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BUG: KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64

read-write to 0xffffffff86a09a00 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:1785 [inline]
 __hrtimer_run_queues+0x207/0x4c0 kernel/time/hrtimer.c:1849
 hrtimer_interrupt+0x269/0x810 kernel/time/hrtimer.c:1911
 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
 arch_atomic64_read arch/x86/include/asm/atomic64_64.h:15 [inline]
 raw_atomic64_read include/linux/atomic/atomic-arch-fallback.h:2583 [inline]
 raw_atomic_long_read include/linux/atomic/atomic-long.h:38 [inline]
 atomic_long_read include/linux/atomic/atomic-instrumented.h:3189 [inline]
 find_watchpoint kernel/kcsan/core.c:131 [inline]
 check_access kernel/kcsan/core.c:737 [inline]
 __tsan_read8+0x2c/0x190 kernel/kcsan/core.c:1025
 root_reclaim mm/vmscan.c:218 [inline]
 flush_reclaim_state mm/vmscan.c:338 [inline]
 shrink_one+0x23e/0x3f0 mm/vmscan.c:4927
 shrink_many mm/vmscan.c:4982 [inline]
 lru_gen_shrink_node mm/vmscan.c:5060 [inline]
 shrink_node+0x18b0/0x2000 mm/vmscan.c:6047
 kswapd_shrink_node mm/vmscan.c:6901 [inline]
 balance_pgdat mm/vmscan.c:7084 [inline]
 kswapd+0x1189/0x1d90 mm/vmscan.c:7354
 kthread+0x22a/0x280 kernel/kthread.c:467
 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffffffff86a09a00 of 8 bytes by task 7259 on cpu 0:
 mem_cgroup_flush_stats_ratelimited+0x29/0x70 mm/memcontrol.c:638
 count_shadow_nodes+0x6a/0x230 mm/workingset.c:678
 do_shrink_slab+0x63/0x670 mm/shrinker.c:384
 shrink_slab_memcg mm/shrinker.c:550 [inline]
 shrink_slab+0x538/0x880 mm/shrinker.c:628
 shrink_one+0x193/0x3f0 mm/vmscan.c:4921
 shrink_many mm/vmscan.c:4982 [inline]
 lru_gen_shrink_node mm/vmscan.c:5060 [inline]
 shrink_node+0x18b0/0x2000 mm/vmscan.c:6047
 shrink_zones mm/vmscan.c:6300 [inline]
 do_try_to_free_pages+0x404/0xcc0 mm/vmscan.c:6362
 try_to_free_pages+0x3ae/0x8f0 mm/vmscan.c:6608
 __perform_reclaim mm/page_alloc.c:4412 [inline]
 __alloc_pages_direct_reclaim+0x4e/0xd0 mm/page_alloc.c:4434
 __alloc_pages_slowpath+0x324/0x5c0 mm/page_alloc.c:4878
 __alloc_frozen_pages_noprof+0x270/0x350 mm/page_alloc.c:5258
 alloc_pages_mpol+0xb3/0x260 mm/mempolicy.c:2486
 alloc_frozen_pages_noprof mm/mempolicy.c:2557 [inline]
 alloc_pages_noprof+0x8f/0x130 mm/mempolicy.c:2577
 relay_alloc_buf kernel/relay.c:122 [inline]
 relay_create_buf kernel/relay.c:162 [inline]
 relay_open_buf+0x1da/0x8a0 kernel/relay.c:390
 relay_open+0x2e8/0x640 kernel/relay.c:519
 blk_trace_setup_prepare+0x242/0x300 kernel/trace/blktrace.c:716
 blk_trace_setup+0x246/0x3a0 kernel/trace/blktrace.c:789
 blk_trace_ioctl+0x211/0x640 kernel/trace/blktrace.c:935
 blkdev_ioctl+0x2ac/0x460 block/ioctl.c:781
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xce/0x140 fs/ioctl.c:583
 __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:583
 x64_sys_call+0x1563/0x3020 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x12c/0x370 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000000ffffcbd5 -> 0x00000000ffffcbd6

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 7259 Comm: syz.8.1051 Tainted: G        W           syzkaller #0 PREEMPT(full) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
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