Re: [syzbot] [arm?] BUG: workqueue lockup in batadv_tt_purge

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
BUG: workqueue lockup in nsim_fib_event_work

bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
BUG: workqueue lockup - pool cpus=1 node=0 flags=0x0 nice=0 stuck for 34s!
Showing busy workqueues and worker pools:
workqueue events: flags=0x100
  pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=4 refcnt=5
    pending: nsim_dev_hwstats_traffic_work, vmstat_shepherd, 2*ovs_dp_masks_rebalance
  pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=33 refcnt=34
    in-flight: 26:nsim_fib_event_work for 35s nsim_fib_event_work ,4951:nsim_fib_event_work for 31s ,1503:nsim_fib_event_work for 22s ,1091:nsim_fib_event_work for 15s
    pending: 3*nsim_dev_hwstats_traffic_work, 2*ovs_dp_masks_rebalance, psi_avgs_work, 3*ovs_dp_masks_rebalance, psi_avgs_work, drm_fb_helper_damage_work, 2*l2cap_info_timeout, psi_avgs_work, 2*l2cap_info_timeout, 4*ovs_dp_masks_rebalance, 3*rht_deferred_worker, psi_avgs_work, reg_todo, 3*nsim_fib_event_work
workqueue events_unbound: flags=0x2
  pwq 8: cpus=0-1 flags=0x6 nice=0 active=5 refcnt=6
    in-flight: 14:nsim_dev_trap_report_work for 5s
    pending: 2*nsim_dev_trap_report_work, toggle_allocation_gate, flush_memcg_stats_dwork
  pwq 8: cpus=0-1 flags=0x6 nice=0 active=15 refcnt=16
    in-flight: 5376:cfg80211_wiphy_work for 25s cfg80211_wiphy_work ,1178:cfg80211_wiphy_work for 32s cfg80211_wiphy_work ,1372:cfg80211_wiphy_work for 35s cfg80211_wiphy_work ,5377:nsim_dev_trap_report_work for 7s ,58:cfg80211_wiphy_work for 33s cfg80211_wiphy_work ,49:cfg80211_wiphy_work for 23s cfg80211_wiphy_work ,40:cfg80211_wiphy_work for 31s cfg80211_wiphy_work
    pending: 2*macvlan_process_broadcast
workqueue events_power_efficient: flags=0x82
  pwq 8: cpus=0-1 flags=0x6 nice=0 active=4 refcnt=5
    pending: fb_flashcursor, wg_ratelimiter_gc_entries, 2*neigh_managed_work
  pwq 8: cpus=0-1 flags=0x6 nice=0 active=3 refcnt=4
    in-flight: 1350:gc_worker for 16s ,144:neigh_periodic_work for 20s
    pending: do_cache_clean
workqueue events_dfl_long: flags=0x2
  pwq 8: cpus=0-1 flags=0x6 nice=0 active=11 refcnt=12
    pending: 11*defense_work_handler
workqueue netns: flags=0x6000a
  pwq 8: cpus=0-1 flags=0x6 nice=0 active=1 refcnt=4
    in-flight: 12:cleanup_net for 36s
workqueue mm_percpu_wq: flags=0x108
  pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2
    pending: vmstat_update
  pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2
    pending: vmstat_update
workqueue writeback: flags=0x4a
  pwq 8: cpus=0-1 flags=0x6 nice=0 active=1 refcnt=4 MAYDAY
    in-flight: 33(RESCUER):wb_workfn for 31s
workqueue mld: flags=0x40108
  pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=4
    pending: mld_dad_work
    inactive: 2*mld_dad_work
  pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=108
    pending: mld_dad_work
    inactive: mld_dad_work, 8*mld_ifc_work, 4*mld_dad_work, mld_ifc_work, mld_dad_work, 10*mld_ifc_work, mld_dad_work, 3*mld_ifc_work, mld_dad_work, 11*mld_ifc_work, mld_dad_work, mld_ifc_work, mld_dad_work, mld_ifc_work, 3*mld_dad_work, 10*mld_ifc_work, 3*mld_dad_work, 7*mld_ifc_work, 2*mld_dad_work, 3*mld_ifc_work, mld_dad_work, mld_ifc_work, mld_dad_work, mld_ifc_work, mld_dad_work, mld_ifc_work, mld_dad_work, 17*mld_ifc_work, mld_dad_work, 3*mld_ifc_work, 5*mld_dad_work
workqueue ipv6_addrconf: flags=0x6000a
