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: 28d, last: 1d12h
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 446d 511d 0/29 auto-obsoleted due to no activity on 2025/03/13 05:51
android-414 INFO: task hung in exit_aio 1 3 2496d 2496d 0/1 auto-closed as invalid on 2019/10/25 08:40
upstream INFO: task hung in exit_aio (2) fs 1 3 1573d 1651d 0/29 closed as invalid on 2022/02/07 19:09
upstream INFO: task hung in exit_aio (3) fs 1 1 606d 606d 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 111d 253d 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 2390d 3005d 0/29 closed as dup on 2018/04/08 22:50

Sample crash report:
INFO: task syz.4.590:2183 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.590       state:D stack:0     pid:2183  tgid:2176  ppid:449    flags:0x00004004
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: 0033:0x7f302499c797
RSP: 002b:00007f30258360e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f3024c16098 RCX: 00007f302499c799
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f3024c16098
RBP: 00007f3024c16090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3024c16128 R14: 00007ffdd2abc020 R15: 00007ffdd2abc108
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 a88889f1fd4bd040639a1a4060abea1bc20e1fef
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: 33 Comm: rcuop/1 Not tainted syzkaller #0 a88889f1fd4bd040639a1a4060abea1bc20e1fef
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:__is_kernel_text kernel/extable.c:95 [inline]
RIP: 0010:is_kernel_text include/linux/kallsyms.h:29 [inline]
RIP: 0010:core_kernel_text kernel/extable.c:68 [inline]
RIP: 0010:kernel_text_address+0x8/0xe0 kernel/extable.c:99
Code: e9 7d c5 48 04 cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 55 48 89 e5 <41> 57 41 56 53 48 81 ff 00 00 00 81 0f 93 c0 48 81 ff 00 00 e0 85
RSP: 0018:ffffc9000022fa98 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffffff84b99e34 RCX: 000000000022fb01
RDX: ffffc900002302d0 RSI: 1ffff92000045f5e RDI: ffffffff84b99e34
RBP: ffffc9000022fa98 R08: ffffc9000022fbb0 R09: ffffc9000022fba8
R10: 0000000000000007 R11: ffffffff8175cdf0 R12: ffff88810367a600
R13: 0000000000000020 R14: dffffc0000000000 R15: 1ffff92000045f66
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f19ad74aae0 CR3: 000000011e17e000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000400 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 __kernel_text_address+0x11/0x40 kernel/extable.c:79
 unwind_get_return_address+0x51/0x90 arch/x86/kernel/unwind_frame.c:19
 arch_stack_walk+0x10a/0x170 arch/x86/kernel/stacktrace.c:26
 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+0x40/0x50 mm/kasan/generic.c:565
 poison_kmalloc_redzone mm/kasan/common.c:379 [inline]
 __kasan_kmalloc+0x96/0xb0 mm/kasan/common.c:396
 kasan_kmalloc include/linux/kasan.h:261 [inline]
 __kmalloc_cache_noprof+0x23c/0x470 mm/slub.c:4426
 kmalloc_noprof include/linux/slab.h:881 [inline]
 kzalloc_noprof include/linux/slab.h:1017 [inline]
 ref_tracker_alloc+0x184/0x590 lib/ref_tracker.c:203
 __netdev_tracker_alloc include/linux/netdevice.h:4109 [inline]
 netdev_hold include/linux/netdevice.h:4138 [inline]
 dst_init+0xcf/0x420 net/core/dst.c:52
 dst_alloc+0x163/0x250 net/core/dst.c:93
 rt_dst_alloc net/ipv4/route.c:1647 [inline]
 ip_route_input_slow net/ipv4/route.c:2385 [inline]
 ip_route_input_rcu+0x1a0e/0x2700 net/ipv4/route.c:2499
 ip_route_input_noref+0xd4/0x150 net/ipv4/route.c:2510
 arp_process+0x908/0x1790 net/ipv4/arp.c:841
 NF_HOOK+0x17e/0x1e0 include/linux/netfilter.h:317
 arp_rcv+0x2f8/0x490 net/ipv4/arp.c:992
 __netif_receive_skb_one_core net/core/dev.c:5776 [inline]
 __netif_receive_skb net/core/dev.c:5889 [inline]
 netif_receive_skb_internal net/core/dev.c:5975 [inline]
 netif_receive_skb+0x22d/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
 __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
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_do_batch+0x5d9/0xd40 kernel/rcu/tree.c:2594
 nocb_cb_wait kernel/rcu/tree_nocb.h:923 [inline]
 rcu_nocb_cb_kthread+0x524/0xb30 kernel/rcu/tree_nocb.h:957
 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: 3087 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:1c, 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:42:43:18:b6:de:2f, 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:1c, 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:42:43:18:b6:de:2f, 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:1c, vlan:0)
net_ratelimit: 3107 callbacks suppressed
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:1c, 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:42:43:18:b6:de:2f, 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:1c, 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:42:43:18:b6:de:2f, 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:1c, vlan:0)
bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/02 22:20 android16-6.12 a57a57875c30 b9dd6534 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in exit_aio
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.