Received-SPF: pass (google.com: domain of linux-kernel+bounces-89683-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1;
From: hyper <hyperlyzcs@gmail.com>
To: shannon.nelson@amd.com,
	brett.creeley@amd.com,
	davem@davemloft.net,
	edumazet@google.com,
	kuba@kernel.org,
	pabeni@redhat.com
Cc: netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	jitxie@tencent.com,
	huntazhang@tencent.com,
	hyper <hyperlyzcs@gmail.com>
Subject: [PATCH net V2] net: pds_core: Fix possible double free in error handling path
Date: Sun,  3 Mar 2024 16:49:54 +0800
Message-Id: <20240303084954.14498-1-hyperlyzcs@gmail.com>
In-Reply-To: <333dca5e-fae7-4684-afa8-10b8fdd48bf6@amd.com>
References: <333dca5e-fae7-4684-afa8-10b8fdd48bf6@amd.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

When auxiliary_device_add() returns error and then calls
auxiliary_device_uninit(), Callback function pdsc_auxbus_dev_release
calls kfree(padev) to free memory. We shouldn't call kfree(padev)
again in the error handling path.

Fix this by cleaning up the redundant kfree() and putting
the error handling back to where the errors happened.

Fixes: 4569cce43bc6 ("pds_core: add auxiliary_bus devices")
Signed-off-by: hyper <hyperlyzcs@gmail.com>
---
 drivers/net/ethernet/amd/pds_core/auxbus.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/amd/pds_core/auxbus.c b/drivers/net/ethernet/amd/pds_core/auxbus.c
index 11c23a7f3172..fd1a5149c003 100644
--- a/drivers/net/ethernet/amd/pds_core/auxbus.c
+++ b/drivers/net/ethernet/amd/pds_core/auxbus.c
@@ -160,23 +160,19 @@ static struct pds_auxiliary_dev *pdsc_auxbus_dev_register(struct pdsc *cf,
 	if (err < 0) {
 		dev_warn(cf->dev, "auxiliary_device_init of %s failed: %pe\n",
 			 name, ERR_PTR(err));
-		goto err_out;
+		kfree(padev);
+		return ERR_PTR(err);
 	}
 
 	err = auxiliary_device_add(aux_dev);
 	if (err) {
 		dev_warn(cf->dev, "auxiliary_device_add of %s failed: %pe\n",
 			 name, ERR_PTR(err));
-		goto err_out_uninit;
+		auxiliary_device_uninit(aux_dev);
+		return ERR_PTR(err);
 	}
 
 	return padev;
-
-err_out_uninit:
-	auxiliary_device_uninit(aux_dev);
-err_out:
-	kfree(padev);
-	return ERR_PTR(err);
 }
 
 int pdsc_auxbus_dev_del(struct pdsc *cf, struct pdsc *pf)
-- 
2.36.1