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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Atul Gopinathan <atulgopinathan@gmail.com>,
        Jens Axboe <axboe@kernel.dk>, Peter Rosin <peda@axentia.se>,
        stable <stable@vger.kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: [PATCH 27/69] cdrom: gdrom: deallocate struct gdrom_unit fields in remove_gdrom
Date:   Mon,  3 May 2021 13:56:54 +0200
Message-Id: <20210503115736.2104747-28-gregkh@linuxfoundation.org>
In-Reply-To: <20210503115736.2104747-1-gregkh@linuxfoundation.org>
References: <20210503115736.2104747-1-gregkh@linuxfoundation.org>
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From: Atul Gopinathan <atulgopinathan@gmail.com>

The fields, "toc" and "cd_info", of "struct gdrom_unit gd" are allocated
in "probe_gdrom()". Prevent a memory leak by making sure "gd.cd_info" is
deallocated in the "remove_gdrom()" function.

Also prevent double free of the field "gd.toc" by moving it from the
module's exit function to "remove_gdrom()". This is because, in
"probe_gdrom()", the function makes sure to deallocate "gd.toc" in case
of any errors, so the exit function invoked later would again free
"gd.toc".

The patch also maintains consistency by deallocating the above mentioned
fields in "remove_gdrom()" along with another memory allocated field
"gd.disk".

Suggested-by: Jens Axboe <axboe@kernel.dk>
Cc: Peter Rosin <peda@axentia.se>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Atul Gopinathan <atulgopinathan@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/cdrom/gdrom.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/cdrom/gdrom.c b/drivers/cdrom/gdrom.c
index 7f681320c7d3..6c4f6139f853 100644
--- a/drivers/cdrom/gdrom.c
+++ b/drivers/cdrom/gdrom.c
@@ -830,6 +830,8 @@ static int remove_gdrom(struct platform_device *devptr)
 	if (gdrom_major)
 		unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
 	unregister_cdrom(gd.cd_info);
+	kfree(gd.cd_info);
+	kfree(gd.toc);
 
 	return 0;
 }
@@ -861,7 +863,6 @@ static void __exit exit_gdrom(void)
 {
 	platform_device_unregister(pd);
 	platform_driver_unregister(&gdrom_driver);
-	kfree(gd.toc);
 }
 
 module_init(init_gdrom);
-- 
2.31.1