[PATCH 6.12 021/466] ptp: Add error handling for adjfine callback in ptp_clock_adjtime

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ajay Kaher <ajay.kaher@broadcom.com>

[ Upstream commit 98337d7c87577ded71114f6976edb70a163e27bc ]

ptp_clock_adjtime sets ptp->dialed_frequency even when adjfine
callback returns an error. This causes subsequent reads to return
an incorrect value.

Fix this by adding error check before ptp->dialed_frequency is set.

Fixes: 39a8cbd9ca05 ("ptp: remember the adjusted frequency")
Signed-off-by: Ajay Kaher <ajay.kaher@broadcom.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Link: https://patch.msgid.link/20241125105954.1509971-1-ajay.kaher@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/ptp/ptp_clock.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index c56cd0f63909a..77a36e7bddd54 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -150,7 +150,8 @@ static int ptp_clock_adjtime(struct posix_clock *pc, struct __kernel_timex *tx)
 		if (ppb > ops->max_adj || ppb < -ops->max_adj)
 			return -ERANGE;
 		err = ops->adjfine(ops, tx->freq);
-		ptp->dialed_frequency = tx->freq;
+		if (!err)
+			ptp->dialed_frequency = tx->freq;
 	} else if (tx->modes & ADJ_OFFSET) {
 		if (ops->adjphase) {
 			s32 max_phase_adj = ops->getmaxphase(ops);
-- 
2.43.0