linux-kernel - [PATCH 5.10 089/563] tee: fix put order in teedev_close

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Date:   Mon, 24 Jan 2022 19:37:34 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Sumit Garg <sumit.garg@...aro.org>,
        Jens Wiklander <jens.wiklander@...aro.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.10 089/563] tee: fix put order in teedev_close_context()

From: Jens Wiklander <jens.wiklander@...aro.org>

[ Upstream commit f18397ab3ae23e8e43bba9986e66af6d4497f2ad ]

Prior to this patch was teedev_close_context() calling tee_device_put()
before teedev_ctx_put() leading to teedev_ctx_release() accessing
ctx->teedev just after the reference counter was decreased on the
teedev. Fix this by calling teedev_ctx_put() before tee_device_put().

Fixes: 217e0250cccb ("tee: use reference counting for tee_context")
Reviewed-by: Sumit Garg <sumit.garg@...aro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@...aro.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/tee/tee_core.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
index 6ade4a5c48407..dfc239c64ce3c 100644
--- a/drivers/tee/tee_core.c
+++ b/drivers/tee/tee_core.c
@@ -98,8 +98,10 @@ void teedev_ctx_put(struct tee_context *ctx)
 
 static void teedev_close_context(struct tee_context *ctx)
 {
-	tee_device_put(ctx->teedev);
+	struct tee_device *teedev = ctx->teedev;
+
 	teedev_ctx_put(ctx);
+	tee_device_put(teedev);
 }
 
 static int tee_open(struct inode *inode, struct file *filp)
-- 
2.34.1