  pwq 8: cpus=0-1 flags=0x6 nice=0 active=1 refcnt=248 MAYDAY
    in-flight: 2822(RESCUER):addrconf_dad_work for 0s
    pending: mayday_cursor_func
    inactive: 242*addrconf_dad_work
workqueue bat_events: flags=0x6000a
  pwq 8: cpus=0-1 flags=0x6 nice=0 active=1 refcnt=50 MAYDAY
    in-flight: 2854(RESCUER):batadv_dat_purge for 7s
    inactive: batadv_bla_periodic_work, batadv_dat_purge, batadv_bla_periodic_work, batadv_dat_purge, batadv_bla_periodic_work, batadv_dat_purge, batadv_bla_periodic_work, batadv_dat_purge, batadv_bla_periodic_work, batadv_iv_send_outstanding_bat_ogm_packet, batadv_mcast_mla_update, 4*batadv_iv_send_outstanding_bat_ogm_packet, batadv_purge_orig, 2*batadv_iv_send_outstanding_bat_ogm_packet, 4*batadv_purge_orig, 4*batadv_iv_send_outstanding_bat_ogm_packet, 2*batadv_tt_purge, 4*batadv_iv_send_outstanding_bat_ogm_packet, 3*batadv_tt_purge, batadv_mcast_mla_update, batadv_purge_orig, batadv_iv_send_outstanding_bat_ogm_packet, batadv_tt_purge, 4*batadv_mcast_mla_update, batadv_dat_purge
workqueue wg-kex-wg0: flags=0x6
  pwq 8: cpus=0-1 flags=0x6 nice=0 active=1 refcnt=2
    pending: wg_packet_handshake_send_worker
workqueue wg-crypt-wg0: flags=0x128
  pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2
    pending: wg_packet_encrypt_worker
  pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=2 refcnt=3
    pending: wg_packet_encrypt_worker, wg_packet_tx_worker
workqueue wg-kex-wg1: flags=0x6
  pwq 8: cpus=0-1 flags=0x6 nice=0 active=1 refcnt=2
    pending: wg_packet_handshake_send_worker
workqueue wg-crypt-wg1: flags=0x128
  pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=3 refcnt=4
    pending: wg_packet_decrypt_worker, wg_packet_encrypt_worker, wg_packet_tx_worker
workqueue wg-kex-wg2: flags=0x124
  pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=2 refcnt=3
    in-flight: 4767:wg_packet_handshake_receive_worker for 21s
    pending: wg_packet_handshake_receive_worker
  pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2
    pending: wg_packet_handshake_receive_worker
workqueue wg-crypt-wg2: flags=0x128
  pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2
    pending: wg_packet_encrypt_worker
  pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=3 refcnt=4
    pending: wg_packet_decrypt_worker, wg_packet_encrypt_worker, wg_packet_tx_worker
workqueue wg-kex-wg0: flags=0x6
  pwq 8: cpus=0-1 flags=0x6 nice=0 active=1 refcnt=2
    pending: wg_packet_handshake_send_worker
workqueue wg-crypt-wg0: flags=0x128
  pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2
    pending: wg_packet_encrypt_worker
  pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=2 refcnt=3
    pending: wg_packet_tx_worker, wg_packet_encrypt_worker
workqueue wg-crypt-wg1: flags=0x128
  pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=2 refcnt=3
    in-flight: 932:wg_packet_decrypt_worker for 22s
    pending: wg_packet_encrypt_worker
  pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=3 refcnt=4
    pending: wg_packet_encrypt_worker, wg_packet_decrypt_worker, wg_packet_tx_worker
workqueue wg-kex-wg2: flags=0x124
  pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2
    pending: wg_packet_handshake_receive_worker
workqueue wg-kex-wg2: flags=0x6
  pwq 8: cpus=0-1 flags=0x6 nice=0 active=1 refcnt=2
    pending: wg_packet_handshake_send_worker
workqueue wg-crypt-wg2: flags=0x128
  pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2
