syzbot

==================================================================
BUG: KCSAN: data-race in ktime_get / timekeeping_update_from_shadow

write to 0xffffffff893c6108 of 280 bytes by interrupt on cpu 1:
 timekeeping_update_from_shadow+0x2b4/0x2f0 kernel/time/timekeeping.c:753
 __timekeeping_advance+0xa5b/0xbe0 kernel/time/timekeeping.c:2377
 timekeeping_advance kernel/time/timekeeping.c:2385 [inline]
 update_wall_time+0x24/0x90 kernel/time/timekeeping.c:2395
 tick_do_update_jiffies64+0x169/0x1c0 kernel/time/tick-sched.c:149
 tick_sched_do_timer kernel/time/tick-sched.c:253 [inline]
 tick_nohz_handler+0x8d/0x3d0 kernel/time/tick-sched.c:312
 __run_hrtimer kernel/time/hrtimer.c:1785 [inline]
 __hrtimer_run_queues+0x218/0x4f0 kernel/time/hrtimer.c:1849
 hrtimer_interrupt+0x269/0x810 kernel/time/hrtimer.c:1911
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
 __sysvec_apic_timer_interrupt+0x5f/0x1f0 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0x32/0x80 arch/x86/kernel/apic/apic.c:1056
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
 preempt_count arch/x86/include/asm/preempt.h:27 [inline]
 check_kcov_mode kernel/kcov.c:183 [inline]
 write_comp_data kernel/kcov.c:246 [inline]
 __sanitizer_cov_trace_const_cmp1+0x17/0x90 kernel/kcov.c:300
 br_validate_ipv6+0xf6/0x460 net/bridge/br_netfilter_ipv6.c:58
 br_nf_pre_routing_ipv6+0x42/0x2e0 net/bridge/br_netfilter_ipv6.c:169
 br_nf_pre_routing+0x52b/0xbd0 net/bridge/br_netfilter_hooks.c:508
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
 br_handle_frame+0x85f/0xa60 net/bridge/br_input.c:442
 __netif_receive_skb_core+0x5b1/0x1980 net/core/dev.c:6054
 __netif_receive_skb_one_core net/core/dev.c:6165 [inline]
 __netif_receive_skb net/core/dev.c:6280 [inline]
 process_backlog+0x25b/0x670 net/core/dev.c:6631
 __napi_poll+0x61/0x330 net/core/dev.c:7695
 napi_poll net/core/dev.c:7758 [inline]
 net_rx_action+0x452/0x930 net/core/dev.c:7910
 handle_softirqs+0xb9/0x2a0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x39/0xc0 kernel/softirq.c:723
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0x74/0x80 arch/x86/kernel/apic/apic.c:1056
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
 __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:95 [inline]
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
 _raw_spin_unlock_irqrestore+0x1a/0x30 kernel/locking/spinlock.c:194
 __unix_dgram_recvmsg+0x3a7/0x860 net/unix/af_unix.c:2596
 unix_dgram_recvmsg+0x81/0x90 net/unix/af_unix.c:2670
 sock_recvmsg_nosec+0x107/0x130 net/socket.c:1078
 ____sys_recvmsg+0x26f/0x280 net/socket.c:2810
 ___sys_recvmsg+0x11f/0x3b0 net/socket.c:2854
 do_recvmmsg+0x1ef/0x560 net/socket.c:2949
 __sys_recvmmsg net/socket.c:3023 [inline]
 __do_sys_recvmmsg net/socket.c:3046 [inline]
 __se_sys_recvmmsg net/socket.c:3039 [inline]
 __x64_sys_recvmmsg+0xe5/0x170 net/socket.c:3039
 x64_sys_call+0x80f/0x3020 arch/x86/include/generated/asm/syscalls_64.h:300
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff893c6118 of 8 bytes by interrupt on cpu 0:
 timekeeping_cycles_to_ns kernel/time/timekeeping.c:381 [inline]
 timekeeping_get_ns kernel/time/timekeeping.c:404 [inline]
 ktime_get+0xcd/0x210 kernel/time/timekeeping.c:826
 ktime_get_ns include/linux/timekeeping.h:175 [inline]
 tcp_clock_ns include/net/tcp.h:940 [inline]
