BUG: soft lockup in batadv_dat_purge

Status: auto-obsoleted due to no activity on 2023/09/06 15:35
Reported-by: syzbot+50365ba3affd9babaf65@syzkaller.appspotmail.com
First crash: 1167d, last: 1167d
▶ ▼ Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in batadv_dat_purge (3) batman 1 1 454d 454d 0/29 auto-obsoleted due to no activity on 2025/08/09 21:42
linux-5.15 INFO: rcu detected stall in batadv_dat_purge 1 2 239d 259d 0/3 auto-obsoleted due to no activity on 2026/03/22 01:34
upstream INFO: rcu detected stall in batadv_dat_purge (4) batman 1 syz error error 1 204d 204d 0/29 closed as invalid on 2026/04/30 15:35
upstream INFO: rcu detected stall in batadv_dat_purge (2) kernel 1 1 1312d 1312d 0/29 auto-obsoleted due to no activity on 2023/04/12 18:40
linux-6.1 INFO: rcu detected stall in batadv_dat_purge 1 1 3d15h 3d15h 0/3 upstream: reported on 2026/08/05 08:00
upstream INFO: rcu detected stall in batadv_dat_purge batman 1 1 1761d 1761d 0/29 auto-closed as invalid on 2022/01/10 03:55

Sample crash report:
watchdog: BUG: soft lockup - CPU#0 stuck for 21s! [kworker/u4:2:148]
Modules linked in:
irq event stamp: 7053485
hardirqs last  enabled at (7053483): [<ffff8000081b4dac>] __local_bh_enable_ip+0x258/0x4d0 kernel/softirq.c:388
hardirqs last disabled at (7053485): [<ffff80001194f688>] enter_el1_irq_or_nmi+0x10/0x1c arch/arm64/kernel/entry-common.c:227
softirqs last  enabled at (7053482): [<ffff80001174ffe4>] spin_unlock_bh include/linux/spinlock.h:408 [inline]
softirqs last  enabled at (7053482): [<ffff80001174ffe4>] __batadv_dat_purge+0x2d4/0x374 net/batman-adv/distributed-arp-table.c:187
softirqs last disabled at (7053484): [<ffff80001174fe08>] spin_lock_bh include/linux/spinlock.h:368 [inline]
softirqs last disabled at (7053484): [<ffff80001174fe08>] __batadv_dat_purge+0xf8/0x374 net/batman-adv/distributed-arp-table.c:175
CPU: 0 PID: 148 Comm: kworker/u4:2 Not tainted 5.15.113-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
Workqueue: bat_events batadv_dat_purge
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : lock_acquire+0x280/0x77c
lr : lockdep_recursion_finish kernel/locking/lockdep.c:436 [inline]
lr : lock_acquire+0x24c/0x77c kernel/locking/lockdep.c:5624
sp : ffff80001a3c7920
x29: ffff80001a3c7a10 x28: ffff700003478f2c x27: 0000000000000000
x26: ffff0001b47fbd00 x25: ffff0001257be1d8 x24: 0000000000000000
x23: 0000000100000201 x22: ffff0000c5429b40 x21: ffff800014830d00
x20: dfff800000000000 x19: ffff0001b47fbd00 x18: 0000000000000000
x17: ff8080000fd27aa0 x16: ffff80001195113c x15: ffff80000fd27aa0
x14: 1ffff0000291c06a x13: ffffffffffffffff x12: 0000000000000000
x11: ff8080000a9a3a24 x10: 0000000000000003 x9 : 0000000000000080
x8 : 00000000000000c0 x7 : ffff80001174fe08 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000008 x1 : ffff800011aabf00 x0 : 0000000000000000
Call trace:
 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline]
 lock_acquire+0x280/0x77c kernel/locking/lockdep.c:5625
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x124/0x1c4 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:368 [inline]
 __batadv_dat_purge+0xf8/0x374 net/batman-adv/distributed-arp-table.c:175
 batadv_dat_purge+0x34/0x154 net/batman-adv/distributed-arp-table.c:206
 process_one_work+0x790/0x11b8 kernel/workqueue.c:2307
 worker_thread+0x910/0x1034 kernel/workqueue.c:2454
 kthread+0x37c/0x45c kernel/kthread.c:319
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/05/29 15:34 linux-5.15.y 1fe619a7d252 cf184559 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 BUG: soft lockup in batadv_dat_purge
* Struck through repros no longer work on HEAD.