From: Greg KH <gregkh@linuxfoundation.org>
To: Zhou Qingyang <zhou1615@umn.edu>
Cc: kjlu@umn.edu, Damien Le Moal <damien.lemoal@opensource.wdc.com>,
Alexander Shiyan <shc_work@mail.ru>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
Jens Axboe <axboe@kernel.dk>,
linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ata: pata_platform: Fix a NULL pointer dereference in __pata_platform_probe()
Date: Fri, 28 Jan 2022 11:11:59 +0100 [thread overview]
Message-ID: <YfPBb4gHDkr76xPT@kroah.com> (raw)
In-Reply-To: <20220124164525.53068-1-zhou1615@umn.edu>
On Tue, Jan 25, 2022 at 12:45:25AM +0800, Zhou Qingyang wrote:
> In __pata_platform_probe(), devm_kzalloc() is assigned to ap->ops and
> there is a dereference of it right after that, which could introduce a
> NULL pointer dereference bug.
>
> Fix this by adding a NULL check of ap->ops.
>
> This bug was found by a static analyzer.
>
> Builds with 'make allyesconfig' show no new warnings,
> and our static analyzer no longer warns about this code.
>
> Fixes: f3d5e4f18dba ("ata: pata_of_platform: Allow to use 16-bit wide data transfer")
> Signed-off-by: Zhou Qingyang <zhou1615@umn.edu>
> ---
As stated in the past, please do not make contributions to the Linux
kernel until umn.edu has properly resolved its development issues.
> The analysis employs differential checking to identify inconsistent
> security operations (e.g., checks or kfrees) between two code paths
> and confirms that the inconsistent operations are not recovered in the
> current function or the callers, so they constitute bugs.
>
> Note that, as a bug found by static analysis, it can be a false
> positive or hard to trigger. Multiple researchers have cross-reviewed
> the bug.
>
> drivers/ata/pata_platform.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/ata/pata_platform.c b/drivers/ata/pata_platform.c
> index 028329428b75..021ef9cbcbc1 100644
> --- a/drivers/ata/pata_platform.c
> +++ b/drivers/ata/pata_platform.c
> @@ -128,6 +128,8 @@ int __pata_platform_probe(struct device *dev, struct resource *io_res,
> ap = host->ports[0];
>
> ap->ops = devm_kzalloc(dev, sizeof(*ap->ops), GFP_KERNEL);
> + if (ap->ops)
> + return -ENOMEM;
This change seems to leak memory. Damien, please revert it.
thanks,
greg k-h
next prev parent reply other threads:[~2022-01-28 10:12 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-24 16:45 [PATCH] ata: pata_platform: Fix a NULL pointer dereference in __pata_platform_probe() Zhou Qingyang
2022-01-25 9:46 ` Sergey Shtylyov
2022-01-27 2:15 ` Damien Le Moal
2022-01-27 9:37 ` Sergey Shtylyov
2022-01-27 1:54 ` Damien Le Moal
2022-01-28 10:11 ` Greg KH [this message]
2022-01-28 11:50 ` Damien Le Moal
2022-01-28 15:57 ` Greg KH
2022-01-29 0:12 ` Damien Le Moal
2022-01-29 7:06 ` Greg KH
2022-01-31 0:11 ` Damien Le Moal
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