================================================================== BUG: KCSAN: data-race in __wb_writeout_add / writeout_period write to 0xffffffff87126d70 of 8 bytes by interrupt on cpu 0: writeout_period+0xa6/0xe0 mm/page-writeback.c:614 call_timer_fn+0x37/0x2f0 kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1751 [inline] __run_timers+0x448/0x630 kernel/time/timer.c:2038 run_timer_softirq+0x31/0x40 kernel/time/timer.c:2053 __do_softirq+0xc4/0x27b kernel/softirq.c:553 invoke_softirq kernel/softirq.c:427 [inline] __irq_exit_rcu kernel/softirq.c:632 [inline] irq_exit_rcu+0x3b/0x90 kernel/softirq.c:644 sysvec_apic_timer_interrupt+0x6f/0x80 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 check_access kernel/kcsan/core.c:747 [inline] __tsan_read8+0xb3/0x180 kernel/kcsan/core.c:1025 propagate_protected_usage mm/page_counter.c:22 [inline] page_counter_cancel+0x7c/0x1c0 mm/page_counter.c:60 page_counter_uncharge+0x22/0x60 mm/page_counter.c:158 memcg_account_kmem mm/memcontrol.c:3262 [inline] obj_cgroup_uncharge_pages+0x1f1/0x200 mm/memcontrol.c:3279 __memcg_kmem_uncharge_page+0x53/0x100 mm/memcontrol.c:3353 free_pages_prepare mm/page_alloc.c:1097 [inline] free_unref_page_prepare+0x61/0x2c0 mm/page_alloc.c:2346 free_unref_page+0x34/0x170 mm/page_alloc.c:2486 vfree+0x211/0x390 mm/vmalloc.c:2842 __vmalloc_area_node mm/vmalloc.c:3203 [inline] __vmalloc_node_range+0xdf9/0xec0 mm/vmalloc.c:3320 kvmalloc_node+0x121/0x170 mm/util.c:642 kvmalloc include/linux/slab.h:728 [inline] xt_alloc_table_info+0x3d/0x80 net/netfilter/x_tables.c:1192 do_replace net/ipv4/netfilter/arp_tables.c:970 [inline] do_arpt_set_ctl+0x634/0x13c0 net/ipv4/netfilter/arp_tables.c:1421 nf_setsockopt+0x18d/0x1b0 net/netfilter/nf_sockopt.c:101 ip_setsockopt+0xe6/0x100 net/ipv4/ip_sockglue.c:1420 udp_setsockopt+0x95/0xa0 net/ipv4/udp.c:2783 sock_common_setsockopt+0x61/0x70 net/core/sock.c:3715 do_sock_setsockopt net/socket.c:2311 [inline] __sys_setsockopt+0x1d4/0x240 net/socket.c:2334 __do_sys_setsockopt net/socket.c:2343 [inline] __se_sys_setsockopt net/socket.c:2340 [inline] __x64_sys_setsockopt+0x66/0x80 net/socket.c:2340 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b read to 0xffffffff87126d70 of 8 bytes by task 30218 on cpu 1: wb_domain_writeout_add mm/page-writeback.c:563 [inline] __wb_writeout_add+0x8a/0x1d0 mm/page-writeback.c:584 __folio_end_writeback+0x21b/0x4a0 mm/page-writeback.c:2963 folio_end_writeback+0x74/0x1f0 mm/filemap.c:1599 ext4_finish_bio+0x47b/0x8e0 fs/ext4/page-io.c:145 ext4_release_io_end+0x8c/0x1e0 fs/ext4/page-io.c:160 ext4_end_io_end fs/ext4/page-io.c:194 [inline] ext4_do_flush_completed_IO fs/ext4/page-io.c:259 [inline] ext4_end_io_rsv_work+0x2d3/0x360 fs/ext4/page-io.c:273 process_one_work kernel/workqueue.c:2633 [inline] process_scheduled_works+0x5b8/0xa40 kernel/workqueue.c:2706 worker_thread+0x525/0x730 kernel/workqueue.c:2787 kthread+0x1d7/0x210 kernel/kthread.c:388 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:243 value changed: 0x000000010004b025 -> 0x000000010004b151 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 30218 Comm: kworker/u4:15 Not tainted 6.8.0-rc6-syzkaller-00120-g87adedeba51a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Workqueue: ext4-rsv-conversion ext4_end_io_rsv_work ==================================================================