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SubjectRe: [RESEND PATCH] rtc: tps65910: add bounds checking
Hi,

On 10/04/2018 15:24:17+0800, SZ Lin (林上智) wrote:
> Since tm->tm_year is the offset relative to 1900, it needs to check for
> positive value to avoid overflow in YEARS_REG register.
>
> The system will hang at the following stage on the next boot when overflow
> has occurred.
>
> [ 2.221192] systemd[1]: Time has been changed
>
> This patch fixes the above hanging issue by adding bounds checking.
>

Did you test linux-next, this should not happen anymore after
https://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux.git/commit/?h=rtc-next&id=b3a5ac42ab18b7d1a8f2f072ca0ee76a3b754a43

> Signed-off-by: Taiyi Wu <taiyity.wu@moxa.com>
> Signed-off-by: SZ Lin (林上智) <sz.lin@moxa.com>
> ---
> drivers/rtc/rtc-tps65910.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/rtc/rtc-tps65910.c b/drivers/rtc/rtc-tps65910.c
> index d0244d7979fc..6be9f7bb0f1b 100644
> --- a/drivers/rtc/rtc-tps65910.c
> +++ b/drivers/rtc/rtc-tps65910.c
> @@ -105,6 +105,12 @@ static int tps65910_rtc_set_time(struct device *dev, struct rtc_time *tm)
> struct tps65910 *tps = dev_get_drvdata(dev->parent);
> int ret;
>
> + if ((tm->tm_year - 100) < 0) {
> + dev_err(dev, "the requested year %d is unsupported\n",
> + 1900 + tm->tm_year);
> + return -EINVAL;
> + }
> +
> rtc_data[0] = bin2bcd(tm->tm_sec);
> rtc_data[1] = bin2bcd(tm->tm_min);
> rtc_data[2] = bin2bcd(tm->tm_hour);
> --
> 2.17.0
>

--
Alexandre Belloni, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com

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