syzbot


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

Status: auto-closed as invalid on 2021/05/18 12:20
Subsystems: bpf
[Documentation on labels]
Reported-by: syzbot+ef7a33de7d8ace59d619@syzkaller.appspotmail.com
First crash: 1258d, last: 1070d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area netfilter 1 1437d 1437d 0/26 auto-closed as invalid on 2020/06/18 13:23
upstream KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area (2) netfilter 1 1353d 1353d 0/26 auto-closed as invalid on 2020/08/08 10:36

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

write to 0xffffffff88f3dccc of 4 bytes by task 18529 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
 map_create kernel/bpf/syscall.c:905 [inline]
 __do_sys_bpf+0x92cb/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

read to 0xffffffff88f3dccc of 4 bytes by task 9115 on cpu 1:
 __pcpu_balance_workfn mm/percpu.c:2002 [inline]
 pcpu_balance_workfn+0x9a2/0xf10 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

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 9115 Comm: kworker/1:4 Not tainted 5.12.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events pcpu_balance_workfn
==================================================================

Crashes (32):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/04/13 12:20 upstream 89698becf06d 6a81331a .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/04/11 13:52 upstream 52e44129fba5 6a81331a .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/03/30 00:17 upstream 1e43c377a79f 6a81331a .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/03/28 07:21 upstream 0f4498cef9f5 a8529b82 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/03/25 23:04 upstream 002322402daf 6a383ecf .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/03/25 17:29 upstream e138138003eb 6a383ecf .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/03/20 05:38 upstream 8b12a62a4e3e 3d01c4de .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/03/17 07:25 upstream 1df27313f50a fdb2bb2c .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/03/16 00:33 upstream 1e28eed17697 fdb2bb2c .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/03/13 17:53 upstream f296bfd5cd04 4a003785 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/03/09 00:49 upstream 144c79ef3353 09fbf400 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/02/21 11:26 upstream e767b3530acb 3e5ed8b4 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/02/21 04:28 upstream f40ddce88593 3e5ed8b4 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/02/18 10:31 upstream f40ddce88593 14052202 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/02/11 11:30 upstream 291009f656e8 a52ee10a .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/02/09 17:58 upstream e0756cfc7d7c 2bd9619f .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/02/04 14:44 upstream 61556703b610 42b90a7c .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/02/01 07:23 upstream 1048ba83fb1c fc9fd31e .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/01/23 19:54 upstream fe75a21824e7 52e37319 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/01/22 01:17 upstream 9791581c049c d4f4eca5 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/01/19 15:13 upstream 1e2a199f6ccd 63631df1 .config console log report info ci2-upstream-kcsan-gce KCSAN: data-race in pcpu_balance_workfn / pcpu_free_area
2021/01/11 01:27 upstream 0653161f0fac 2c1f2513 .config console log report info ci2-upstream-kcsan-gce
2021/01/05 17:28 upstream 36bbbd0e234d a0234d98 .config console log report info ci2-upstream-kcsan-gce
2021/01/01 06:02 upstream f6e1ea196492 79264ae3 .config console log report info ci2-upstream-kcsan-gce
2020/12/28 23:29 upstream c76e02c59e13 8259d56c .config console log report info ci2-upstream-kcsan-gce
2020/12/27 00:00 upstream 40f78232f973 821e0b09 .config console log report info ci2-upstream-kcsan-gce
2020/12/26 09:50 upstream 5814bc2d4cc2 821e0b09 .config console log report info ci2-upstream-kcsan-gce
2020/12/20 04:53 upstream 467f8165a2b0 04201c06 .config console log report info ci2-upstream-kcsan-gce
2020/12/17 19:20 upstream accefff5b547 04201c06 .config console log report info ci2-upstream-kcsan-gce
2020/11/11 07:10 upstream eccc87672492 cca87986 .config console log report info ci2-upstream-kcsan-gce
2020/11/05 13:27 upstream 4ef8451b3326 cba33199 .config console log report info ci2-upstream-kcsan-gce
2020/10/07 10:22 upstream c85fb28b6f99 1880b4a9 .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.