5.4-stable review patch. If anyone has any objections, please let me know.
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From: Thomas Weißschuh linux@weissschuh.net
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@vger.kernel.org Signed-off-by: Thomas Weißschuh linux@weissschuh.net Acked-by: Richard Cochran richardcochran@gmail.com Reviewed-by: Michal Swiatkowski michal.swiatkowski@linux.intel.com Link: https://patch.msgid.link/20250123-ptp-enable-v1-1-b015834d3a47@weissschuh.ne... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/ptp/ptp_clock.c | 8 ++++++++ 1 file changed, 8 insertions(+)
--- a/drivers/ptp/ptp_clock.c +++ b/drivers/ptp/ptp_clock.c @@ -178,6 +178,11 @@ static void ptp_clock_release(struct dev kfree(ptp); }
+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, @@ -223,6 +228,9 @@ struct ptp_clock *ptp_clock_register(str mutex_init(&ptp->pincfg_mux); init_waitqueue_head(&ptp->tsev_wq);
+ 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);