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BUG: KCSAN: data-race in ktime_get_with_offset / timekeeping_update_from_shadow

write to 0xffffffff893a7488 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
 check_access kernel/kcsan/core.c:747 [inline]
 __tsan_read8+0xb7/0x190 kernel/kcsan/core.c:1025
 avtab_search_node+0x241/0x2b0 security/selinux/ss/avtab.c:155
 context_struct_compute_av+0x343/0xaf0 security/selinux/ss/services.c:664
 security_compute_av+0x34f/0xa20 security/selinux/ss/services.c:1177
 avc_compute_av+0x5d/0x430 security/selinux/avc.c:992
 avc_perm_nonode+0x5e/0xe0 security/selinux/avc.c:1117
 avc_has_perm_noaudit+0xf2/0x130 security/selinux/avc.c:1160
 cred_has_capability+0x121/0x2a0 security/selinux/hooks.c:1666
 selinux_capable+0x31/0x40 security/selinux/hooks.c:2189
 security_capable+0x7b/0x90 security/security.c:660
 ns_capable_common kernel/capability.c:342 [inline]
 ns_capable kernel/capability.c:363 [inline]
 capable_wrt_inode_uidgid+0x6f/0x190 kernel/capability.c:478
 generic_permission+0x2c8/0x470 fs/namei.c:554
 do_inode_permission fs/namei.c:585 [inline]
 inode_permission+0x17a/0x3b0 fs/namei.c:648
 may_open+0x255/0x350 fs/namei.c:4276
 do_open fs/namei.c:4697 [inline]
 path_openat+0x1a59/0x2050 fs/namei.c:4858
 do_file_open+0x16c/0x290 fs/namei.c:4887
 do_sys_openat2+0x94/0x130 fs/open.c:1364
 do_sys_open fs/open.c:1370 [inline]
 __do_sys_openat fs/open.c:1386 [inline]
 __se_sys_openat fs/open.c:1381 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1381
 x64_sys_call+0x1e39/0x3020 arch/x86/include/generated/asm/syscalls_64.h:258
 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 0xffffffff893a7498 of 8 bytes by task 29328 on cpu 1:
 timekeeping_cycles_to_ns kernel/time/timekeeping.c:426 [inline]
 timekeeping_get_ns kernel/time/timekeeping.c:449 [inline]
 ktime_get_with_offset+0xed/0x260 kernel/time/timekeeping.c:1011
 ktime_get_real include/linux/timekeeping.h:88 [inline]
 netif_receive_skb_list_internal+0x1b4/0x5f0 net/core/dev.c:6412
 netif_receive_skb_list+0x33/0x1c0 net/core/dev.c:6487
 xdp_recv_frames net/bpf/test_run.c:269 [inline]
 xdp_test_run_batch net/bpf/test_run.c:350 [inline]
 bpf_test_run_xdp_live+0x104c/0x1360 net/bpf/test_run.c:379
 bpf_prog_test_run_xdp+0x57b/0xa10 net/bpf/test_run.c:1430
 bpf_prog_test_run+0x204/0x340 kernel/bpf/syscall.c:4742
 __sys_bpf+0x52e/0x7e0 kernel/bpf/syscall.c:6266
 __do_sys_bpf kernel/bpf/syscall.c:6361 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6359 [inline]
 __x64_sys_bpf+0x41/0x50 kernel/bpf/syscall.c:6359
 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+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x000001b7f53175c0 -> 0x000001b7f6812e6f

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 29328 Comm: syz.7.7848 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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