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BUG: KCSAN: data-race in ktime_get / timekeeping_update_from_shadow

write to 0xffffffff893bb588 of 304 bytes by interrupt on cpu 0:
 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
 __copy_msghdr net/socket.c:2542 [inline]
 copy_msghdr_from_user net/socket.c:2590 [inline]
 recvmsg_copy_msghdr net/socket.c:2843 [inline]
 ___sys_recvmsg+0x1c3/0x3b0 net/socket.c:2915
 do_recvmmsg+0x1ef/0x560 net/socket.c:3014
 __sys_recvmmsg net/socket.c:3088 [inline]
 __do_sys_recvmmsg net/socket.c:3111 [inline]
 __se_sys_recvmmsg net/socket.c:3104 [inline]
 __x64_sys_recvmmsg+0xe5/0x170 net/socket.c:3104
 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/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff893bb5a8 of 8 bytes by task 10848 on cpu 1:
 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
 futex_init_timeout kernel/futex/syscalls.c:182 [inline]
 __do_sys_futex kernel/futex/syscalls.c:201 [inline]
 __se_sys_futex+0x243/0x370 kernel/futex/syscalls.c:188
 __x64_sys_futex+0x78/0x90 kernel/futex/syscalls.c:188
 x64_sys_call+0x24ab/0x3020 arch/x86/include/generated/asm/syscalls_64.h:203
 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: 0x0008f0d998ccfeee -> 0x0009897018fc62b4

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 10848 Comm: syz.6.1179 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
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