syzbot

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BUG: KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64

read-write to 0xffffffff86809a00 of 8 bytes by interrupt on cpu 1:
 tick_do_update_jiffies64+0x113/0x1c0 kernel/time/tick-sched.c:118
 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:1777 [inline]
 __hrtimer_run_queues+0x20f/0x5a0 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x21a/0x460 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
 __sysvec_apic_timer_interrupt+0x5f/0x1d0 arch/x86/kernel/apic/apic.c:1062
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0x6f/0x80 arch/x86/kernel/apic/apic.c:1056
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
 is_atomic kernel/kcsan/core.c:264 [inline]
 should_watch kernel/kcsan/core.c:277 [inline]
 check_access kernel/kcsan/core.c:752 [inline]
 __tsan_read8+0x102/0x190 kernel/kcsan/core.c:1025
 folio_test_anon include/linux/page-flags.h:724 [inline]
 zap_present_folio_ptes mm/memory.c:1625 [inline]
 zap_present_ptes mm/memory.c:1708 [inline]
 do_zap_pte_range mm/memory.c:1810 [inline]
 zap_pte_range mm/memory.c:1854 [inline]
 zap_pmd_range mm/memory.c:1946 [inline]
 zap_pud_range mm/memory.c:1975 [inline]
 zap_p4d_range mm/memory.c:1996 [inline]
 unmap_page_range+0xd15/0x2530 mm/memory.c:2017
 unmap_single_vma mm/memory.c:2059 [inline]
 unmap_vmas+0x23d/0x3a0 mm/memory.c:2101
 exit_mmap+0x1ae/0x6b0 mm/mmap.c:1277
 __mmput+0x28/0x1c0 kernel/fork.c:1173
 mmput+0x40/0x50 kernel/fork.c:1196
 exit_mm+0xe4/0x180 kernel/exit.c:581
 do_exit+0x427/0x15d0 kernel/exit.c:959
 do_group_exit+0xff/0x140 kernel/exit.c:1112
 get_signal+0xe58/0xf70 kernel/signal.c:3034
 arch_do_signal_or_restart+0x96/0x450 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x6a/0x740 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x202/0x2a0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffffffff86809a00 of 8 bytes by task 2715 on cpu 0:
 mem_cgroup_flush_stats_ratelimited+0x29/0x70 mm/memcontrol.c:636
 count_shadow_nodes+0x6a/0x230 mm/workingset.c:678
 do_shrink_slab+0x63/0x680 mm/shrinker.c:384
 shrink_slab_memcg mm/shrinker.c:550 [inline]
 shrink_slab+0x4f5/0x840 mm/shrinker.c:628
 shrink_node_memcgs mm/vmscan.c:6020 [inline]
 shrink_node+0x6a9/0x2010 mm/vmscan.c:6059
 shrink_zones mm/vmscan.c:6298 [inline]
 do_try_to_free_pages+0x3f6/0xcd0 mm/vmscan.c:6360
 try_to_free_mem_cgroup_pages+0x1ab/0x410 mm/vmscan.c:6688
 try_charge_memcg+0x383/0xa10 mm/memcontrol.c:2388
 try_charge mm/memcontrol.c:2530 [inline]
 charge_memcg+0x51/0xc0 mm/memcontrol.c:4728
 mem_cgroup_swapin_charge_folio+0xcc/0x150 mm/memcontrol.c:4814
 __read_swap_cache_async+0x17b/0x2d0 mm/swap_state.c:481
 swap_cluster_readahead+0x362/0x3c0 mm/swap_state.c:665
 swapin_readahead+0xde/0x820 mm/swap_state.c:821
 do_swap_page+0x2b4/0x21e0 mm/memory.c:4753
 handle_pte_fault mm/memory.c:6276 [inline]
 __handle_mm_fault mm/memory.c:6411 [inline]
 handle_mm_fault+0x9d8/0x2c60 mm/memory.c:6580
 do_user_addr_fault+0x3fe/0x1080 arch/x86/mm/fault.c:1387
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
 __get_user_8+0x14/0x30 arch/x86/lib/getuser.S:100
 fetch_robust_entry kernel/futex/core.c:1139 [inline]
 exit_robust_list+0x31/0x280 kernel/futex/core.c:1167
 futex_cleanup kernel/futex/core.c:1411 [inline]
 futex_exit_release+0xe0/0x130 kernel/futex/core.c:1512
 exit_mm_release+0x1a/0x30 kernel/fork.c:1493
 exit_mm+0x38/0x180 kernel/exit.c:554
 do_exit+0x427/0x15d0 kernel/exit.c:959
 do_group_exit+0xff/0x140 kernel/exit.c:1112
 get_signal+0xe58/0xf70 kernel/signal.c:3034
 arch_do_signal_or_restart+0x96/0x450 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x6a/0x740 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x202/0x2a0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000100008535 -> 0x0000000100008536

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 2715 Comm: syz.0.9178 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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