <hkelam@marvell.com>,
        Subbaraya Sundeep <sbhatta@marvell.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        George Cherian <george.cherian@marvell.com>,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] octeontx2-af: fix a use-after-free in rvu_npa_register_reporters
Date:   Sat,  2 Dec 2023 17:59:02 +0800
Message-Id: <20231202095902.3264863-1-alexious@zju.edu.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The rvu_dl will be freed in rvu_npa_health_reporters_destroy(rvu_dl)
after the create_workqueue fails, and after that free, the rvu_dl will
be translate back through rvu_npa_health_reporters_create,
rvu_health_reporters_create, and rvu_register_dl. Finally it goes to the
err_dl_health label, being freed again in
rvu_health_reporters_destroy(rvu) by rvu_npa_health_reporters_destroy.
In the second calls of rvu_npa_health_reporters_destroy, however,
it uses rvu_dl->rvu_npa_health_reporter, which is already freed at
the end of rvu_npa_health_reporters_destroy in the first call.

So this patch prevents the first destroy by instantly returning -ENONMEN
when create_workqueue fails. In addition, since the failure of
create_workqueue is the only entrence of label err, it has been
integrated into the error-handling path of create_workqueue.

Fixes: f1168d1e207c ("octeontx2-af: Add devlink health reporters for NPA")
Signed-off-by: Zhipeng Lu <alexious@zju.edu.cn>
---
 drivers/net/ethernet/marvell/octeontx2/af/rvu_devlink.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/marvell/octeontx2/af/rvu_devlink.c b/drivers/net/ethernet/marvell/octeontx2/af/rvu_devlink.c
index 41df5ac23f92..058f75dc4c8a 100644
--- a/drivers/net/ethernet/marvell/octeontx2/af/rvu_devlink.c
+++ b/drivers/net/ethernet/marvell/octeontx2/af/rvu_devlink.c
@@ -1285,7 +1285,7 @@ static int rvu_npa_register_reporters(struct rvu_devlink *rvu_dl)
 
 	rvu_dl->devlink_wq = create_workqueue("rvu_devlink_wq");
 	if (!rvu_dl->devlink_wq)
-		goto err;
+		return -ENOMEM;
 
 	INIT_WORK(&rvu_reporters->intr_work, rvu_npa_intr_work);
 	INIT_WORK(&rvu_reporters->err_work, rvu_npa_err_work);
@@ -1293,9 +1293,6 @@ static int rvu_npa_register_reporters(struct rvu_devlink *rvu_dl)
 	INIT_WORK(&rvu_reporters->ras_work, rvu_npa_ras_work);
 
 	return 0;
-err:
-	rvu_npa_health_reporters_destroy(rvu_dl);
-	return -ENOMEM;
 }
 
 static int rvu_npa_health_reporters_create(struct rvu_devlink *rvu_dl)
-- 
2.34.1