INFO: task hung in write_versions

Status: upstream: reported on 2026/08/05 03:52
Reported-by: syzbot+b18133a2d3c311efffdf@syzkaller.appspotmail.com
First crash: 50d, last: 11d
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in write_versions 1 7 1h06m 58d 0/3 upstream: reported on 2026/07/27 23:37
upstream INFO: task hung in write_versions prio:low nfs 1 74 1d14h 39d 0/29 upstream: reported on 2026/08/16 09:28
linux-6.6 INFO: task hung in write_versions 1 10 1d19h 58d 0/2 upstream: reported on 2026/07/27 21:30

Sample crash report:
INFO: task syz.1.427:6078 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.427       state:D stack:27824 pid: 6078 ppid:  4192 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xdf5/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:683
 nfsctl_transaction_write+0x105/0x150 fs/nfsd/nfsctl.c:114
 vfs_write+0x304/0xd70 fs/read_write.c:592
 ksys_write+0x153/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7ff0b196e159
RSP: 002b:00007ff0afbc6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ff0b1bf5fa0 RCX: 00007ff0b196e159
RDX: 0000000000000006 RSI: 00002000000001c0 RDI: 0000000000000007
RBP: 00007ff0b1a0503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff0b1bf6038 R14: 00007ff0b1bf5fa0 R15: 00007ffc4d925ed8
 </TASK>
INFO: task syz.1.427:6083 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.427       state:D stack:27888 pid: 6083 ppid:  4192 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xdf5/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:848
 nfsctl_transaction_write+0x105/0x150 fs/nfsd/nfsctl.c:114
 vfs_write+0x304/0xd70 fs/read_write.c:592
 ksys_write+0x153/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7ff0b196e159
RSP: 002b:00007ff0afba5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ff0b1bf6090 RCX: 00007ff0b196e159
RDX: 0000000000000001 RSI: 0000200000000240 RDI: 0000000000000008
RBP: 00007ff0b1a0503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff0b1bf6128 R14: 00007ff0b1bf6090 R15: 00007ffc4d925ed8
 </TASK>
INFO: task syz.8.429:6085 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.429       state:D stack:27888 pid: 6085 ppid:  5226 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xdf5/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:848
 nfsctl_transaction_write+0x105/0x150 fs/nfsd/nfsctl.c:114
 vfs_write+0x304/0xd70 fs/read_write.c:592
 ksys_write+0x153/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fede8e53159
RSP: 002b:00007fede70ab028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fede90dafa0 RCX: 00007fede8e53159
RDX: 0000000000000001 RSI: 0000200000000240 RDI: 0000000000000007
RBP: 00007fede8eea03b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fede90db038 R14: 00007fede90dafa0 R15: 00007ffd7f300338
 </TASK>
INFO: task syz.7.430:6120 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.430       state:D stack:27888 pid: 6120 ppid:  5201 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xdf5/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:683
 nfsctl_transaction_write+0x105/0x150 fs/nfsd/nfsctl.c:114
 vfs_write+0x304/0xd70 fs/read_write.c:592
 ksys_write+0x153/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f145afe5159
RSP: 002b:00007f145923d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f145b26cfa0 RCX: 00007f145afe5159
RDX: 0000000000000006 RSI: 00002000000001c0 RDI: 0000000000000006
RBP: 00007f145b07c03b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f145b26d038 R14: 00007f145b26cfa0 R15: 00007ffcad601e28
 </TASK>
INFO: task syz.7.430:6122 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.430       state:D stack:27888 pid: 6122 ppid:  5201 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xdf5/0x2400 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:848
 nfsctl_transaction_write+0x105/0x150 fs/nfsd/nfsctl.c:114
 vfs_write+0x304/0xd70 fs/read_write.c:592
 ksys_write+0x153/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f145afe5159
RSP: 002b:00007f145921c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f145b26d090 RCX: 00007f145afe5159
RDX: 0000000000000001 RSI: 0000200000000240 RDI: 0000000000000007
RBP: 00007f145b07c03b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f145b26d128 R14: 00007f145b26d090 R15: 00007ffcad601e28
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by kworker/1:2/1324:
 #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc90005037d00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
2 locks held by getty/3949:
 #0: ffff88814d8fa098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
2 locks held by kworker/1:8/4541:
 #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
 #1: ffffc900033e7d00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
3 locks held by syz.2.435/6071:
 #0: ffff888077f900f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff888064a06460 (sb_writers#24){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffffffff8c5717a8 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:848
3 locks held by syz.1.427/6078:
 #0: ffff8880294400f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff88801df20460 (sb_writers#24){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffffffff8c5717a8 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:683
