================================================================== BUG: KCSAN: data-race in mem_cgroup_flush_stats_ratelimited / tick_do_update_jiffies64 read-write to 0xffffffff86c07a00 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: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 get_ctx kernel/kcsan/core.c:206 [inline] check_access kernel/kcsan/core.c:750 [inline] __tsan_read8+0xe5/0x190 kernel/kcsan/core.c:1025 bio_associate_blkg_from_css+0x1ca/0x6b0 block/blk-cgroup.c:2149 bio_associate_blkg+0xc1/0xd0 block/blk-cgroup.c:2177 bio_init block/bio.c:239 [inline] bio_alloc_bioset+0x533/0x640 block/bio.c:605 bio_alloc include/linux/bio.h:367 [inline] io_submit_init_bio fs/ext4/page-io.c:428 [inline] io_submit_add_bh fs/ext4/page-io.c:464 [inline] ext4_bio_write_folio+0x731/0xa20 fs/ext4/page-io.c:609 mpage_submit_folio fs/ext4/inode.c:2103 [inline] mpage_process_page_bufs+0x4a1/0x620 fs/ext4/inode.c:2214 mpage_prepare_extent_to_map+0x7d4/0xc50 fs/ext4/inode.c:2753 ext4_do_writepages+0x6fe/0x2770 fs/ext4/inode.c:2894 ext4_writepages+0x18f/0x320 fs/ext4/inode.c:3042 do_writepages+0x1c6/0x310 mm/page-writeback.c:2571 __writeback_single_inode+0x7f/0x650 fs/fs-writeback.c:1764 writeback_sb_inodes+0x4dd/0xaa0 fs/fs-writeback.c:2056 __writeback_inodes_wb+0x94/0x1a0 fs/fs-writeback.c:2132 wb_writeback+0x261/0x560 fs/fs-writeback.c:2243 wb_check_start_all fs/fs-writeback.c:2369 [inline] wb_do_writeback fs/fs-writeback.c:2395 [inline] wb_workfn+0x4d1/0x930 fs/fs-writeback.c:2428 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0x4f0/0x9c0 kernel/workqueue.c:3385 worker_thread+0x58a/0x780 kernel/workqueue.c:3466 kthread+0x22a/0x280 kernel/kthread.c:436 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 read to 0xffffffff86c07a00 of 8 bytes by task 6307 on cpu 0: mem_cgroup_flush_stats_ratelimited+0x29/0x50 mm/memcontrol.c:743 count_shadow_nodes+0x6a/0x250 mm/workingset.c:692 do_shrink_slab+0x63/0x660 mm/shrinker.c:382 shrink_slab_memcg mm/shrinker.c:553 [inline] shrink_slab+0x545/0x8f0 mm/shrinker.c:631 shrink_node_memcgs mm/vmscan.c:6173 [inline] shrink_node+0x6d4/0x20a0 mm/vmscan.c:6215 shrink_zones mm/vmscan.c:6454 [inline] do_try_to_free_pages+0x408/0xc90 mm/vmscan.c:6516 try_to_free_mem_cgroup_pages+0x201/0x420 mm/vmscan.c:6838 try_charge_memcg+0x373/0xa10 mm/memcontrol.c:2627 obj_cgroup_charge_pages mm/memcontrol.c:3069 [inline] __memcg_kmem_charge_page+0x1ce/0x3d0 mm/memcontrol.c:3113 __alloc_frozen_pages_noprof+0x18a/0x350 mm/page_alloc.c:5243 __alloc_pages_noprof mm/page_alloc.c:5260 [inline] alloc_pages_bulk_noprof+0x4d1/0x560 mm/page_alloc.c:5180 alloc_pages_bulk_mempolicy_noprof+0x35b/0xeb0 mm/mempolicy.c:2798 vm_area_alloc_pages mm/vmalloc.c:3700 [inline] __vmalloc_area_node mm/vmalloc.c:3878 [inline] __vmalloc_node_range_noprof+0x891/0x11c0 mm/vmalloc.c:4064 __kvmalloc_node_noprof+0x3d4/0x640 mm/slub.c:6860 futex_hash_allocate+0x190/0x9a0 kernel/futex/core.c:1815 futex_hash_prctl+0xd8/0xf0 kernel/futex/core.c:1961 __do_sys_prctl kernel/sys.c:2885 [inline] __se_sys_prctl+0x4f4/0x1400 kernel/sys.c:2534 __x64_sys_prctl+0x67/0x80 kernel/sys.c:2534 x64_sys_call+0x2533/0x3020 arch/x86/include/generated/asm/syscalls_64.h:158 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: 0x00000000ffffd375 -> 0x00000000ffffd376 