================================================================== BUG: KCSAN: data-race in pcpu_alloc / pcpu_free_area write to 0xffffffff88f3dccc of 4 bytes by task 9736 on cpu 0: pcpu_update_empty_pages mm/percpu.c:559 [inline] pcpu_block_update_hint_free mm/percpu.c:994 [inline] pcpu_free_area+0x597/0x640 mm/percpu.c:1254 free_percpu+0x1cb/0x740 mm/percpu.c:2102 htab_free_elems kernel/bpf/hashtab.c:243 [inline] prealloc_destroy+0xee/0x1a0 kernel/bpf/hashtab.c:337 htab_map_free+0x45/0x340 kernel/bpf/hashtab.c:1373 bpf_map_free_deferred+0xb2/0x110 kernel/bpf/syscall.c:459 process_one_work+0x3e1/0x950 kernel/workqueue.c:2275 worker_thread+0x616/0xa70 kernel/workqueue.c:2421 kthread+0x20b/0x230 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 read to 0xffffffff88f3dccc of 4 bytes by task 17223 on cpu 1: pcpu_alloc+0xb11/0x10a0 mm/percpu.c:1835 __alloc_percpu_gfp+0x22/0x30 mm/percpu.c:1894 bpf_map_alloc_percpu+0xab/0x120 kernel/bpf/syscall.c:435 prealloc_init kernel/bpf/hashtab.c:296 [inline] htab_map_alloc+0x814/0xc80 kernel/bpf/hashtab.c:508 find_and_alloc_map kernel/bpf/syscall.c:122 [inline] map_create kernel/bpf/syscall.c:828 [inline] __do_sys_bpf+0x420c/0x99c0 kernel/bpf/syscall.c:4375 __se_sys_bpf kernel/bpf/syscall.c:4351 [inline] __x64_sys_bpf+0x3d/0x50 kernel/bpf/syscall.c:4351 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 17223 Comm: syz-executor.2 Not tainted 5.12.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================