3 locks held by syz.1.427/6083:
 #0: ffff8880294434f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff88801df20460 (sb_writers#24){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffffffff8c5717a8 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:848
3 locks held by syz.8.429/6085:
 #0: ffff88801f570ff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff888064f30460 (sb_writers#24){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffffffff8c5717a8 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:848
3 locks held by syz.7.430/6120:
 #0: ffff88805ff9f270 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff888051832460 (sb_writers#24){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffffffff8c5717a8 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:683
3 locks held by syz.7.430/6122:
 #0: ffff8880771ca0f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff888051832460 (sb_writers#24){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffffffff8c5717a8 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:848
3 locks held by syz.6.434/6820:
 #0: ffff888079358ff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff888022eee460 (sb_writers#24){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffffffff8c5717a8 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:683
3 locks held by syz.6.434/6821:
 #0: ffff888079358af0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff888022eee460 (sb_writers#24){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffffffff8c5717a8 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:848
3 locks held by syz.0.450/6853:
 #0: ffff88804abaf270 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff888050b84460 (sb_writers#24){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffffffff8c5717a8 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:683
3 locks held by syz.0.450/6854:
 #0: ffff88805310c870 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff888050b84460 (sb_writers#24){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffffffff8c5717a8 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:848
3 locks held by syz.4.445/6914:
 #0: ffff888052109c70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff888079ade460 (sb_writers#24){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffffffff8c5717a8 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:683
3 locks held by syz.4.445/6916:
 #0: ffff8880521099f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff888079ade460 (sb_writers#24){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffffffff8c5717a8 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:848
3 locks held by syz.9.451/6949:
 #0: ffff8880760a94f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff888022a30460 (sb_writers#24){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffffffff8c5717a8 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:683
3 locks held by syz.9.451/6951:
 #0: ffff8880798b6af0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff888022a30460 (sb_writers#24){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffffffff8c5717a8 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:848
3 locks held by syz-executor/7729:
 #0: ffff888049b793f0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x5f/0x1020 net/bluetooth/hci_core.c:1755
 #1: ffff888049b78478 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x408/0x1020 net/bluetooth/hci_core.c:1800
 #2: ffffffff8d593488 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1519 [inline]
 #2: ffffffff8d593488 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa4/0x220 net/bluetooth/hci_conn.c:1622
3 locks held by syz.5.465/7954:
 #0: ffff888064f05770 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff8880484f2460 (sb_writers#24){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffffffff8c5717a8 (nfsd_mutex){+.+.}-{3:3}, at: write_versions+0x90/0xbb0 fs/nfsd/nfsctl.c:683
3 locks held by syz.5.465/7959:
 #0: ffff8880259819f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056
 #1: ffff8880484f2460 (sb_writers#24){.+.+}-{0:0}, at: vfs_write+0x296/0xd70 fs/read_write.c:590
 #2: ffffffff8c5717a8 (nfsd_mutex){+.+.}-{3:3}, at: write_ports+0xb3/0xb80 fs/nfsd/nfsctl.c:848
3 locks held by syz-executor/8530:
 #0: ffff88802da353f0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x5f/0x1020 net/bluetooth/hci_core.c:1755
 #1: ffff88802da34478 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x408/0x1020 net/bluetooth/hci_core.c:1800
 #2: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #2: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
4 locks held by syz.3.782/9230:
 #0: ffff88805237d3f0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x5f/0x1020 net/bluetooth/hci_core.c:1755
 #1: ffff88805237c478 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x408/0x1020 net/bluetooth/hci_core.c:1800
 #2: ffffffff8d593488 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1519 [inline]
 #2: ffffffff8d593488 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa4/0x220 net/bluetooth/hci_conn.c:1622
 #3: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 #3: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845
3 locks held by syz-executor/9234:
