syzbot


INFO: task hung in kvm_vm_ioctl_create_vcpu (2)

Status: auto-obsoleted due to no activity on 2025/05/16 03:45
Subsystems: kvm
[Documentation on labels]
First crash: 178d, last: 114d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in kvm_vm_ioctl_create_vcpu kvm 3 356d 383d 0/28 auto-obsoleted due to no activity on 2024/09/16 19:41

Sample crash report:
INFO: task syz.7.3961:32128 blocked for more than 143 seconds.
      Not tainted 6.14.0-rc2-syzkaller-00228-g04f41cbf03ec #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.3961      state:D stack:27552 pid:32128 tgid:32126 ppid:31546  task_flags:0x400040 flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5377 [inline]
 __schedule+0x190e/0x4c90 kernel/sched/core.c:6764
 __schedule_loop kernel/sched/core.c:6841 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6856
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6913
 __mutex_lock_common kernel/locking/mutex.c:662 [inline]
 __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730
 kvm_vm_ioctl_create_vcpu+0x5a/0x8b0 virt/kvm/kvm_main.c:4077
 kvm_vm_ioctl+0x7be/0xd50 virt/kvm/kvm_main.c:5057
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0935f8cde9
RSP: 002b:00007f0936e21038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f09361a6080 RCX: 00007f0935f8cde9
RDX: 0000000000000000 RSI: 000000000000ae41 RDI: 0000000000000004
RBP: 00007f093600e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f09361a6080 R15: 00007f09362cfa28
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746
7 locks held by kworker/u8:5/174:
1 lock held by klogd/5197:
2 locks held by udevd/5208:
2 locks held by dhcpcd/5501:
2 locks held by getty/5593:
 #0: ffff888030dd20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5820:
3 locks held by kworker/0:9/5929:
5 locks held by kworker/1:6/5938:
1 lock held by udevd/22530:
1 lock held by syz-executor/30383:
 #0: ffff88803061a308 (&xt[i].mutex){+.+.}-{4:4}, at: xt_find_target+0x79/0x230 net/netfilter/x_tables.c:254
1 lock held by syz-executor/30577:
 #0: ffff88803061a308 (&xt[i].mutex){+.+.}-{4:4}, at: xt_find_table_lock+0x4c/0x400 net/netfilter/x_tables.c:1243
3 locks held by syz-executor/31350:
3 locks held by syz.7.3961/32127:
1 lock held by syz.7.3961/32128:
 #0: ffffc90005ebdb58 (&kvm->lock){+.+.}-{4:4}, at: kvm_vm_ioctl_create_vcpu+0x5a/0x8b0 virt/kvm/kvm_main.c:4077
3 locks held by kworker/u8:8/32166:
 #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3317
 #1: ffffc90003487c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
 #1: ffffc90003487c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3317
 #2: ffffffff8fed4208 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:285
1 lock held by syz-executor/32173:

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc2-syzkaller-00228-g04f41cbf03ec #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
 watchdog+0x1058/0x10a0 kernel/hung_task.c:399
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 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: 27 Comm: kdevtmpfs Not tainted 6.14.0-rc2-syzkaller-00228-g04f41cbf03ec #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:qlink_to_object mm/kasan/quarantine.c:140 [inline]
RIP: 0010:qlink_free mm/kasan/quarantine.c:145 [inline]
RIP: 0010:qlist_free_all+0x71/0x140 mm/kasan/quarantine.c:179
Code: 4c 05 08 f6 c1 01 0f 85 a8 00 00 00 4c 01 e8 66 90 0f b6 48 33 c1 e1 18 81 f9 00 00 00 f5 48 0f 45 c5 48 8b 58 08 4d 8b 34 24 <48> 63 83 c0 00 00 00 49 29 c4 48 89 df 4c 89 e6 e8 9a e5 ff ff 66
RSP: 0018:ffffc90000a27638 EFLAGS: 00000246
RAX: ffffea0007a6de00 RBX: ffff88801b041dc0 RCX: 00000000f5000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff816eac3c R09: ffffffff8229069f
R10: dffffc0000000000 R11: ffffed10170c8999 R12: ffff8881e9b79800
R13: ffffea0000000000 R14: ffff8881e7efedc0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5019b762d8 CR3: 000000002a856000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000097 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_kmalloc+0x23/0xb0 mm/kasan/common.c:385
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4294 [inline]
 __kmalloc_noprof+0x285/0x4c0 mm/slub.c:4306
 kmalloc_noprof include/linux/slab.h:905 [inline]
 kzalloc_noprof include/linux/slab.h:1037 [inline]
 tomoyo_encode2 security/tomoyo/realpath.c:45 [inline]
 tomoyo_encode+0x26f/0x540 security/tomoyo/realpath.c:80
 tomoyo_realpath_from_path+0x59e/0x5e0 security/tomoyo/realpath.c:283
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x2c0/0x610 security/tomoyo/file.c:822
 security_inode_getattr+0x130/0x330 security/security.c:2377
 vfs_getattr+0x25/0x70 fs/stat.c:243
 handle_remove drivers/base/devtmpfs.c:323 [inline]
 handle drivers/base/devtmpfs.c:386 [inline]
 devtmpfs_work_loop+0x546/0x1040 drivers/base/devtmpfs.c:399
 devtmpfsd+0x4c/0x50 drivers/base/devtmpfs.c:441
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
vkms_vblank_simulate: vblank timer overrun

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/15 03:39 upstream 04f41cbf03ec 40a34ec9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in kvm_vm_ioctl_create_vcpu
2024/12/12 23:49 upstream 150b567e0d57 941924eb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in kvm_vm_ioctl_create_vcpu
* Struck through repros no longer work on HEAD.