syzbot


INFO: task hung in exit_aio (2)

Status: premoderation: reported on 2026/02/04 00:47
Reported-by: syzbot+7aa30bcce7ee9473996d@syzkaller.appspotmail.com
First crash: 25d, last: 12h40m
Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in exit_aio (4) fs 1 6 443d 509d 0/29 auto-obsoleted due to no activity on 2025/03/13 05:51
android-414 INFO: task hung in exit_aio 1 3 2493d 2494d 0/1 auto-closed as invalid on 2019/10/25 08:40
upstream INFO: task hung in exit_aio (2) fs 1 3 1570d 1648d 0/29 closed as invalid on 2022/02/07 19:09
upstream INFO: task hung in exit_aio (3) fs 1 1 603d 603d 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 109d 251d 0/1 auto-obsoleted due to no activity on 2026/01/04 12:01
upstream INFO: task hung in exit_aio fs 1 C 17519 2388d 3003d 0/29 closed as dup on 2018/04/08 22:50

Sample crash report:
INFO: task syz.1.895:3072 blocked for more than 124 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.895       state:D stack:0     pid:3072  tgid:3070  ppid:291    flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6016 [inline]
 __schedule+0x134f/0x1ea0 kernel/sched/core.c:7864
 __schedule_loop kernel/sched/core.c:7945 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7960
 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+0x369/0x650 kernel/sched/completion.c:127
 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
 exit_aio+0x2ec/0x3c0 fs/aio.c:927
 __mmput+0x30/0x320 kernel/fork.c:1350
 mmput+0x55/0x170 kernel/fork.c:1376
 exit_mm kernel/exit.c:574 [inline]
 do_exit+0x93f/0x2650 kernel/exit.c:940
 do_group_exit+0x229/0x2f0 kernel/exit.c:1095
 get_signal+0x1398/0x14e0 kernel/signal.c:2933
 arch_do_signal_or_restart+0xbc/0x760 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: 0033:0x7f0958d9c799
RSP: 002b:00007f0959bad0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f0959016098 RCX: 00007f0958d9c799
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f0959016098
RBP: 00007f0959016090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0959016128 R14: 00007ffef4fc5f60 R15: 00007ffef4fc6048
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 c4f231820317ff22bb61fe038e0df9024df7047c
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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:113
 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline]
 watchdog+0xdad/0xf00 kernel/hung_task.c:423
 kthread+0x2c9/0x370 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: ksoftirqd/1 Not tainted syzkaller #0 c4f231820317ff22bb61fe038e0df9024df7047c
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x32/0x70 kernel/kcov.c:217
Code: 48 8b 45 08 65 48 8b 0d cc 4b 7d 7e 65 8b 15 cd 4b 7d 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 ec 0b 00 00 00 <74> 2c 8b 91 c8 0b 00 00 83 fa 02 75 21 48 8b 91 d0 0b 00 00 48 8b
RSP: 0018:ffffc900001f71f0 EFLAGS: 00000246
RAX: ffffffff847e66db RBX: ffff8881047340d0 RCX: ffff88810367cc00
RDX: 0000000000000100 RSI: 000000000000dd86 RDI: 000000000000dd86
RBP: ffffc900001f71f0 R08: ffff88810367cc00 R09: 0000000000000002
R10: 000000000000a888 R11: 0000000000000100 R12: 0000000000000001
R13: ffffffff87ecd6c8 R14: ffff8881047340d0 R15: ffffffff87ec31e0
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f914edf84c0 CR3: 00000001754e8000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: fffffffffffffffc DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 deliver_ptype_list_skb net/core/dev.c:2328 [inline]
 __netif_receive_skb_core+0x32cb/0x3ab0 net/core/dev.c:5732
 __netif_receive_skb_one_core net/core/dev.c:5774 [inline]
 __netif_receive_skb net/core/dev.c:5889 [inline]
 netif_receive_skb_internal net/core/dev.c:5975 [inline]
 netif_receive_skb+0xe0/0x7b0 net/core/dev.c:6034
 br_netif_receive_skb net/bridge/br_input.c:30 [inline]
 NF_HOOK include/linux/netfilter.h:317 [inline]
 br_pass_frame_up+0x126/0x1b0 net/bridge/br_input.c:70
 br_handle_frame_finish+0x1317/0x1760 net/bridge/br_input.c:221
 nf_hook_bridge_pre net/bridge/br_input.c:301 [inline]
 br_handle_frame+0x5a6/0xba0 net/bridge/br_input.c:424
 __netif_receive_skb_core+0xfae/0x3ab0 net/core/dev.c:5670
 __netif_receive_skb_one_core net/core/dev.c:5774 [inline]
 __netif_receive_skb net/core/dev.c:5889 [inline]
 process_backlog+0x3e5/0xad0 net/core/dev.c:6225
 __napi_poll+0xd0/0x610 net/core/dev.c:6876
 napi_poll net/core/dev.c:6945 [inline]
 net_rx_action+0x5ea/0xd80 net/core/dev.c:7067
 handle_softirqs+0x1aa/0x630 kernel/softirq.c:621
 run_ksoftirqd+0x20/0x30 kernel/softirq.c:999
 smpboot_thread_fn+0x48f/0x8b0 kernel/smpboot.c:164
 kthread+0x2c9/0x370 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>
net_ratelimit: 92856 callbacks suppressed
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 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)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:d6:a7:18:ae:0c:48, vlan:0)
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)
bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
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 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)

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/01 06:42 android16-6.12 7de305bfa436 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in exit_aio
2026/02/22 06:26 android16-6.12 7712ca595283 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in exit_aio
2026/02/08 01:49 android16-6.12 6aeca23b5dee 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in exit_aio
2026/02/04 00:46 android16-6.12 a456898cc65b 42b01fab .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.