From c3e735e9f62022354fc63dbf193cb5614188a33b Mon Sep 17 00:00:00 2001 From: Lad Prabhakar Date: Fri, 21 Aug 2026 22:10:20 +0100 Subject: [PATCH] rtc: rzn1: Fix alarm range check truncation on 32-bit systems alarm and farest were declared as unsigned long, but rtc_tm_to_time64() returns time64_t (s64). On 32-bit systems where unsigned long is 32 bits, the assignment silently truncates the upper 32 bits of the timestamp. Fix by declaring alarm and farest as time64_t and replacing time_after() with a direct signed comparison, which is correct for time64_t values that will never realistically overflow. Signed-off-by: Lad Prabhakar Reviewed-by: Geert Uytterhoeven Reviewed-by: Wolfram Sang Tested-by: Wolfram Sang Link: https://patch.msgid.link/20260821211032.13554-6-prabhakar.mahadev-lad.rj@bp.renesas.com Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-rzn1.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/rtc/rtc-rzn1.c b/drivers/rtc/rtc-rzn1.c index d4cba0d415b6..f3268655fd37 100644 --- a/drivers/rtc/rtc-rzn1.c +++ b/drivers/rtc/rtc-rzn1.c @@ -268,7 +268,7 @@ static int rzn1_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct rzn1_rtc *rtc = dev_get_drvdata(dev); struct rtc_time *tm = &alrm->time, tm_now; - unsigned long alarm, farest; + time64_t alarm, farest; int ret; ret = rzn1_rtc_read_time(dev, &tm_now); @@ -278,7 +278,7 @@ static int rzn1_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) /* We cannot set alarms more than one week ahead */ farest = rtc_tm_to_time64(&tm_now) + rtc->rtcdev->alarm_offset_max; alarm = rtc_tm_to_time64(tm); - if (time_after(alarm, farest)) + if (alarm > farest) return -ERANGE; writel(bin2bcd(tm->tm_min), rtc->base + RZN1_RTC_ALM);