[PATCH] firewire: cdev: Check return value in ioctl_get_cycle_timer()

[PATCH] firewire: cdev: Check return value in ioctl_get_cycle_timer()

[Sreeraj S Kurup]

ioctl_get_cycle_timer() ignores the return value of
ioctl_get_cycle_timer2(). If the latter fails, the output fields
may remain uninitialized, causing the caller to use uninitialized
data when calculating local_time and assigning cycle_timer.

Check the return value and propagate the error to the caller.

Signed-off-by: Sreeraj S Kurup <sreekuttan2156239@gmail.com>
---
 drivers/firewire/core-cdev.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index 87efd65e6b00..76606c37d212 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -1316,9 +1316,12 @@ static int ioctl_get_cycle_timer(struct client *client, union ioctl_arg *arg)
 {
 	struct fw_cdev_get_cycle_timer *a = &arg->get_cycle_timer;
 	struct fw_cdev_get_cycle_timer2 ct2;
+	int ret;
 
 	ct2.clk_id = CLOCK_REALTIME;
-	ioctl_get_cycle_timer2(client, (union ioctl_arg *)&ct2);
+	ret = ioctl_get_cycle_timer2(client, (union ioctl_arg *)&ct2);
+	if (ret < 0)
+		return ret;
 
 	a->local_time = ct2.tv_sec * USEC_PER_SEC + ct2.tv_nsec / NSEC_PER_USEC;
 	a->cycle_timer = ct2.cycle_timer;
-- 
2.55.0

Re: [PATCH] firewire: cdev: Check return value in ioctl_get_cycle_timer()

[Takashi Sakamoto]

Hi,

On Thu, Oct 29, 2026 at 10:15:45AM +0000, Sreeraj S Kurup wrote:
> ioctl_get_cycle_timer() ignores the return value of
> ioctl_get_cycle_timer2(). If the latter fails, the output fields
> may remain uninitialized, causing the caller to use uninitialized
> data when calculating local_time and assigning cycle_timer.
> 
> Check the return value and propagate the error to the caller.
> 
> Signed-off-by: Sreeraj S Kurup <sreekuttan2156239@gmail.com>
> ---
>  drivers/firewire/core-cdev.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)

Applied to for-next branch.

I prefer this submission to the previous ones from other contributors[1].
It's concise, to the point, and easy to read. When using generative AI in
our work, it's especially important to keep the intended recipients in
mind.


[1] https://lore.kernel.org/lkml/20260617023554.2789907-1-michael.bommarito@gmail.com/

Thanks

Takashi Sakamoto

Re: [PATCH] firewire: cdev: Check return value in ioctl_get_cycle_timer()

[Sreeraj S Kurup]

Hi Takashi,

Thanks for applying the patch!

Best regards,
Sreeraj