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From: Dan Carpenter <dan.carpenter@oracle.com>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>,
	Linux Media Mailing List <linux-media@vger.kernel.org>,
	royale@zerezo.com, USB <linux-usb@vger.kernel.org>,
	syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
	syzbot+b4d54814b339b5c6bbd4@syzkaller.appspotmail.com
Subject: Re: [RFT][PATCH v1] media: zr364xx: Fix memory leak in ->probe()
Date: Tue, 5 Jan 2021 17:00:45 +0300	[thread overview]
Message-ID: <20210105140045.GF2809@kadam> (raw)
In-Reply-To: <20201230211918.63508-1-andriy.shevchenko@linux.intel.com>

On Wed, Dec 30, 2020 at 11:19:18PM +0200, Andy Shevchenko wrote:
> When ->probe() fails in some cases it may not free resources.
> Replace few separated calls by v4l2_device_put() to clean up
> everything.
> 

The clean up everything style of error handling is always buggy.

For example, in this case, all the early error paths will now crash
instead of leaking.  The __videobuf_free() function will Oops when it
dereferences "q->int_ops->magic".

	MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);

The "q->int_ops" pointer is set in videobuf_queue_vmalloc_init().  There
are probably other bugs as well.  It's almost impossible to audit this
style of error handling either for completeness or for crashyness.

regards,
dan carpenter


  parent reply	other threads:[~2021-01-05 14:01 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-30 21:19 [RFT][PATCH v1] media: zr364xx: Fix memory leak in ->probe() Andy Shevchenko
2020-12-31  1:53 ` Ezequiel Garcia
2020-12-31  1:53   ` syzbot
2021-01-05 14:00 ` Dan Carpenter [this message]
2021-01-05 14:37   ` Andy Shevchenko
2021-01-05 16:04     ` Dan Carpenter

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