================================================================== BUG: KCSAN: data-race in ktime_get / timekeeping_update_from_shadow write to 0xffffffff893a8488 of 304 bytes by interrupt on cpu 1: timekeeping_update_from_shadow+0x40d/0x440 kernel/time/timekeeping.c:829 __timekeeping_advance+0xa5d/0xc10 kernel/time/timekeeping.c:2532 timekeeping_advance kernel/time/timekeeping.c:2540 [inline] update_wall_time+0x21/0x50 kernel/time/timekeeping.c:2550 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:1930 [inline] __hrtimer_run_queues+0x276/0x4f0 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x261/0x850 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x5f/0x1c0 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0x6f/0x80 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 kcsan_setup_watchpoint+0x404/0x410 kernel/kcsan/core.c:705 lru_gen_in_fault include/linux/mm_inline.h:124 [inline] folio_add_lru+0x50/0x1f0 mm/swap.c:514 shmem_alloc_and_add_folio mm/shmem.c:2034 [inline] shmem_get_folio_gfp+0x7b0/0xd60 mm/shmem.c:2564 shmem_fault+0xf6/0x250 mm/shmem.c:2765 __do_fault mm/memory.c:5458 [inline] do_read_fault mm/memory.c:5893 [inline] do_fault mm/memory.c:6027 [inline] do_pte_missing mm/memory.c:4550 [inline] handle_pte_fault mm/memory.c:6411 [inline] __handle_mm_fault mm/memory.c:6549 [inline] handle_mm_fault+0x16cd/0x2e70 mm/memory.c:6718 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x1290/0x1f10 mm/gup.c:1428 populate_vma_page_range mm/gup.c:1860 [inline] __mm_populate+0x242/0x390 mm/gup.c:1963 mm_populate include/linux/mm.h:4137 [inline] vm_mmap_pgoff+0x23b/0x2d0 mm/util.c:586 ksys_mmap_pgoff+0xc1/0x310 mm/mmap.c:606 x64_sys_call+0x14df/0x3020 arch/x86/include/generated/asm/syscalls_64.h:10 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffffffff893a84a8 of 8 bytes by interrupt on cpu 0: timekeeping_cycles_to_ns kernel/time/timekeeping.c:444 [inline] timekeeping_get_ns kernel/time/timekeeping.c:449 [inline] ktime_get+0x130/0x240 kernel/time/timekeeping.c:967 ktime_get_ns include/linux/timekeeping.h:175 [inline] tcp_clock_ns include/net/tcp.h:983 [inline] tcp_mstamp_refresh+0x14/0x70 net/ipv4/tcp_output.c:60 tcp_rcv_established+0x6f/0x1320 net/ipv4/tcp_input.c:6477 tcp_v4_do_rcv+0x3c5/0xa40 net/ipv4/tcp_ipv4.c:1851 tcp_v4_rcv+0x1861/0x1bb0 net/ipv4/tcp_ipv4.c:2244 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_sublist_rcv_finish net/ipv4/ip_input.c:623 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:675 [inline] ip_sublist_rcv+0x5a4/0x6a0 net/ipv4/ip_input.c:683 ip_list_rcv+0x261/0x290 net/ipv4/ip_input.c:717 __netif_receive_skb_list_ptype net/core/dev.c:6245 [inline] __netif_receive_skb_list_core+0x4dc/0x500 net/core/dev.c:6292 __netif_receive_skb_list net/core/dev.c:6344 [inline] netif_receive_skb_list_internal+0x47d/0x5f0 net/core/dev.c:6435 gro_normal_list include/net/gro.h:523 [inline] gro_flush_normal include/net/gro.h:531 [inline] napi_complete_done+0x19c/0x3f0 net/core/dev.c:6803 virtqueue_napi_complete drivers/net/virtio_net.c:740 [inline] virtnet_poll+0x1b33/0x1fc0 drivers/net/virtio_net.c:3021 __napi_poll+0x61/0x300 net/core/dev.c:7733 napi_poll net/core/dev.c:7796 [inline] net_rx_action+0x452/0x930 net/core/dev.c:7953 handle_softirqs+0xb9/0x280 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x42/0xd0 kernel/softirq.c:735 common_interrupt+0x83/0x90 arch/x86/kernel/irq.c:326 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688 its_return_thunk+0x0/0x10 ptep_get include/linux/pgtable.h:461 [inline] queue_folios_pte_range+0x180/0x920 mm/mempolicy.c:711 walk_pmd_range mm/pagewalk.c:148 [inline] walk_pud_range mm/pagewalk.c:239 [inline] walk_p4d_range mm/pagewalk.c:280 [inline] walk_pgd_range+0xa76/0x1520 mm/pagewalk.c:321 __walk_page_range+0xdd/0x340 mm/pagewalk.c:429 walk_page_range_mm_unsafe+0x3e4/0x530 mm/pagewalk.c:525 walk_page_range+0x56/0x70 mm/pagewalk.c:604 queue_pages_range mm/mempolicy.c:996 [inline] migrate_to_node mm/mempolicy.c:1314 [inline] do_migrate_pages+0x3e1/0x640 mm/mempolicy.c:1418 kernel_migrate_pages mm/mempolicy.c:1932 [inline] __do_sys_migrate_pages mm/mempolicy.c:1950 [inline] __se_sys_migrate_pages+0x780/0x840 mm/mempolicy.c:1946 __x64_sys_migrate_pages+0x55/0x70 mm/mempolicy.c:1946 x64_sys_call+0x2983/0x3020 arch/x86/include/generated/asm/syscalls_64.h:257 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x0034e1f78e376bb6 -> 0x00357a8e0e66cf7c Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 7781 Comm: syz.8.897 Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 ==================================================================