[PATCH] ptp: Add error handling for adjfine callback in ptp_clock_adjtime

[PATCH] ptp: Add error handling for adjfine callback in ptp_clock_adjtime

[Ajay Kaher]

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>
---
 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 c56cd0f..77a36e7 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);
-- 
2.39.4

Re: [PATCH] ptp: Add error handling for adjfine callback in ptp_clock_adjtime

[Richard Cochran]

On Mon, Nov 25, 2024 at 10:59:54AM +0000, Ajay Kaher wrote:
> 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>

Re: [PATCH] ptp: Add error handling for adjfine callback in ptp_clock_adjtime

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Mon, 25 Nov 2024 10:59:54 +0000 you wrote:
> 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>
> 
> [...]

Here is the summary with links:
  - ptp: Add error handling for adjfine callback in ptp_clock_adjtime
    https://git.kernel.org/netdev/net/c/98337d7c8757

You are awesome, thank you!
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