From: Thomas Weißschuh <linux@weissschuh.net> stable inclusion from stable-v6.6.78 commit 81846070cba17125a866e8023c01d3465b153339 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBPLLG CVE: CVE-2025-21814 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- 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> Signed-off-by: Pu Lehui <pulehui@huawei.com> --- drivers/ptp/ptp_clock.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c index b586da2e3002..6b7e8b7ebcef 100644 --- a/drivers/ptp/ptp_clock.c +++ b/drivers/ptp/ptp_clock.c @@ -189,6 +189,11 @@ static int ptp_getcycles64(struct ptp_clock_info *info, struct timespec64 *ts) 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, @@ -251,6 +256,9 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, 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); -- 2.34.1