 tcp_mstamp_refresh+0x14/0x70 net/ipv4/tcp_output.c:60
 tcp_init_buffer_space net/ipv4/tcp_input.c:749 [inline]
 tcp_init_transfer+0x34c/0x5c0 net/ipv4/tcp_input.c:6762
 tcp_rcv_state_process+0x178e/0x21a0 net/ipv4/tcp_input.c:7294
 tcp_child_process+0x28b/0x430 net/ipv4/tcp_minisocks.c:1004
 tcp_v4_rcv+0x1592/0x1db0 net/ipv4/tcp_ipv4.c:2266
 ip_protocol_deliver_rcu+0x395/0x790 net/ipv4/ip_input.c:207
 ip_local_deliver_finish+0x1fc/0x2f0 net/ipv4/ip_input.c:241
 NF_HOOK include/linux/netfilter.h:318 [inline]
 ip_local_deliver+0xe8/0x1e0 net/ipv4/ip_input.c:262
 dst_input include/net/dst.h:480 [inline]
 ip_rcv_finish+0x194/0x1c0 net/ipv4/ip_input.c:453
 NF_HOOK include/linux/netfilter.h:318 [inline]
 ip_rcv+0x62/0x160 net/ipv4/ip_input.c:573
 __netif_receive_skb_one_core net/core/dev.c:6167 [inline]
 __netif_receive_skb net/core/dev.c:6280 [inline]
 process_backlog+0x341/0x670 net/core/dev.c:6631
 __napi_poll+0x61/0x330 net/core/dev.c:7695
 napi_poll net/core/dev.c:7758 [inline]
 net_rx_action+0x452/0x930 net/core/dev.c:7910
 handle_softirqs+0xb9/0x2a0 kernel/softirq.c:622
 do_softirq+0x45/0x60 kernel/softirq.c:523
 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:450
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:924 [inline]
 __dev_queue_xmit+0x136c/0x1f20 net/core/dev.c:4876
 dev_queue_xmit include/linux/netdevice.h:3384 [inline]
 neigh_hh_output include/net/neighbour.h:540 [inline]
 neigh_output include/net/neighbour.h:554 [inline]
 ip_finish_output2+0x705/0x8c0 net/ipv4/ip_output.c:237
 __ip_finish_output net/ipv4/ip_output.c:-1 [inline]
 ip_finish_output+0x114/0x2a0 net/ipv4/ip_output.c:325
 NF_HOOK_COND include/linux/netfilter.h:307 [inline]
 ip_output+0xbd/0x1c0 net/ipv4/ip_output.c:438
 dst_output include/net/dst.h:470 [inline]
 ip_local_out net/ipv4/ip_output.c:131 [inline]
 __ip_queue_xmit+0xbb0/0xbf0 net/ipv4/ip_output.c:534
 ip_queue_xmit+0x39/0x50 net/ipv4/ip_output.c:548
 __tcp_transmit_skb+0x1af2/0x1f10 net/ipv4/tcp_output.c:1693
 __tcp_send_ack+0x288/0x3b0 net/ipv4/tcp_output.c:4503
 tcp_send_ack_reflect_ect+0x61/0x70 net/ipv4/tcp_input.c:4038
 tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:7033 [inline]
 tcp_rcv_state_process+0x1e26/0x21a0 net/ipv4/tcp_input.c:7227
 tcp_v4_do_rcv+0x5fe/0xa30 net/ipv4/tcp_ipv4.c:1909
 sk_backlog_rcv include/net/sock.h:1185 [inline]
 __release_sock+0x15e/0x2f0 net/core/sock.c:3213
 release_sock+0x44/0x150 net/core/sock.c:3795
 inet_stream_connect+0x57/0x70 net/ipv4/af_inet.c:751
 kernel_connect+0x9f/0xf0 net/socket.c:3634
 rds_tcp_conn_path_connect+0x50d/0x5f0 net/rds/tcp_connect.c:205
 rds_connect_worker+0x12f/0x1b0 net/rds/threads.c:176
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0x4de/0x9e0 kernel/workqueue.c:3358
 worker_thread+0x581/0x770 kernel/workqueue.c:3439
 kthread+0x22a/0x280 kernel/kthread.c:467
 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

value changed: 0x0000005f0da4e812 -> 0x0000005f0ef4997f

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 70 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: krds_cp_wq#3/0 rds_connect_worker
==================================================================
EXT4-fs (loop1): error count since last fsck: 1
EXT4-fs (loop1): initial error at time 1772691826: ext4_validate_block_bitmap:432
EXT4-fs (loop1): last error at time 1772691826: ext4_validate_block_bitmap:432