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 6307 Comm: syz.0.569 Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 ================================================================== syz.0.569 invoked oom-killer: gfp_mask=0x402dc2(GFP_KERNEL_ACCOUNT|__GFP_HIGHMEM|__GFP_ZERO|__GFP_NOWARN), order=0, oom_score_adj=1000 CPU: 0 UID: 0 PID: 6307 Comm: syz.0.569 Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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:464 oom_kill_process+0x295/0x350 mm/oom_kill.c:1031 out_of_memory+0x97d/0xb80 mm/oom_kill.c:1169 mem_cgroup_out_of_memory mm/memcontrol.c:1907 [inline] mem_cgroup_oom mm/memcontrol.c:1930 [inline] try_charge_memcg+0x62f/0xa10 mm/memcontrol.c:2669 obj_cgroup_charge_pages mm/memcontrol.c:3069 [inline] __memcg_kmem_charge_page+0x1ce/0x3d0 mm/memcontrol.c:3113 __alloc_frozen_pages_noprof+0x18a/0x350 mm/page_alloc.c:5243 alloc_pages_mpol+0xb3/0x260 mm/mempolicy.c:2490 alloc_frozen_pages_noprof mm/mempolicy.c:2561 [inline] alloc_pages_noprof+0x8f/0x140 mm/mempolicy.c:2581 vm_area_alloc_pages mm/vmalloc.c:3728 [inline] __vmalloc_area_node mm/vmalloc.c:3878 [inline] __vmalloc_node_range_noprof+0xaed/0x11c0 mm/vmalloc.c:4064 __kvmalloc_node_noprof+0x3d4/0x640 mm/slub.c:6860 futex_hash_allocate+0x190/0x9a0 kernel/futex/core.c:1815 futex_hash_prctl+0xd8/0xf0 kernel/futex/core.c:1961 __do_sys_prctl kernel/sys.c:2885 [inline] __se_sys_prctl+0x4f4/0x1400 kernel/sys.c:2534 __x64_sys_prctl+0x67/0x80 kernel/sys.c:2534 x64_sys_call+0x2533/0x3020 arch/x86/include/generated/asm/syscalls_64.h:158 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 RIP: 0033:0x7fd5ef67cdd9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd5ee0d7028 EFLAGS: 00000246 ORIG_RAX: 000000000000009d RAX: ffffffffffffffda RBX: 00007fd5ef8f5fa0 RCX: 00007fd5ef67cdd9 RDX: 0000000001000000 RSI: 0000000000000001 RDI: 000000000000004e RBP: 00007fd5ef712d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd5ef8f6038 R14: 00007fd5ef8f5fa0 R15: 00007ffe7ab900f8 memory: usage 307200kB, limit 307200kB, failcnt 3494 memory+swap: usage 310680kB, limit 9007199254740988kB, failcnt 0 kmem: usage 294864kB, limit 9007199254740988kB, failcnt 0 Memory cgroup stats for /syz0: cache 8192 rss 8388608 shmem 0 mapped_file 0 dirty 0 writeback 0 workingset_refault_anon 6372 workingset_refault_file 2781 swap 4112384 swapcached 47292416 pgpgin 210520 pgpgout 208470 pgfault 206972 pgmajfault 1704 inactive_anon 0 active_anon 0 inactive_file 0 active_file 8192 unevictable 8388608 hierarchical_memory_limit 314572800 hierarchical_memsw_limit 9223372036854771712 total_cache 8192 total_rss 8388608 total_shmem 0 total_mapped_file 0 total_dirty 0 total_writeback 0 total_workingset_refault_anon 6372 total_workingset_refault_file 2781 total_swap 4112384 total_swapcached 47292416 total_pgpgin 210520 total_pgpgout 208470 total_pgfault 206972 total_pgmajfault 1704 total_inactive_anon 0 total_active_anon 0 total_inactive_file 0 total_active_file 8192 total_unevictable 8388608 oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null),cpuset=syz0,mems_allowed=0,oom_memcg=/syz0,task_memcg=/syz0,task=syz.0.569,pid=6306,uid=0 Memory cgroup out of memory: Killed process 6306 (syz.0.569) total-vm:98536kB, anon-rss:9420kB, file-rss:26572kB, shmem-rss:0kB, UID:0 pgtables:152kB oom_score_adj:1000