syzbot


KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn (3)

Status: auto-closed as invalid on 2021/05/17 09:01
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 770d, last: 673d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn 4 952d 962d 0/24 auto-closed as invalid on 2020/08/04 06:35
upstream KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn (2) 3 867d 901d 0/24 auto-closed as invalid on 2020/10/28 20:02
upstream KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn (4) 12 249d 419d 0/24 auto-closed as invalid on 2022/07/08 11:31

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

write to 0xffffffff88f3cccc of 4 bytes by task 9691 on cpu 1:
 pcpu_update_empty_pages mm/percpu.c:559 [inline]
 pcpu_chunk_populated mm/percpu.c:1493 [inline]
 __pcpu_balance_workfn mm/percpu.c:2033 [inline]
 pcpu_balance_workfn+0xc7c/0xe40 mm/percpu.c:2069
 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 0xffffffff88f3cccc of 4 bytes by task 5950 on cpu 0:
 pcpu_alloc+0xaed/0x1090 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: 0 PID: 5950 Comm: syz-executor.0 Tainted: G        W         5.12.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (12):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-upstream-kcsan-gce 2021/04/05 19:51 upstream 0a50438c8436 6a81331a .config console log report info KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn
ci2-upstream-kcsan-gce 2021/03/23 15:54 upstream 84196390620a e613994b .config console log report info KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn
ci2-upstream-kcsan-gce 2021/03/21 23:10 upstream 5ee96fa9dd78 4c9a64da .config console log report info KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn
ci2-upstream-kcsan-gce 2021/03/19 21:10 upstream 8b12a62a4e3e 3d01c4de .config console log report info KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn
ci2-upstream-kcsan-gce 2021/03/07 09:11 upstream a38fd8748464 c599ed12 .config console log report info KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn
ci2-upstream-kcsan-gce 2021/02/07 21:54 upstream b75dba7f472c 2ce644fc .config console log report info KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn
ci2-upstream-kcsan-gce 2021/02/06 23:50 upstream 964d069f93c4 0655e081 .config console log report info KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn
ci2-upstream-kcsan-gce 2021/02/03 20:33 upstream 3afe9076a7c1 624dad51 .config console log report info KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn
ci2-upstream-kcsan-gce 2021/01/24 20:12 upstream e68061375f79 52e37319 .config console log report info KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn
ci2-upstream-kcsan-gce 2021/01/22 19:44 upstream 83d09ad4b950 52e37319 .config console log report info KCSAN: data-race in pcpu_alloc / pcpu_balance_workfn
ci2-upstream-kcsan-gce 2020/12/29 13:28 upstream dea8dcf2a9fa 80910769 .config console log report info
ci2-upstream-kcsan-gce 2020/12/29 12:25 upstream dea8dcf2a9fa 8259d56c .config console log report info
* Struck through repros no longer work on HEAD.