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From: Su Hui <suhui@nfschina.com>
To: marcel@holtmann.org,
	luiz.dentz@gmail.com,
	nathan@kernel.org,
	ndesaulniers@google.com,
	morbo@google.com,
	justinstitt@google.com
Cc: Su Hui <suhui@nfschina.com>,
	kiran.k@intel.com,
	seema.sreemantha@intel.com,
	linux-bluetooth@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	llvm@lists.linux.dev,
	kernel-janitors@vger.kernel.org
Subject: [PATCH 2/2]  Bluetooth: btintel: fix use after free problem in btintel_ppag_callback()
Date: Mon, 20 May 2024 10:16:27 +0800
Message-Id: <20240520021625.110430-2-suhui@nfschina.com>
In-Reply-To: <20240520021625.110430-1-suhui@nfschina.com>
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Clang static checker(scan-build) warning:
drivers/bluetooth/btintel.c:1369:8: Use of memory after it is freed.

'p' is equal to 'buffer.pointer', using of 'p->type' after releasing
'buffer.pointer' causes this use after free problem.
Change the order of releasing buffer.pointer to fix this problem.

Fixes: c585a92b2f9c ("Bluetooth: btintel: Set Per Platform Antenna Gain(PPAG)")
Signed-off-by: Su Hui <suhui@nfschina.com>
---
 drivers/bluetooth/btintel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/bluetooth/btintel.c b/drivers/bluetooth/btintel.c
index f1c101dc0c28..d94a8ccd1428 100644
--- a/drivers/bluetooth/btintel.c
+++ b/drivers/bluetooth/btintel.c
@@ -1364,9 +1364,9 @@ static acpi_status btintel_ppag_callback(acpi_handle handle, u32 lvl, void *data
 	ppag = (struct btintel_ppag *)data;
 
 	if (p->type != ACPI_TYPE_PACKAGE || p->package.count != 2) {
-		kfree(buffer.pointer);
 		bt_dev_warn(hdev, "PPAG-BT: Invalid object type: %d or package count: %d",
 			    p->type, p->package.count);
+		kfree(buffer.pointer);
 		ppag->status = AE_ERROR;
 		return AE_ERROR;
 	}
-- 
2.30.2