    pending: wg_packet_encrypt_worker
  pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=2 refcnt=3
    pending: wg_packet_encrypt_worker, wg_packet_decrypt_worker
workqueue wg-crypt-wg0: flags=0x128
  pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=3 refcnt=4
    in-flight: 4813:wg_packet_encrypt_worker for 14s
    pending: wg_packet_tx_worker, wg_packet_encrypt_worker
  pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=2 refcnt=3
    pending: wg_packet_tx_worker, wg_packet_encrypt_worker
workqueue wg-kex-wg0: flags=0x6
  pwq 8: cpus=0-1 flags=0x6 nice=0 active=1 refcnt=2
    pending: wg_packet_handshake_send_worker
workqueue wg-crypt-wg0: flags=0x128
  pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2
    pending: wg_packet_encrypt_worker
  pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=2 refcnt=3
    pending: wg_packet_tx_worker, wg_packet_encrypt_worker
workqueue wg-kex-wg1: flags=0x6
  pwq 8: cpus=0-1 flags=0x6 nice=0 active=1 refcnt=2
    pending: wg_packet_handshake_send_worker
workqueue wg-crypt-wg1: flags=0x128
  pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=2 refcnt=3
    pending: wg_packet_decrypt_worker, wg_packet_encrypt_worker
  pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=3 refcnt=4
    pending: wg_packet_encrypt_worker, wg_packet_decrypt_worker, wg_packet_tx_worker
workqueue wg-kex-wg2: flags=0x124
  pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=1 refcnt=2
    pending: wg_packet_handshake_receive_worker
workqueue wg-crypt-wg2: flags=0x128
  pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2
    pending: wg_packet_encrypt_worker
  pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=3 refcnt=4
    pending: wg_packet_encrypt_worker, wg_packet_decrypt_worker, wg_packet_tx_worker
workqueue wg-crypt-wg1: flags=0x128
  pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2
    pending: wg_packet_encrypt_worker
  pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=3 refcnt=4
    pending: wg_packet_encrypt_worker, wg_packet_decrypt_worker, wg_packet_tx_worker
workqueue wg-kex-wg2: flags=0x124
  pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2
    pending: wg_packet_handshake_receive_worker
workqueue wg-crypt-wg2: flags=0x128
  pwq 2: cpus=0 node=0 flags=0x0 nice=0 active=1 refcnt=2
    pending: wg_packet_encrypt_worker
  pwq 6: cpus=1 node=0 flags=0x0 nice=0 active=2 refcnt=3
    pending: wg_packet_decrypt_worker, wg_packet_encrypt_worker
pool 2: cpus=0 node=0 flags=0x0 nice=0 hung=14s workers=6 idle: 4847 9 10
pool 6: cpus=1 node=0 flags=0x0 nice=0 hung=34s workers=9 idle: 24 4738 5269 5303 4950
pool 8: cpus=0-1 flags=0x6 nice=0 hung=0s workers=12 manager: 5378
Showing backtraces of busy workers in stalled worker pools:
pool 6:
task:kworker/1:1     state:R  running task     stack:0     pid:26    tgid:26    ppid:2      task_flags:0x4208060 flags:0x00000010
Workqueue: events nsim_fib_event_work
Call trace:


Tested on:

commit:         532df11b batman-adv: tt: batch BH re-enable during TT ..
git tree:       https://git.open-mesh.org/batadv.git disable-bh
console output: https://syzkaller.appspot.com/x/log.txt?x=137967a5580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a3c0ea8c3fd76353
dashboard link: https://syzkaller.appspot.com/bug?extid=61b202fdc410840f0198
compiler:       Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8
userspace arch: arm64

Note: no patches were applied.