bisecting fixing commit since ae4b064e2a616b545acf02b8f50cc513b32c7522
building syzkaller on 08003f6440deafc4e193b159c4acece64f7864b1
testing commit ae4b064e2a616b545acf02b8f50cc513b32c7522 with gcc (GCC) 8.1.0
kernel signature: 9a5b7f44f543ee30290d91d063cba86027aaf20fab11f3eb07b65233faf141f2
run #0: crashed: BUG: workqueue lockup
run #1: crashed: BUG: workqueue lockup
run #2: crashed: BUG: workqueue lockup
run #3: crashed: INFO: rcu detected stall in corrupted
run #4: crashed: INFO: rcu detected stall in corrupted
run #5: crashed: INFO: rcu detected stall in chrdev_open
run #6: crashed: BUG: workqueue lockup
run #7: crashed: INFO: rcu detected stall in corrupted
run #8: crashed: INFO: rcu detected stall in corrupted
run #9: crashed: INFO: rcu detected stall in corrupted
testing current HEAD 71c061d2443814de15e177489d5cc00a4a253ef3
testing commit 71c061d2443814de15e177489d5cc00a4a253ef3 with gcc (GCC) 8.1.0
kernel signature: 820e7bea8319158b42544873faeffca8b2285900a385afe8b5cf6749850ecb70
run #0: crashed: BUG: workqueue lockup
run #1: crashed: BUG: workqueue lockup
run #2: crashed: BUG: workqueue lockup
run #3: crashed: BUG: workqueue lockup
run #4: crashed: INFO: rcu detected stall in corrupted
run #5: crashed: BUG: workqueue lockup
run #6: basic kernel testing failed: failed to copy test binary to VM: failed to run ["scp" "-P" "22" "-F" "/dev/null" "-o" "UserKnownHostsFile=/dev/null" "-o" "BatchMode=yes" "-o" "IdentitiesOnly=yes" "-o" "StrictHostKeyChecking=no" "-o" "ConnectTimeout=10" "-i" "/syzkaller/jobs/linux/workdir/image/key" "/tmp/syz-executor919210172" "root@10.128.10.61:./syz-executor919210172"]: exit status 1
ssh: connect to host 10.128.10.61 port 22: Connection timed out
lost connection

run #7: crashed: BUG: workqueue lockup
run #8: crashed: BUG: workqueue lockup
run #9: crashed: BUG: workqueue lockup
revisions tested: 2, total time: 28m46.436808749s (build: 11m12.799010084s, test: 16m33.357121126s)
the crash still happens on HEAD
commit msg: Merge tag 'for-5.11-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
crash: BUG: workqueue lockup
BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 43s!
BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 42s!
Showing busy workqueues and worker pools:
workqueue events: flags=0x0
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=3/256 refcnt=4
    in-flight: 7001:nsim_dev_trap_report_work
    pending: cache_reap, perf_sched_delayed
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=15/256 refcnt=16
    in-flight: 14:nsim_dev_trap_report_work
    pending: nsim_dev_trap_report_work, nsim_dev_trap_report_work, nsim_dev_trap_report_work, nsim_dev_trap_report_work, vmstat_shepherd, cache_reap, ovs_dp_masks_rebalance, ovs_dp_masks_rebalance, ovs_dp_masks_rebalance, ovs_dp_masks_rebalance, psi_avgs_work, ovs_dp_masks_rebalance, ovs_dp_masks_rebalance, check_corruption
workqueue events_long: flags=0x0
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=4/256 refcnt=5
    pending: defense_work_handler, defense_work_handler, defense_work_handler, defense_work_handler
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=3/256 refcnt=4
    pending: defense_work_handler, defense_work_handler, defense_work_handler
workqueue events_freezable: flags=0x4
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: update_balloon_stats_func
workqueue events_power_efficient: flags=0x80
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=2/256 refcnt=3
    pending: do_cache_clean, neigh_periodic_work
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=4/256 refcnt=5
    pending: fb_flashcursor, gc_worker, check_lifetime, neigh_periodic_work
workqueue mm_percpu_wq: flags=0x8
  pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: vmstat_update
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: vmstat_update
workqueue netns: flags=0xe000a
  pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/1 refcnt=4
    in-flight: 700:cleanup_net
    delayed: cleanup_net
workqueue writeback: flags=0x4a
  pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/256 refcnt=3
    in-flight: 7:wb_workfn
workqueue dm_bufio_cache: flags=0x8
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2
    pending: work_fn
workqueue ipv6_addrconf: flags=0x40008
  pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/1 refcnt=2
    pending: addrconf_verify_work
workqueue bat_events: flags=0xe000a
  pwq 4: cpus=0-1 flags=0x4 nice=0 active=1/1 refcnt=32
    in-flight: 475:batadv_nc_worker
    delayed: batadv_nc_worker, batadv_nc_worker, batadv_nc_worker, batadv_nc_worker, batadv_mcast_mla_update, batadv_mcast_mla_update, batadv_mcast_mla_update, batadv_mcast_mla_update, batadv_mcast_mla_update, batadv_purge_orig, batadv_purge_orig, batadv_purge_orig, batadv_purge_orig, batadv_purge_orig, batadv_tt_purge, batadv_tt_purge, batadv_dat_purge, batadv_dat_purge, batadv_bla_periodic_work, batadv_dat_purge, batadv_bla_periodic_work, batadv_dat_purge, batadv_bla_periodic_work, batadv_bla_periodic_work, batadv_tt_purge, batadv_tt_purge, batadv_tt_purge, batadv_bla_periodic_work, batadv_dat_purge
pool 0: cpus=0 node=0 flags=0x0 nice=0 hung=43s workers=4 idle: 1142 22483 5
pool 2: cpus=1 node=0 flags=0x0 nice=0 hung=42s workers=4 idle: 22486 22529 19
pool 4: cpus=0-1 flags=0x4 nice=0 hung=36s workers=5 idle: 331 1020