INFO: task hung in exit_aio (3)

Status: premoderation: reported on 2026/08/15 21:55
Reported-by: syzbot+26c361ce1e94f8ec2fa3@syzkaller.appspotmail.com
First crash: 42d, last: 2d15h
▶ ▼ Similar bugs (8)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-12 INFO: task hung in exit_aio (2) 1 22 120d 234d 0/1 auto-obsoleted due to no activity on 2026/08/12 14:31
upstream INFO: task hung in exit_aio (5) prio:low fs 1 46 2d10h 132d 0/29 upstream: reported on 2026/05/17 16:41
upstream INFO: task hung in exit_aio (4) fs 1 6 652d 718d 0/29 auto-obsoleted due to no activity on 2025/03/13 05:51
android-414 INFO: task hung in exit_aio 1 3 2702d 2703d 0/1 auto-closed as invalid on 2019/10/25 08:40
upstream INFO: task hung in exit_aio (2) fs 1 3 1779d 1857d 0/29 closed as invalid on 2022/02/07 19:09
upstream INFO: task hung in exit_aio (3) fs 1 1 812d 812d 0/29 auto-obsoleted due to no activity on 2024/10/04 00:29
android-6-12 INFO: task hung in exit_aio 1 38 318d 460d 0/1 auto-obsoleted due to no activity on 2026/01/04 12:01
upstream INFO: task hung in exit_aio fs 1 syz, C 17519 2597d 3212d 0/29 closed as dup on 2018/04/08 22:50

