================================================================== BUG: KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn read-write to 0xffffffff88315a4c of 4 bytes by task 9780 on cpu 1: pcpu_update_empty_pages mm/percpu.c:558 [inline] pcpu_chunk_populated mm/percpu.c:1492 [inline] __pcpu_balance_workfn mm/percpu.c:2032 [inline] pcpu_balance_workfn+0xc05/0xdd0 mm/percpu.c:2068 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275 worker_thread+0x635/0xb90 kernel/workqueue.c:2421 kthread+0x1fd/0x220 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 read to 0xffffffff88315a4c of 4 bytes by task 8472 on cpu 0: pcpu_alloc+0xa9b/0x1020 mm/percpu.c:1834 __alloc_percpu+0x20/0x30 mm/percpu.c:1906 xt_percpu_counter_alloc+0x6e/0x110 net/netfilter/x_tables.c:1820 find_check_entry net/ipv4/netfilter/ip_tables.c:527 [inline] translate_table+0x95f/0xfa0 net/ipv4/netfilter/ip_tables.c:717 ipt_register_table+0x9a/0x280 net/ipv4/netfilter/ip_tables.c:1732 iptable_mangle_table_init+0x70/0x90 net/ipv4/netfilter/iptable_mangle.c:97 xt_find_table_lock+0x1bf/0x2d0 net/netfilter/x_tables.c:1223 xt_request_find_table_lock+0x22/0xa0 net/netfilter/x_tables.c:1253 get_info net/ipv4/netfilter/ip_tables.c:964 [inline] do_ipt_get_ctl+0x4ee/0xe60 net/ipv4/netfilter/ip_tables.c:1651 nf_getsockopt+0x18f/0x1b0 net/netfilter/nf_sockopt.c:116 ip_getsockopt+0xf8d/0x1200 net/ipv4/ip_sockglue.c:1777 tcp_getsockopt+0x13f/0x15d0 net/ipv4/tcp.c:4142 sock_common_getsockopt+0x53/0x60 net/core/sock.c:3222 __sys_getsockopt+0x1ed/0x340 net/socket.c:2156 __do_sys_getsockopt net/socket.c:2171 [inline] __se_sys_getsockopt net/socket.c:2168 [inline] __x64_sys_getsockopt+0x62/0x70 net/socket.c:2168 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 8472 Comm: syz-executor.0 Not tainted 5.11.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================