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BUG: KCSAN: data-race in ktime_get / timekeeping_update_from_shadow

write to 0xffffffff89395488 of 304 bytes by interrupt on cpu 0:
 timekeeping_update_from_shadow+0x40d/0x440 kernel/time/timekeeping.c:829
 __timekeeping_advance+0xa68/0xc10 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+0x88/0x3d0 kernel/time/tick-sched.c:312
 __run_hrtimer kernel/time/hrtimer.c:1930 [inline]
 __hrtimer_run_queues+0x1f8/0x510 kernel/time/hrtimer.c:1994
 hrtimer_interrupt+0x257/0x810 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
 __sanitizer_cov_trace_pc+0x42/0x70 kernel/kcov.c:220
 __unix_dgram_recvmsg+0x494/0x860 net/unix/af_unix.c:2626
 unix_dgram_recvmsg+0x7e/0x90 net/unix/af_unix.c:2686
 sock_recvmsg_nosec+0xc2/0xf0 net/socket.c:1138
 ____sys_recvmsg+0x26f/0x280 net/socket.c:2917
 ___sys_recvmsg+0x11f/0x3a0 net/socket.c:2961
 do_recvmmsg+0x1e5/0x560 net/socket.c:3056
 __sys_recvmmsg net/socket.c:3130 [inline]
 __do_sys_recvmmsg net/socket.c:3153 [inline]
 __se_sys_recvmmsg net/socket.c:3146 [inline]
 __x64_sys_recvmmsg+0xe5/0x170 net/socket.c:3146
 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+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff89395498 of 8 bytes by task 7315 on cpu 1:
 timekeeping_cycles_to_ns kernel/time/timekeeping.c:426 [inline]
 timekeeping_get_ns kernel/time/timekeeping.c:449 [inline]
 ktime_get+0xcf/0x240 kernel/time/timekeeping.c:967
 ktime_get_ns include/linux/timekeeping.h:175 [inline]
 bpf_test_timer_enter net/bpf/test_run.c:40 [inline]
 bpf_test_timer_continue+0x2ea/0x350 net/bpf/test_run.c:75
 bpf_test_run+0x2f3/0x620 net/bpf/test_run.c:427
 bpf_prog_test_run_skb+0xe67/0x11b0 net/bpf/test_run.c:1192
 bpf_prog_test_run+0x208/0x340 kernel/bpf/syscall.c:4742
 __sys_bpf+0x52e/0x7e0 kernel/bpf/syscall.c:6292
 __do_sys_bpf kernel/bpf/syscall.c:6387 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6385 [inline]
 __x64_sys_bpf+0x41/0x50 kernel/bpf/syscall.c:6385
 x64_sys_call+0x10cb/0x3020 arch/x86/include/generated/asm/syscalls_64.h:322
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x000001b5146bafe2 -> 0x000001b515bb67ca

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 7315 Comm: syz.4.11063 Tainted: G        W           syzkaller #0 PREEMPT(lazy) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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