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Date:   Mon, 10 Aug 2020 18:38:51 +0200
From:   Pavel Machek <pavel@denx.de>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        stable <stable@kernel.org>
Subject: Re: [PATCH 4.19 14/48] mtd: properly check all write ioctls for
 permissions
Message-ID: <20200810163851.GB24408@amd>
References: <20200810151804.199494191@linuxfoundation.org>
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Hi!

> From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>=20
> commit f7e6b19bc76471ba03725fe58e0c218a3d6266c3 upstream.
>=20
> When doing a "write" ioctl call, properly check that we have permissions
> to do so before copying anything from userspace or anything else so we
> can "fail fast".  This includes also covering the MEMWRITE ioctl which
> previously missed checking for this.

> +	/* "safe" commands */
> +	case MEMGETREGIONCOUNT:

I wonder if MEMSETBADBLOCK, MEMLOCK/MEMUNLOCK, BLKPG, OTPLOCK and
MTDFILEMODE should be in the list of "safe" commands? Sounds like they
can do at least as much damage as average MEMWRITE...

Best regards,
								Pavel
--=20
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

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