 #0: ffff8880370953f0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x5f/0x1020 net/bluetooth/hci_core.c:1755
 #1: ffff888037094478 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x408/0x1020 net/bluetooth/hci_core.c:1800
 #2: ffffffff8d593488 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1519 [inline]
 #2: ffffffff8d593488 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa4/0x220 net/bluetooth/hci_conn.c:1622
3 locks held by syz.1.801/9421:
 #0: ffff888049bb93f0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x5f/0x1020 net/bluetooth/hci_core.c:1755
 #1: ffff888049bb8478 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x408/0x1020 net/bluetooth/hci_core.c:1800
 #2: ffffffff8d593488 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1519 [inline]
 #2: ffffffff8d593488 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa4/0x220 net/bluetooth/hci_conn.c:1622
1 lock held by dhcpcd/9481:
 #0: ffff88805227c120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline]
 #0: ffff88805227c120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xd60 net/packet/af_packet.c:3243
1 lock held by dhcpcd/9482:
 #0: ffff888031a76120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline]
 #0: ffff888031a76120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xd60 net/packet/af_packet.c:3243
1 lock held by dhcpcd/9483:
 #0: ffff88803d06a120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline]
 #0: ffff88803d06a120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xd60 net/packet/af_packet.c:3243
1 lock held by dhcpcd/9484:
 #0: ffff88803d6b0120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1744 [inline]
 #0: ffff88803d6b0120 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xd60 net/packet/af_packet.c:3243

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe1b/0xe60 kernel/hung_task.c:369
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9481 Comm: dhcpcd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:preempt_count_add+0xc2/0x190 kernel/sched/core.c:5516
Code: 0b 00 65 4c 8b 35 5e 18 b0 7e 49 81 c6 e8 14 00 00 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 71 e6 6b 00 49 89 1e <5b> 41 5e 41 5f c3 89 fb e8 51 22 93 02 89 df 85 c0 74 9b 48 c7 c0
RSP: 0018:ffffc90003466e10 EFLAGS: 00000202
RAX: 0000000000000003 RBX: ffffc90003466ec8 RCX: ffffffff962f5f03
RDX: dffffc0000000000 RSI: ffffffff87ee89de RDI: 0000000000000001
RBP: 1ffff9200068cde0 R08: ffffc90003466f90 R09: 000000000000000b
R10: dffffc0000000000 R11: fffff5200068cde5 R12: ffffffff87ee89de
R13: ffffc90003467b80 R14: dffffc0000000000 R15: dffffc0000000000
FS:  00007f18f5ef8740(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561a3a02f660 CR3: 00000000444a1000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 unwind_next_frame+0x97/0x1cf0 arch/x86/kernel/unwind_orc.c:433
 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 save_stack+0x121/0x230 mm/page_owner.c:119
 __reset_page_owner+0x51/0x180 mm/page_owner.c:140
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396
 kasan_depopulate_vmalloc_pte+0x67/0x80 mm/kasan/shadow.c:375
 apply_to_pte_range mm/memory.c:2573 [inline]
 apply_to_pmd_range mm/memory.c:2617 [inline]
 apply_to_pud_range mm/memory.c:2653 [inline]
 apply_to_p4d_range mm/memory.c:2689 [inline]
 __apply_to_page_range+0x987/0xd10 mm/memory.c:2725
 kasan_release_vmalloc+0x93/0xb0 mm/kasan/shadow.c:485
 __purge_vmap_area_lazy+0xaf6/0x1940 mm/vmalloc.c:1711
 _vm_unmap_aliases+0x40b/0x4a0 mm/vmalloc.c:2114
 change_page_attr_set_clr+0x317/0xc30 arch/x86/mm/pat/set_memory.c:1740
 change_page_attr_clear arch/x86/mm/pat/set_memory.c:1797 [inline]
 set_memory_x+0xd3/0x110 arch/x86/mm/pat/set_memory.c:1930
 bpf_jit_binary_lock_ro include/linux/filter.h:920 [inline]
 bpf_int_jit_compile+0xbf3f/0xc4d0 arch/x86/net/bpf_jit_comp.c:2478
 bpf_prog_select_runtime+0x46f/0x7b0 kernel/bpf/core.c:1977
 bpf_migrate_filter net/core/filter.c:1307 [inline]
 bpf_prepare_filter+0x100e/0x11b0 net/core/filter.c:1355
 sk_attach_filter+0x20/0x140 net/core/filter.c:1539
 sock_setsockopt+0x18c7/0x2480 net/core/sock.c:1167
 __sys_setsockopt+0x2f6/0x3d0 net/socket.c:2209
 __do_sys_setsockopt net/socket.c:2224 [inline]
 __se_sys_setsockopt net/socket.c:2221 [inline]
 __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2221
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f18f5ffd5aa
Code: 48 83 ec 10 48 63 c9 48 63 ff 45 89 c9 6a 2c e8 8c 4e f8 ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 49 89 ca b8 36 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 8b 15 19 e8 0c 00 f7
RSP: 002b:00007ffd44ba0298 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f18f5ffd5aa
RDX: 000000000000001a RSI: 0000000000000001 RDI: 0000000000000003
RBP: 0000561a39ffc4b0 R08: 0000000000000010 R09: 0000000000000000
R10: 00007ffd44ba02b0 R11: 0000000000000246 R12: 0000000000000000
R13: 0000561a3c6a52a0 R14: 0000000000000000 R15: 0000561a3a011ac0
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/13 06:47 linux-5.15.y 0996e0926f6b 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in write_versions
2026/08/05 03:51 linux-5.15.y 6e2fd6534337 52aa2820 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in write_versions
* Struck through repros no longer work on HEAD.