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From:   Wen Yang <wenyang@linux.alibaba.com>
To:     Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc:     zhiche.yy@alibaba-inc.com, xlpang@linux.alibaba.com,
        Wen Yang <wenyang@linux.alibaba.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel@vger.kernel.org
Subject: [PATCH] intel_th: avoid double free in error flow
Date:   Wed, 20 Nov 2019 01:34:47 +0800
Message-Id: <20191119173447.2454-1-wenyang@linux.alibaba.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

There is a possible double free issue in intel_th_subdevice_alloc:

651         err = intel_th_device_add_resources(thdev, res, subdev->nres);
652         if (err) {
653                 put_device(&thdev->dev);
654                 goto fail_put_device;     ---> freed
655         }
...
687 fail_put_device:
688         put_device(&thdev->dev);          ---> double freed
689

This patch fix it by removing the unnecessary put_device().

Fixes: a753bfcfdb1f ("intel_th: Make the switch allocate its subdevices")
Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org
---
 drivers/hwtracing/intel_th/core.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c
index d5c1821..98d195c 100644
--- a/drivers/hwtracing/intel_th/core.c
+++ b/drivers/hwtracing/intel_th/core.c
@@ -649,10 +649,8 @@ static inline void intel_th_request_hub_module_flush(struct intel_th *th)
 	}
 
 	err = intel_th_device_add_resources(thdev, res, subdev->nres);
-	if (err) {
-		put_device(&thdev->dev);
+	if (err)
 		goto fail_put_device;
-	}
 
 	if (subdev->type == INTEL_TH_OUTPUT) {
 		if (subdev->mknode)
-- 
1.8.3.1