Sample crash report:
INFO: task syz.1.251:1156 blocked for more than 123 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.251       state:D stack:0     pid:1156  tgid:1153  ppid:295    flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6063 [inline]
 __schedule+0x1496/0x20b0 kernel/sched/core.c:7883
 __schedule_loop kernel/sched/core.c:7960 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7975
 schedule_timeout+0xc7/0x3b0 kernel/time/timer.c:2596
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common+0x368/0x650 kernel/sched/completion.c:127
 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
 exit_aio+0x28d/0x360 fs/aio.c:927
 __mmput+0x2f/0x330 kernel/fork.c:1367
 mmput+0x55/0x170 kernel/fork.c:1394
 exit_mm kernel/exit.c:581 [inline]
 do_exit+0x9a5/0x2850 kernel/exit.c:948
 do_group_exit+0x21f/0x2f0 kernel/exit.c:1104
 get_signal+0x134c/0x1490 kernel/signal.c:2941
 arch_do_signal_or_restart+0xbc/0x700 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x57/0xb0 kernel/entry/common.c:218
 do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f0edeb9e159
RSP: 002b:00007f0edfb180e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f0edee26098 RCX: 00007f0edeb9e159
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f0edee26098
RBP: 00007f0edee26090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0edee26128 R14: 00007ffe4876f1a0 R15: 00007ffe4876f288
 </TASK>
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 b27277d6799ceeca3eb852bae8b5683c15874786
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
 dump_stack+0x19/0x20 lib/dump_stack.c:129
 nmi_cpu_backtrace+0x2ba/0x2d0 lib/nmi_backtrace.c:114
 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:63
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
 cpumask_backtrace+0x1f/0x30 lib/nmi_backtrace.c:127
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline]
 watchdog+0xe45/0xf90 kernel/hung_task.c:423
 kthread+0x2c7/0x360 kernel/kthread.c:389
 ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 1184 Comm: syz-executor Not tainted syzkaller #0 b27277d6799ceeca3eb852bae8b5683c15874786
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:unwind_get_return_address+0x0/0x90 arch/x86/kernel/unwind_frame.c:15
Code: 48 c7 c7 80 b9 4e 87 e8 9e ce 9b 00 e9 79 ff ff ff cc cc cc cc cc cc cc cc cc b8 49 9a dd ea 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 55 48 89 e5 41 57 41 56 53 48 89 fb 49 be 00 00 00 00
RSP: 0018:ffffc90000007220 EFLAGS: 00000202
RAX: 1ffff92000000e01 RBX: ffffc900000072e0 RCX: 0000000000000e01
RDX: ffffc9000e197350 RSI: 1ffff92000000e46 RDI: ffffc90000007228
RBP: ffffc900000072b0 R08: ffffc900000072f0 R09: ffffc900000072e8
R10: 0000000000000010 R11: ffffffff8175a7c0 R12: ffff8881244b9300
R13: 0000000002fcd401 R14: ffffffff8175a7c0 R15: ffffc90000007228
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4094bf84c0 CR3: 0000000121e14000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 00000000fda3b69a DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:49 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:70
 kasan_save_alloc_info+0x3a/0x50 mm/kasan/generic.c:565
 unpoison_slab_object mm/kasan/common.c:321 [inline]
 __kasan_slab_alloc+0x73/0x90 mm/kasan/common.c:347
 kasan_slab_alloc include/linux/kasan.h:251 [inline]
 slab_post_alloc_hook mm/slub.c:4202 [inline]
 slab_alloc_node mm/slub.c:4251 [inline]
 kmem_cache_alloc_noprof+0x1bf/0x410 mm/slub.c:4260
 skb_clone+0x21d/0x470 net/core/skbuff.c:2084
 deliver_clone net/bridge/br_forward.c:125 [inline]
 maybe_deliver net/bridge/br_forward.c:191 [inline]
 br_flood+0x4df/0x720 net/bridge/br_forward.c:237
 br_handle_frame_finish+0x1157/0x1620 net/bridge/br_input.c:215
 nf_hook_bridge_pre net/bridge/br_input.c:301 [inline]
 br_handle_frame+0x5a5/0xba0 net/bridge/br_input.c:424
 __netif_receive_skb_core+0xfc4/0x3a70 net/core/dev.c:5695
 __netif_receive_skb_one_core net/core/dev.c:5799 [inline]
 __netif_receive_skb net/core/dev.c:5914 [inline]
 process_backlog+0x40b/0xaf0 net/core/dev.c:6250
 __napi_poll+0xcd/0x600 net/core/dev.c:6901
 napi_poll net/core/dev.c:6970 [inline]
 net_rx_action+0x5dc/0xd70 net/core/dev.c:7092
 handle_softirqs+0x1ad/0x620 kernel/softirq.c:621
 __do_softirq+0xf/0x16 kernel/softirq.c:659
 do_softirq+0xb8/0x110 kernel/softirq.c:503
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x74/0x80 kernel/softirq.c:430
 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline]
 _raw_spin_unlock_bh+0x54/0x60 kernel/locking/spinlock.c:210
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 addrconf_ifdown+0x60d/0x1970 net/ipv6/addrconf.c:3950
 addrconf_notify+0x17a/0xeb0 net/ipv6/addrconf.c:-1
 notifier_call_chain+0x106/0x2b0 kernel/notifier.c:93
 raw_notifier_call_chain+0x31/0x40 kernel/notifier.c:461
 call_netdevice_notifiers_info net/core/dev.c:2074 [inline]
 call_netdevice_notifiers_extack net/core/dev.c:2112 [inline]
 call_netdevice_notifiers net/core/dev.c:2126 [inline]
 dev_close_many+0x332/0x4f0 net/core/dev.c:1667
 unregister_netdevice_many_notify+0x4bd/0x1be0 net/core/dev.c:11507
 unregister_netdevice_many net/core/dev.c:11595 [inline]
 unregister_netdevice_queue+0x302/0x350 net/core/dev.c:11469
 unregister_netdevice include/linux/netdevice.h:3165 [inline]
 __tun_detach+0xc98/0x1450 drivers/net/tun.c:685
 tun_detach drivers/net/tun.c:701 [inline]
 tun_chr_close+0x93/0x150 drivers/net/tun.c:3520
 __fput+0x208/0xa30 fs/file_table.c:447
 ____fput+0x20/0x30 fs/file_table.c:475
 task_work_run+0x1e8/0x260 kernel/task_work.c:246
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0xa46/0x2850 kernel/exit.c:961
 do_group_exit+0x21f/0x2f0 kernel/exit.c:1104
 get_signal+0x134c/0x1490 kernel/signal.c:2941
 arch_do_signal_or_restart+0xbc/0x700 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x57/0xb0 kernel/entry/common.c:218
 do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f8575d592d7
Code: Unable to access opcode bytes at 0x7f8575d592ad.
RSP: 002b:00007ffd9866b790 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: 0000000000000054 RBX: 000055556493e500 RCX: 00007f8575d592d7
RDX: 0000000000000054 RSI: 00007f8576b54670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffd9866b7f4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f8576b54670 R15: 0000000000000000
 </TASK>
net_ratelimit: 113089 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:82:51:2e:dc:c2:06, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:82:51:2e:dc:c2:06, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:82:51:2e:dc:c2:06, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:82:51:2e:dc:c2:06, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:82:51:2e:dc:c2:06, vlan:0)

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/24 07:29 android16-6.12 a24919af1c4d 0281b448 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in exit_aio
2026/09/16 16:51 android16-6.12 1107981d2d5c 12a0a44a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in exit_aio
2026/09/05 23:11 android16-6.12 4e585dd7f3b7 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in exit_aio
2026/08/15 21:54 android16-6.12 26014f6c6077 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in exit_aio
* Struck through repros no longer work on HEAD.