From: Miquel Raynal <miquel.raynal@bootlin.com>
To: William Zhang <william.zhang@broadcom.com>
Cc: Broadcom Kernel List <bcm-kernel-feedback-list@broadcom.com>,
Linux MTD List <linux-mtd@lists.infradead.org>,
f.fainelli@gmail.com, rafal@milecki.pl, kursad.oney@broadcom.com,
joel.peshkin@broadcom.com, computersforpeace@gmail.com,
anand.gore@broadcom.com, dregan@mail.com,
kamal.dasu@broadcom.com, tomer.yacoby@broadcom.com,
dan.beygelman@broadcom.com,
Florian Fainelli <florian.fainelli@broadcom.com>,
linux-kernel@vger.kernel.org,
Vignesh Raghavendra <vigneshr@ti.com>,
Richard Weinberger <richard@nod.at>,
Kamal Dasu <kdasu.kdev@gmail.com>
Subject: Re: [PATCH 04/12] mtd: rawnand: brcmnand: Fix potential out-of-bounds access in oob write
Date: Wed, 7 Jun 2023 10:09:02 +0200 [thread overview]
Message-ID: <20230607100902.4df2bc27@xps-13> (raw)
In-Reply-To: <20230606231252.94838-5-william.zhang@broadcom.com>
Hi William,
william.zhang@broadcom.com wrote on Tue, 6 Jun 2023 16:12:44 -0700:
> When the oob buffer length is not in multiple of words, the oob write
> function does out-of-bounds read on the oob source buffer at the last
> iteration. Fix that by always checking length limit on the oob buffer
> read and fill with 0xff when reaching the end of the buffer to the oob
> registers.
>
> Fixes: 27c5b17cd1b1 ("mtd: nand: add NAND driver "library" for Broadcom STB NAND controller")
> Signed-off-by: William Zhang <william.zhang@broadcom.com>
> Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
> ---
>
> drivers/mtd/nand/raw/brcmnand/brcmnand.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> index 20832857c4aa..d920e88c7f5b 100644
> --- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> +++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> @@ -1486,10 +1486,10 @@ static int write_oob_to_regs(struct brcmnand_controller *ctrl, int i,
>
> for (j = 0; j < tbytes; j += 4)
> oob_reg_write(ctrl, j,
> - (oob[j + 0] << 24) |
> - (oob[j + 1] << 16) |
> - (oob[j + 2] << 8) |
> - (oob[j + 3] << 0));
> + (((j < tbytes) ? oob[j] : 0xff) << 24) |
> + (((j + 1 < tbytes) ? oob[j + 1] : 0xff) << 16) |
> + (((j + 2 < tbytes) ? oob[j + 2] : 0xff) << 8) |
> + ((j + 3 < tbytes) ? oob[j + 3] : 0xff));
This is a lot of additional operations which most of the time are not
relevant. I would instead got for one less iteration in the for loop
when there is unaligned data, and then dedicated if/else to fill the
missing bytes.
> return tbytes;
> }
>
Thanks,
Miquèl
next prev parent reply other threads:[~2023-06-07 8:09 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-06 23:12 [PATCH 00/12] mtd: rawnand: brcmnand: driver and doc updates William Zhang
2023-06-06 23:12 ` [PATCH 01/12] mtd: rawnand: brcmnand: Fix ECC level field setting for v7.2 controller William Zhang
2023-06-07 8:06 ` Miquel Raynal
2023-06-06 23:12 ` [PATCH 02/12] mtd: rawnand: brcmnand: Fix potential false time out warning William Zhang
2023-06-06 23:12 ` [PATCH 03/12] mtd: rawnand: brcmnand: Fix crash during the panic_write William Zhang
2023-06-06 23:12 ` [PATCH 04/12] mtd: rawnand: brcmnand: Fix potential out-of-bounds access in oob write William Zhang
2023-06-07 8:09 ` Miquel Raynal [this message]
2023-06-06 23:12 ` [PATCH 05/12] dt-bindings: mtd: brcmnand: Updates for bcmbca SoCs William Zhang
2023-06-07 8:14 ` Miquel Raynal
2023-06-07 20:01 ` William Zhang
2023-06-09 8:58 ` Miquel Raynal
2023-06-09 19:05 ` William Zhang
2023-06-12 17:43 ` Miquel Raynal
2023-06-14 22:46 ` Rob Herring
2023-06-15 0:40 ` William Zhang
2023-06-14 22:43 ` Rob Herring
2023-06-15 0:28 ` William Zhang
2023-06-06 23:12 ` [PATCH 06/12] ARM: dts: broadcom: bcmbca: Add NAND controller node William Zhang
2023-06-06 23:12 ` [PATCH 07/12] arm64: " William Zhang
2023-06-06 23:12 ` [PATCH 08/12] mtd: rawnand: brcmnand: Rename bcm63138 nand driver William Zhang
2023-06-06 23:12 ` [PATCH 09/12] mtd: rawnand: brcmnand: Add new compatible string William Zhang
2023-06-06 23:12 ` [PATCH 10/12] mtd: rawnand: brcmnand: Add BCMBCA read data bus interface William Zhang
2023-06-07 8:20 ` Miquel Raynal
2023-06-07 20:12 ` William Zhang
2023-06-08 6:15 ` Miquel Raynal
2023-06-08 19:04 ` William Zhang
2023-06-07 8:22 ` Miquel Raynal
2023-06-07 20:24 ` William Zhang
2023-06-08 6:18 ` Miquel Raynal
2023-06-08 19:10 ` William Zhang
2023-06-09 8:35 ` Miquel Raynal
2023-06-09 19:16 ` William Zhang
2023-06-12 17:49 ` Miquel Raynal
2023-06-12 17:53 ` Miquel Raynal
2023-06-12 19:18 ` William Zhang
2023-06-13 6:42 ` Miquel Raynal
2023-06-14 0:00 ` William Zhang
2023-06-14 6:22 ` Miquel Raynal
2023-06-14 23:52 ` William Zhang
2023-06-12 19:03 ` William Zhang
2023-06-11 9:54 ` kernel test robot
2023-06-06 23:12 ` [PATCH 11/12] mtd: rawnand: brcmnand: Add support for getting ecc setting from strap William Zhang
2023-06-07 8:25 ` Miquel Raynal
2023-06-06 23:12 ` [PATCH 12/12] mtd: rawnand: brcmnand: Support write protection setting from dts William Zhang
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