syzbot


KCSAN: data-race in prandom_seed / prandom_u32

Status: moderation: reported syz repro on 2021/03/31 03:56
Reported-by: syzbot+2d36aedecb5ce6dc3c93@syzkaller.appspotmail.com
First crash: 497d, last: 41d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in prandom_seed / prandom_u32

write to 0xffff888237c28850 of 8 bytes by task 34 on cpu 0:
 siprand_u32 lib/random32.c:372 [inline]
 prandom_u32+0x11f/0x190 lib/random32.c:387
 mld_ifc_start_work net/ipv6/mcast.c:1071 [inline]
 mld_ifc_work+0x6dd/0x800 net/ipv6/mcast.c:2656
 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289
 worker_thread+0x618/0xa70 kernel/workqueue.c:2436
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30

read to 0xffff888237c28850 of 8 bytes by task 1914 on cpu 1:
 prandom_seed+0xd3/0x270 lib/random32.c:439
 addrconf_dad_begin net/ipv6/addrconf.c:3975 [inline]
 addrconf_dad_work+0x265/0xbb0 net/ipv6/addrconf.c:4100
 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289
 worker_thread+0x618/0xa70 kernel/workqueue.c:2436
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30

value changed: 0x03399c5a4ec7427f -> 0xf8cccffa14535866

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1914 Comm: kworker/1:7 Not tainted 5.18.0-rc7-syzkaller-00015-gef1302160bfb-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: ipv6_addrconf addrconf_dad_work
==================================================================

Crashes (612):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/05/18 19:47 upstream ef1302160bfb 50c53f39 .config log report syz KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/24 10:35 upstream 143a6252e1b8 fcfad4ff .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/23 23:19 upstream 140e40e39a29 e7f9308d .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/23 09:13 upstream 4b0986a3613c 7268fa62 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/22 21:07 upstream 978df3e15846 7268fa62 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/22 06:38 upstream eaea45fc0e7b 7268fa62 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/21 17:29 upstream 6c3f5bec9b40 7268fa62 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/21 04:12 upstream 3b5e1590a267 7268fa62 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/20 14:58 upstream 3d7285a335ed cb1ac2e7 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/20 01:13 upstream b015dcd62b86 cb1ac2e7 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/19 12:12 upstream f993aed406ea cb1ac2e7 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/19 06:00 upstream f993aed406ea 50c53f39 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/18 16:51 upstream ef1302160bfb 50c53f39 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/18 14:05 upstream 210e04ff7681 50c53f39 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/18 00:19 upstream 210e04ff7681 744a39e2 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/16 03:28 upstream 42226c989789 744a39e2 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/15 14:18 upstream bc403203d65a 744a39e2 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/15 00:13 upstream 2fe1020d73ca 744a39e2 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/14 10:38 upstream ec7f49619d8e 744a39e2 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/13 22:03 upstream f2dd007445b1 107f6434 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/13 09:28 upstream f3f19f939c11 7ce5a022 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/13 08:12 upstream f3f19f939c11 9ad6612a .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/12 19:01 upstream 0ac824f379fb 9ad6612a .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/12 15:49 upstream feb9c5e19e91 9ad6612a .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/11 16:58 upstream feb9c5e19e91 beb0b407 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/10 23:26 upstream feb9c5e19e91 8d7b3b67 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/09 16:23 upstream 9be9ed2612b5 8b277b8e .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/09 08:18 upstream c5eb0a61238d e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/09 06:45 upstream c5eb0a61238d e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/09 05:40 upstream c5eb0a61238d e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/09 04:28 upstream c5eb0a61238d e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/09 02:56 upstream c5eb0a61238d e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/09 01:43 upstream c5eb0a61238d e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/09 00:03 upstream 379c72654524 e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/08 22:40 upstream 379c72654524 e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/08 21:35 upstream 379c72654524 e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/08 19:53 upstream 379c72654524 e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/08 18:34 upstream 379c72654524 e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/08 17:33 upstream 30c8e80f7932 e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/08 16:03 upstream 30c8e80f7932 e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/08 14:56 upstream 30c8e80f7932 e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/08 13:42 upstream 30c8e80f7932 e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/08 11:54 upstream 30c8e80f7932 e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/08 10:50 upstream 30c8e80f7932 e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/08 09:22 upstream 30c8e80f7932 e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/08 08:23 upstream 30c8e80f7932 e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/08 06:32 upstream 30c8e80f7932 e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/08 05:07 upstream 30c8e80f7932 e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/08 03:45 upstream 30c8e80f7932 e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2022/05/08 02:18 upstream 30c8e80f7932 e60b1103 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2021/03/30 18:06 upstream 2bb25b3a748a 6a81331a .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2021/03/27 03:45 upstream 0f4498cef9f5 a8529b82 .config log report info KCSAN: data-race in prandom_seed / prandom_u32
ci2-upstream-kcsan-gce 2021/02/22 08:14 upstream 31caf8b2a847 a659b3f1 .config log report info KCSAN: data-race in prandom_seed / prandom_u32