The following commit has been merged into the timers/urgent branch of tip: Commit-ID: 299130166e70124956c865a66a3669a61db1c212 Gitweb: https://git.kernel.org/tip/299130166e70124956c865a66a3669a61db1c212 Author: Marcelo Dalmas <marcelo.dalmas@xxxxxx> AuthorDate: Mon, 25 Nov 2024 12:16:09 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitterDate: Wed, 27 Nov 2024 15:18:45 +01:00 ntp: Remove invalid cast in time offset math Due to an unsigned cast, adjtimex() returns the wrong offest when using ADJ_MICRO and the offset is negative. In this case a small negative offset returns approximately 4.29 seconds (~ 2^32/1000 milliseconds) due to the unsigned cast of the negative offset. Remove the cast and restore the signed division to cure that issue. Fixes: ead25417f82e ("timex: use __kernel_timex internally") Signed-off-by: Marcelo Dalmas <marcelo.dalmas@xxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Link: https://lore.kernel.org/all/SJ0P101MB03687BF7D5A10FD3C49C51E5F42E2@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx --- kernel/time/ntp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index b550ebe..02e7fe6 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -798,7 +798,7 @@ int __do_adjtimex(struct __kernel_timex *txc, const struct timespec64 *ts, txc->offset = shift_right(ntpdata->time_offset * NTP_INTERVAL_FREQ, NTP_SCALE_SHIFT); if (!(ntpdata->time_status & STA_NANO)) - txc->offset = (u32)txc->offset / NSEC_PER_USEC; + txc->offset /= NSEC_PER_USEC; } result = ntpdata->time_state;
