syzbot


upstream test error: KCSAN: data-race in prandom_seed / prandom_u32

Status: auto-closed as invalid on 2022/01/10 22:18
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 354d, last: 354d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream upstream test error: KCSAN: data-race in prandom_seed / prandom_u32 (2) 1 188d 188d 0/24 auto-closed as invalid on 2022/06/26 06:37

Sample crash report:
IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready
==================================================================
BUG: KCSAN: data-race in prandom_seed / prandom_u32

read to 0xffff888237c28450 of 8 bytes by task 1821 on cpu 1:
 prandom_seed+0xd5/0x270 lib/random32.c:441
 addrconf_dad_begin net/ipv6/addrconf.c:3960 [inline]
 addrconf_dad_work+0x27a/0x1170 net/ipv6/addrconf.c:4085
 process_one_work+0x3fc/0x980 kernel/workqueue.c:2298
 worker_thread+0x616/0xa70 kernel/workqueue.c:2445
 kthread+0x2c7/0x2e0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30

write to 0xffff888237c28450 of 8 bytes by task 7 on cpu 0:
 siprand_u32 lib/random32.c:373 [inline]
 prandom_u32+0x11f/0x230 lib/random32.c:388
 mld_ifc_start_work net/ipv6/mcast.c:1071 [inline]
 mld_ifc_work+0x6eb/0x810 net/ipv6/mcast.c:2664
 process_one_work+0x3fc/0x980 kernel/workqueue.c:2298
 worker_thread+0x616/0xa70 kernel/workqueue.c:2445
 kthread+0x2c7/0x2e0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30

value changed: 0x87c9ae1c824e00f0 -> 0x2ce518c7a4ed9810

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7 Comm: kworker/0:1 Not tainted 5.16.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: mld mld_ifc_work

==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/12/06 22:14 upstream f80ef9e49fdf 0230ba3e .config log report upstream test error: KCSAN: data-race in prandom_seed / prandom_u32
* Struck through repros no longer work on HEAD.