net/sched: sch_taprio: fix undefined behavior in ktime_mono_to_any
1) if q->tk_offset == TK_OFFS_MAX, then get_tcp_tstamp() calls ktime_mono_to_any() with out-of-bound value. 2) if q->tk_offset is changed in taprio_parse_clockid(), taprio_get_time() might also call ktime_mono_to_any() with out-of-bound value as sysbot found: UBSAN: array-index-out-of-bounds in kernel/time/timekeeping.c:908:27 index 3 is out of range for type 'ktime_t *[3]' CPU: 1 PID: 25668 Comm: kworker/u4:0 Not tainted 5.15.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 ubsan_epilogue+0xb/0x5a lib/ubsan.c:151 __ubsan_handle_out_of_bounds.cold+0x62/0x6c lib/ubsan.c:291 ktime_mono_to_any+0x1d4/0x1e0 kernel/time/timekeeping.c:908 get_tcp_tstamp net/sched/sch_taprio.c:322 [inline] get_packet_txtime net/sched/sch_taprio.c:353 [inline] taprio_enqueue_one+0x5b0/0x1460 net/sched/sch_taprio.c:420 taprio_enqueue+0x3b1/0x730 net/sched/sch_taprio.c:485 dev_qdisc_enqueue+0x40/0x300 net/core/dev.c:3785 __dev_xmit_skb net/core/dev.c:3869 [inline] __dev_queue_xmit+0x1f6e/0x3630 net/core/dev.c:4194 batadv_send_skb_packet+0x4a9/0x5f0 net/batman-adv/send.c:108 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:393 [inline] batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:421 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x6d7/0x8e0 net/batman-adv/bat_iv_ogm.c:1701 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Fixes: 7ede7b03 ("taprio: make clock reference conversions easier") Fixes: 54002066 ("taprio: Adjust timestamps for TCP packets") Signed-off-by:Eric Dumazet <edumazet@google.com> Cc: Vedang Patel <vedang.patel@intel.com> Reported-by: