================================================================== BUG: KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64 read-write to 0xffffffff86c09a00 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+0x218/0x4f0 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/0x1f0 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 preempt_count arch/x86/include/asm/preempt.h:27 [inline] check_kcov_mode kernel/kcov.c:183 [inline] __sanitizer_cov_trace_pc+0x17/0x70 kernel/kcov.c:217 __unix_dgram_recvmsg+0x49c/0x860 net/unix/af_unix.c:2610 unix_dgram_recvmsg+0x81/0x90 net/unix/af_unix.c:2670 sock_recvmsg_nosec+0xc2/0xf0 net/socket.c:1078 ____sys_recvmsg+0x26f/0x280 net/socket.c:2810 ___sys_recvmsg+0x11f/0x3b0 net/socket.c:2854 do_recvmmsg+0x1ef/0x560 net/socket.c:2949 __sys_recvmmsg net/socket.c:3023 [inline] __do_sys_recvmmsg net/socket.c:3046 [inline] __se_sys_recvmmsg net/socket.c:3039 [inline] __x64_sys_recvmmsg+0xe5/0x170 net/socket.c:3039 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/0x370 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f read to 0xffffffff86c09a00 of 8 bytes by task 24790 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+0x63/0x6a0 mm/shrinker.c:384 shrink_slab_memcg mm/shrinker.c:550 [inline] shrink_slab+0x538/0x880 mm/shrinker.c:628 shrink_node_memcgs mm/vmscan.c:6022 [inline] shrink_node+0x6bc/0x2130 mm/vmscan.c:6061 shrink_zones mm/vmscan.c:6300 [inline] do_try_to_free_pages+0x408/0xc80 mm/vmscan.c:6362 try_to_free_mem_cgroup_pages+0x1f5/0x470 mm/vmscan.c:6683 try_charge_memcg+0x37e/0xa10 mm/memcontrol.c:2414 try_charge mm/memcontrol.c:2556 [inline] charge_memcg mm/memcontrol.c:4744 [inline] __mem_cgroup_charge+0x65/0x150 mm/memcontrol.c:4761 mem_cgroup_charge include/linux/memcontrol.h:664 [inline] shmem_alloc_and_add_folio mm/shmem.c:1982 [inline] shmem_get_folio_gfp+0x47b/0xd60 mm/shmem.c:2567 shmem_get_folio mm/shmem.c:2673 [inline] shmem_write_begin+0xfc/0x1f0 mm/shmem.c:3327 generic_perform_write+0x183/0x490 mm/filemap.c:4319 shmem_file_write_iter+0xc5/0xf0 mm/shmem.c:3502 __kernel_write_iter+0x319/0x590 fs/read_write.c:621 dump_emit_page fs/coredump.c:1299 [inline] dump_user_range+0xa7d/0xdb0 fs/coredump.c:1373 elf_core_dump+0x21a2/0x2330 fs/binfmt_elf.c:2110 coredump_write+0xacc/0xdd0 fs/coredump.c:1050 do_coredump fs/coredump.c:1127 [inline] vfs_coredump+0x26c7/0x3130 fs/coredump.c:1201 get_signal+0xd80/0xf60 kernel/signal.c:3019 arch_do_signal_or_restart+0x96/0x450 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop kernel/entry/common.c:98 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline] irqentry_exit+0xf7/0x520 kernel/entry/common.c:219 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 value changed: 0x000000010000b727 -> 0x000000010000b728 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 24790 Comm: syz.2.4886 Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 ================================================================== syz.2.4886 invoked oom-killer: gfp_mask=0xcc0(GFP_KERNEL), order=0, oom_score_adj=1000 CPU: 0 UID: 0 PID: 24790 Comm: syz.2.4886 Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack+0x1d/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x95/0xd0 lib/dump_stack.c:120 dump_stack+0x15/0x1b lib/dump_stack.c:129 dump_header+0x80/0x240 mm/oom_kill.c:467 oom_kill_process+0x295/0x350 mm/oom_kill.c:1047 out_of_memory+0x97d/0xb80 mm/oom_kill.c:1185 mem_cgroup_out_of_memory mm/memcontrol.c:1695 [inline] mem_cgroup_oom mm/memcontrol.c:1718 [inline] try_charge_memcg+0x62e/0xa10 mm/memcontrol.c:2456 try_charge mm/memcontrol.c:2556 [inline] charge_memcg mm/memcontrol.c:4744 [inline] __mem_cgroup_charge+0x65/0x150 mm/memcontrol.c:4761 mem_cgroup_charge include/linux/memcontrol.h:664 [inline] shmem_alloc_and_add_folio mm/shmem.c:1982 [inline] shmem_get_folio_gfp+0x47b/0xd60 mm/shmem.c:2567 shmem_get_folio mm/shmem.c:2673 [inline] shmem_write_begin+0xfc/0x1f0 mm/shmem.c:3327 generic_perform_write+0x183/0x490 mm/filemap.c:4319 shmem_file_write_iter+0xc5/0xf0 mm/shmem.c:3502 __kernel_write_iter+0x319/0x590 fs/read_write.c:621 dump_emit_page fs/coredump.c:1299 [inline] dump_user_range+0xa7d/0xdb0 fs/coredump.c:1373 elf_core_dump+0x21a2/0x2330 fs/binfmt_elf.c:2110 coredump_write+0xacc/0xdd0 fs/coredump.c:1050 do_coredump fs/coredump.c:1127 [inline] vfs_coredump+0x26c7/0x3130 fs/coredump.c:1201 get_signal+0xd80/0xf60 kernel/signal.c:3019 arch_do_signal_or_restart+0x96/0x450 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop kernel/entry/common.c:98 [inline] __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:270 [inline] irqentry_exit_to_user_mode include/linux/irq-entry-common.h:339 [inline] irqentry_exit+0xf7/0x520 kernel/entry/common.c:219 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7ff09b912777 Code: e8 8e fa ff ff 89 f2 48 8d 3d 0d 41 1b 00 48 8d 35 f4 fa 1d 00 31 c0 e8 e7 f8 ff ff 0f 1f 80 00 00 00 00 53 89 fb 48 83 ec 10 <64> 8b 04 25 a4 ff ff ff 85 c0 74 2a 89 fe 31 c0 bf 3c 00 00 00 e8 RSP: 002b:00007ff09a456120 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007ff09ba5c799 RDX: 00007ff09a456140 RSI: 00007ff09a456270 RDI: 000000000000000b RBP: 00007ff09baf2c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007ff09bcd6218 R14: 00007ff09bcd6180 R15: 00007ffdda5cc818 memory: usage 306680kB, limit 307200kB, failcnt 38784 memory+swap: usage 431252kB, limit 9007199254740988kB, failcnt 0 kmem: usage 3868kB, limit 9007199254740988kB, failcnt 0 Memory cgroup stats for /syz2: cache 309481472 rss 81920 shmem 308244480 mapped_file 983040 dirty 0 writeback 0 workingset_refault_anon 419 workingset_refault_file 6618 swap 127565824 swapcached 234422272 pgpgin 863525 pgpgout 787892 pgfault 615641 pgmajfault 284 inactive_anon 115240960 active_anon 192520192 inactive_file 0 active_file 1236992 unevictable 0 hierarchical_memory_limit 314572800 hierarchical_memsw_limit 9223372036854771712 total_cache 309481472 total_rss 81920 total_shmem 308244480 total_mapped_file 983040 total_dirty 0 total_writeback 0 total_workingset_refault_anon 419 total_workingset_refault_file 6618 total_swap 127565824 total_swapcached 234422272 total_pgpgin 863525 total_pgpgout 787892 total_pgfault 615641 total_pgmajfault 284 total_inactive_anon 115240960 total_active_anon 192520192 total_inactive_file 0 total_active_file 1236992 total_unevictable 0 oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null),cpuset=/,mems_allowed=0,oom_memcg=/syz2,task_memcg=/syz2,task=syz.2.4886,pid=24818,uid=0 Memory cgroup out of memory: Killed process 24818 (syz.2.4886) total-vm:90456kB, anon-rss:1244kB, file-rss:54144kB, shmem-rss:0kB, UID:0 pgtables:192kB oom_score_adj:1000