6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
commit fd53aa40e65f518453115b6f56183b0c201db26b upstream.
The ioctl and sysfs handlers unconditionally call the ->enable callback.
Not all drivers implement that callback, leading to NULL dereferences.
Example of affected drivers: ptp_s390.c, ptp_vclock.c and ptp_mock.c.
Instead use a dummy callback if no better was specified by the driver.
Fixes: d94ba80ebbea ("ptp: Added a brand new class driver for ptp clocks.")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
Acked-by: Richard Cochran <richardcochran@xxxxxxxxx>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@xxxxxxxxxxxxxxx>
Link: https://patch.msgid.link/20250123-ptp-enable-v1-1-b015834d3a47@xxxxxxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/ptp/ptp_clock.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -217,6 +217,11 @@ static int ptp_getcycles64(struct ptp_cl
return info->gettime64(info, ts);
}
+static int ptp_enable(struct ptp_clock_info *ptp, struct ptp_clock_request *request, int on)
+{
+ return -EOPNOTSUPP;
+}
+
static void ptp_aux_kworker(struct kthread_work *work)
{
struct ptp_clock *ptp = container_of(work, struct ptp_clock,
@@ -294,6 +299,9 @@ struct ptp_clock *ptp_clock_register(str
ptp->info->getcrosscycles = ptp->info->getcrosststamp;
}
+ if (!ptp->info->enable)
+ ptp->info->enable = ptp_enable;
+
if (ptp->info->do_aux_work) {
kthread_init_delayed_work(&ptp->aux_work, ptp_aux_kworker);
ptp->kworker = kthread_create_worker(0, "ptp%d", ptp->index);
