syzbot


KCSAN: data-race in bpf_percpu_array_update / bpf_percpu_array_update

Status: auto-closed as invalid on 2022/04/12 04:08
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 270d, last: 270d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in bpf_percpu_array_update / bpf_percpu_array_update

write to 0xffffe8ffff61dbb8 of 8 bytes by task 19504 on cpu 1:
 bpf_long_memcpy include/linux/bpf.h:1663 [inline]
 bpf_percpu_array_update+0x25c/0x3d0 kernel/bpf/arraymap.c:366
 bpf_map_update_value+0x181/0x2f0 kernel/bpf/syscall.c:199
 map_update_elem kernel/bpf/syscall.c:1181 [inline]
 __sys_bpf+0x6134/0xa3c0 kernel/bpf/syscall.c:4625
 __do_sys_bpf kernel/bpf/syscall.c:4741 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4739 [inline]
 __x64_sys_bpf+0x3f/0x50 kernel/bpf/syscall.c:4739
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

write to 0xffffe8ffff61dbb8 of 8 bytes by task 19503 on cpu 0:
 bpf_long_memcpy include/linux/bpf.h:1663 [inline]
 bpf_percpu_array_update+0x25c/0x3d0 kernel/bpf/arraymap.c:366
 bpf_map_update_value+0x181/0x2f0 kernel/bpf/syscall.c:199
 map_update_elem kernel/bpf/syscall.c:1181 [inline]
 __sys_bpf+0x6134/0xa3c0 kernel/bpf/syscall.c:4625
 __do_sys_bpf kernel/bpf/syscall.c:4741 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4739 [inline]
 __x64_sys_bpf+0x3f/0x50 kernel/bpf/syscall.c:4739
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000000000 -> 0x21aca4173a9f473e

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 19503 Comm: syz-executor.3 Not tainted 5.17.0-rc7-syzkaller-00020-gea4424be1688-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/03/08 04:00 upstream ea4424be1688 7bdd8b2c .config log report info KCSAN: data-race in bpf_percpu_array_update / bpf_percpu_array_update
* Struck through repros no longer work on HEAD.