From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
To: Biju Das <biju.das@bp.renesas.com>,
Geert Uytterhoeven <geert+renesas@glider.be>,
Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Simon Horman <horms@verge.net.au>,
Chris Paterson <Chris.Paterson2@renesas.com>,
Fabrizio Castro <fabrizio.castro@bp.renesas.com>,
Alessandro Zummo <a.zummo@towertech.it>,
linux-rtc@vger.kernel.org, linux-renesas-soc@vger.kernel.org
Subject: Re: [PATCH v4 1/5] nvmem: check invalid number of bytes in nvmem_device_{read,write}
Date: Mon, 10 Dec 2018 12:37:06 +0000 [thread overview]
Message-ID: <3c09d148-7102-1ee5-770a-009e40de6168@linaro.org> (raw)
In-Reply-To: <1544182066-31528-2-git-send-email-biju.das@bp.renesas.com>
Thanks for the patch.
On 07/12/18 11:27, Biju Das wrote:
> Add check in nvmem_device_{read,write}()to ensure that nvmem core never
> passes an invalid number of bytes.
>
> Signed-off-by: Biju Das <biju.das@bp.renesas.com>
> ---
> V3-->V4
> * New patch.
> ---
> drivers/nvmem/core.c | 26 +++++++++++++++++++++++++-
> 1 file changed, 25 insertions(+), 1 deletion(-)
>
Its better to move checks from
bin_attr_nvmem_read()/bin_attr_nvmem_write() into nvmem_reg_read() and
nvmem_reg_write(), so its easy to maintain, rather than adding them to
each function.
> diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
> index d9fd110..db7de33 100644
> --- a/drivers/nvmem/core.c
> +++ b/drivers/nvmem/core.c
> @@ -1433,10 +1433,21 @@ int nvmem_device_read(struct nvmem_device *nvmem,
> size_t bytes, void *buf)
> {
> int rc;
> + size_t new_bytes;
>
> if (!nvmem)
> return -EINVAL;
>
> + /* Stop the user from reading */
> + if ((offset >= nvmem->size) || (bytes == 0))
> + return 0;
> +
> + if (unlikely(check_add_overflow(bytes, offset, &new_bytes)))
> + return -EOVERFLOW;
> +
> + if (new_bytes > nvmem->size)
> + bytes = nvmem->size - offset;
> +
> rc = nvmem_reg_read(nvmem, offset, buf, bytes);
>
> if (rc)
> @@ -1461,16 +1472,29 @@ int nvmem_device_write(struct nvmem_device *nvmem,
> size_t bytes, void *buf)
> {
> int rc;
> + size_t new_bytes;
>
> if (!nvmem)
> return -EINVAL;
>
> + /* Stop the user from writing */
> + if (offset >= nvmem->size)
> + return -ENOSPC;
> +
> + if (bytes == 0)
> + return 0;
> +
> + if (unlikely(check_add_overflow(bytes, offset, &new_bytes)))
> + return -EOVERFLOW;
> +
> + if (new_bytes > nvmem->size)
> + bytes = nvmem->size - offset;
> +
> rc = nvmem_reg_write(nvmem, offset, buf, bytes);
>
> if (rc)
> return rc;
>
> -
Unrelated change!
--srini
> return bytes;
> }
> EXPORT_SYMBOL_GPL(nvmem_device_write);
>
next prev parent reply other threads:[~2018-12-10 12:37 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-07 11:27 [PATCH v4 0/5] Add NXP pcf85263 real-time clock support Biju Das
2018-12-07 11:27 ` [PATCH v4 1/5] nvmem: check invalid number of bytes in nvmem_device_{read,write} Biju Das
2018-12-10 12:37 ` Srinivas Kandagatla [this message]
2018-12-10 12:45 ` Biju Das
2018-12-10 12:55 ` Srinivas Kandagatla
2018-12-10 15:35 ` Biju Das
2018-12-07 11:27 ` [PATCH v4 2/5] dt-bindings: rtc: pcf85363: Document pcf85263 real-time clock Biju Das
2018-12-07 23:19 ` Rob Herring
2018-12-10 12:16 ` Simon Horman
2018-12-11 11:15 ` Alexandre Belloni
2018-12-07 11:27 ` [PATCH v4 3/5] rtc: pcf85363: Add support for NXP pcf85263 rtc Biju Das
2018-12-11 11:15 ` Alexandre Belloni
2018-12-07 11:27 ` [PATCH v4 4/5] ARM: shmobile: Enable NXP pcf85363 rtc in shmobile_defconfig Biju Das
2018-12-10 12:13 ` Simon Horman
2018-12-10 12:35 ` Biju Das
2018-12-10 13:22 ` Simon Horman
2018-12-07 11:27 ` [PATCH v4 5/5] ARM: dts: iwg23s-sbc: Enable RTC Biju Das
2018-12-10 12:15 ` Simon Horman
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