================================================================== BUG: KCSAN: data-race in pcpu_alloc / pcpu_block_update_hint_alloc read-write to 0xffffffff884034dc of 4 bytes by task 8355 on cpu 0: pcpu_update_empty_pages mm/percpu.c:602 [inline] pcpu_block_update_hint_alloc+0x5db/0x6a0 mm/percpu.c:923 pcpu_alloc_area+0x49f/0x4d0 mm/percpu.c:1258 pcpu_alloc+0x4b3/0x10d0 mm/percpu.c:1808 __alloc_percpu_gfp+0x26/0x30 mm/percpu.c:1930 bpf_map_alloc_percpu+0xab/0x200 kernel/bpf/syscall.c:466 prealloc_init+0x19f/0x470 kernel/bpf/hashtab.c:338 htab_map_alloc+0x637/0x8f0 kernel/bpf/hashtab.c:573 map_create+0x83c/0xb90 kernel/bpf/syscall.c:1320 __sys_bpf+0x667/0x7a0 kernel/bpf/syscall.c:5642 __do_sys_bpf kernel/bpf/syscall.c:5767 [inline] __se_sys_bpf kernel/bpf/syscall.c:5765 [inline] __x64_sys_bpf+0x43/0x50 kernel/bpf/syscall.c:5765 x64_sys_call+0x86c/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:322 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+0x77/0x7f read to 0xffffffff884034dc of 4 bytes by task 8353 on cpu 1: pcpu_alloc+0x9aa/0x10d0 mm/percpu.c:1868 __alloc_percpu_gfp+0x26/0x30 mm/percpu.c:1930 bpf_map_alloc_percpu+0xab/0x200 kernel/bpf/syscall.c:466 prealloc_init+0x19f/0x470 kernel/bpf/hashtab.c:338 htab_map_alloc+0x637/0x8f0 kernel/bpf/hashtab.c:573 map_create+0x83c/0xb90 kernel/bpf/syscall.c:1320 __sys_bpf+0x667/0x7a0 kernel/bpf/syscall.c:5642 __do_sys_bpf kernel/bpf/syscall.c:5767 [inline] __se_sys_bpf kernel/bpf/syscall.c:5765 [inline] __x64_sys_bpf+0x43/0x50 kernel/bpf/syscall.c:5765 x64_sys_call+0x86c/0x2d30 arch/x86/include/generated/asm/syscalls_64.h:322 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+0x77/0x7f value changed: 0x00000004 -> 0xffffffff Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 8353 Comm: syz-executor.0 Not tainted 6.9.0-rc4-syzkaller-00034-g4b6b51322118 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 ==================================================================