From:   "Stein, Alexander" <Alexander.Stein@tq-group.com>
To:     "linux-mtd@lists.infradead.org" <linux-mtd@lists.infradead.org>,
        "Tudor.Ambarus@microchip.com" <Tudor.Ambarus@microchip.com>
CC:     "michael@walle.cc" <michael@walle.cc>,
        "p.yadav@ti.com" <p.yadav@ti.com>,
        "vigneshr@ti.com" <vigneshr@ti.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] mtd: spi-nor: Fix shift-out-of-bounds
Thread-Topic: [PATCH 1/2] mtd: spi-nor: Fix shift-out-of-bounds
Thread-Index: AQHYOQodYTda3weuU0+yf380GWE6Ea6t9KqA
Date:   Mon, 23 Jan 2023 15:02:45 +0000
Message-ID: <5642351.DvuYhMxLoT@steina-w>
References: <20211106075616.95401-1-tudor.ambarus@microchip.com>
 <5550605.DvuYhMxLoT@steina-w>
 <b8d01f36-663a-928a-6dbe-64952b5bd8d0@microchip.com>
In-Reply-To: <b8d01f36-663a-928a-6dbe-64952b5bd8d0@microchip.com>
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Hi Tudor,=0A=
=0A=
Am Mittwoch, 16. M=E4rz 2022, 08:47:40 CET schrieb Tudor.Ambarus@microchip.=
com:=0A=
> On 3/16/22 09:39, Alexander Stein wrote:=0A=
> =0A=
> > [You don't often get email from alexander.stein@tq-group.com. Learn why=
=0A=
> > this is important at http://aka.ms/LearnAboutSenderIdentification.]=0A=
 =0A=
> > EXTERNAL EMAIL: Do not click links or open attachments unless you know =
the=0A=
> > content is safe=0A=
 =0A=
> > Hello,=0A=
> =0A=
> =0A=
> hi,=0A=
> =0A=
> =0A=
> > =0A=
> > Am Samstag, 6. November 2021, 08:56:15 CET schrieb Tudor Ambarus:=0A=
> > =0A=
> >> When paring SFDP we may choose to mask out an erase type, passing=0A=
> >> an erase size of zero to spi_nor_set_erase_type().=0A=
> >> Fix shift-out-of-bounds and just clear the erase params when=0A=
> >> passing zero for erase size.=0A=
> >> While here avoid a superfluous dereference and use 'size' directly.=0A=
> >>=0A=
> >>=0A=
> >>=0A=
> >> UBSAN: shift-out-of-bounds in drivers/mtd/spi-nor/core.c:2237:24=0A=
> >> shift exponent 4294967295 is too large for 32-bit type 'int'=0A=
> >>=0A=
> >>=0A=
> >>=0A=
> >> Fixes: 5390a8df769e ("mtd: spi-nor: add support to non-uniform SFDP SP=
I=0A=
> >> NOR=0A=
 flash memories") Reported-by: Alexander Stein=0A=
> >> <Alexander.Stein@tq-group.com>=0A=
> >> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>=0A=
> >> ---=0A=
> >> =0A=
> >>  drivers/mtd/spi-nor/core.c | 9 +++++++--=0A=
> >>  1 file changed, 7 insertions(+), 2 deletions(-)=0A=
> >>=0A=
> >>=0A=
> >>=0A=
> >> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c=
=0A=
> >> index 3d97c189c332..a1b5d5432f41 100644=0A=
> >> --- a/drivers/mtd/spi-nor/core.c=0A=
> >> +++ b/drivers/mtd/spi-nor/core.c=0A=
> >> @@ -2230,8 +2230,13 @@ void spi_nor_set_erase_type(struct=0A=
> >> spi_nor_erase_type=0A=
 *erase, u32 size, erase->size =3D size;=0A=
> >> =0A=
> >>       erase->opcode =3D opcode;=0A=
> >>       /* JEDEC JESD216B Standard imposes erase sizes to be power of 2.=
=0A=
> >>       */=0A=
> >> =0A=
> >> -     erase->size_shift =3D ffs(erase->size) - 1;=0A=
> >> -     erase->size_mask =3D (1 << erase->size_shift) - 1;=0A=
> >> +     if (size) {=0A=
> >> +             erase->size_shift =3D ffs(size) - 1;=0A=
> >> +             erase->size_mask =3D (1 << erase->size_shift) - 1;=0A=
> >> +     } else {=0A=
> >> +             erase->size_shift =3D 0;=0A=
> >> +             erase->size_mask =3D 0;=0A=
> >> +     }=0A=
> >> =0A=
> >>  }=0A=
> >>=0A=
> >>=0A=
> >>=0A=
> >>  /**=0A=
> > =0A=
> > =0A=
> > What is the status of this patch? It is not applied up until now, no? H=
as=0A=
> > it=0A=
 been superseeded?=0A=
> > =0A=
> =0A=
> =0A=
> I think it's marked with "changes requested". I'm going to send a v2.=0A=
=0A=
Is there a v2 somewhere?=0A=
=0A=
Best regards,=0A=
Alexander=0A=