syzbot


INFO: task hung in loop_set_status (3)

Status: auto-obsoleted due to no activity on 2026/04/15 05:34
Subsystems: block
[Documentation on labels]
First crash: 120d, last: 92d
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in loop_set_status (2) block 1 2 272d 312d 0/29 auto-obsoleted due to no activity on 2025/10/17 04:36
upstream INFO: task hung in loop_set_status block 1 109 1609d 1611d 0/29 closed as dup on 2021/11/21 14:00
upstream INFO: task can't die in blk_mq_freeze_queue_wait block 1 221 1606d 1614d 20/29 fixed on 2022/03/08 16:11

Sample crash report:
INFO: task syz.2.37:6902 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.37        state:D stack:0     pid:6902  tgid:6901  ppid:6583   task_flags:0x400040 flags:0x00000011
Call trace:
 __switch_to+0x418/0x87c arch/arm64/kernel/process.c:742 (T)
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x1250/0x2a7c kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0xb4/0x230 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:7017
 __mutex_lock_common+0xd04/0x2678 kernel/locking/mutex.c:692
 __mutex_lock kernel/locking/mutex.c:776 [inline]
 mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:828
 loop_reread_partitions drivers/block/loop.c:447 [inline]
 loop_set_status+0x7bc/0xaf4 drivers/block/loop.c:1277
 loop_set_status64 drivers/block/loop.c:1373 [inline]
 lo_ioctl+0x720/0x177c drivers/block/loop.c:1559
 blkdev_ioctl+0x62c/0xadc block/ioctl.c:792
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __arm64_sys_ioctl+0x14c/0x1c4 fs/ioctl.c:583
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x5c/0x26c arch/arm64/kernel/entry-common.c:724
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:743
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

Showing all locks held in the system:
1 lock held by kthreadd/2:
3 locks held by kworker/u8:0/12:
3 locks held by kworker/u8:1/13:
1 lock held by khungtaskd/32:
 #0: ffff80008fa5b6e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x4/0x48 include/linux/rcupdate.h:330
3 locks held by kworker/u8:2/41:
 #0: ffff0000c0032148 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x63c/0x1558 kernel/workqueue.c:3231
 #1: ffff800097fe7be0 ((crda_timeout).work){+.+.}-{0:0}, at: process_one_work+0x6d0/0x1558 kernel/workqueue.c:3231
 #2: ffff800092ae4928 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:80
5 locks held by pr/ttyAMA-1/43:
3 locks held by kworker/u8:4/183:
3 locks held by kworker/u8:5/290:
 #0: ffff0000c0032148 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x63c/0x1558 kernel/workqueue.c:3231
 #1: ffff800099e87be0 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x6d0/0x1558 kernel/workqueue.c:3231
 #2: ffff800092ae4928 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:80
3 locks held by kworker/u8:6/371:
2 locks held by kworker/u8:7/1328:
3 locks held by kworker/u8:8/1460:
3 locks held by kworker/u8:9/1847:
3 locks held by kworker/u8:10/2192:
7 locks held by kworker/u8:11/2255:
3 locks held by kworker/u8:12/2527:
3 locks held by kworker/u8:13/2981:
3 locks held by kworker/u8:14/3480:
3 locks held by kworker/u8:15/3605:
 #0: ffff0000d5acb948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x63c/0x1558 kernel/workqueue.c:3231
 #1: ffff8000a39d7be0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x6d0/0x1558 kernel/workqueue.c:3231
 #2: ffff800092ae4928 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:80
3 locks held by kworker/u8:16/3888:
3 locks held by kworker/u8:19/5448:
3 locks held by kworker/u8:20/5589:
3 locks held by kworker/u8:21/5832:
3 locks held by kworker/u8:22/6093:
1 lock held by klogd/6201:
2 locks held by udevd/6213:
3 locks held by dhcpcd/6268:
1 lock held by crond/6342:
2 locks held by getty/6354:
 #0: ffff0000c19cd0a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff800099f1e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x34c/0xfc8 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/6560:
2 locks held by udevd/6563:
2 locks held by syz-executor/6571:
6 locks held by kworker/u9:2/6572:
 #0: ffff0000cb126148 ((wq_completion)hci2){+.+.}-{0:0}, at: process_one_work+0x63c/0x1558 kernel/workqueue.c:3231
 #1: ffff8000a20b7be0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x6d0/0x1558 kernel/workqueue.c:3231
 #2: ffff0000d7238ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x184/0x38c net/bluetooth/hci_sync.c:331
 #3: ffff0000d72380c0 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x1d4/0xbb8 net/bluetooth/hci_sync.c:5702
 #4: ffff800092c4fbc8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2128 [inline]
 #4: ffff800092c4fbc8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x13c/0x340 net/bluetooth/hci_conn.c:1336
 #5: ffff0000cb126b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x78/0x53c net/bluetooth/l2cap_core.c:1763
1 lock held by syz-executor/6576:
 #0: ffff800092ae4928 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:80
3 locks held by kworker/0:4/6628:
2 locks held by udevd/6741:
4 locks held by kworker/0:10/6852:
 #0: ffff0000c0029948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x63c/0x1558 kernel/workqueue.c:3231
 #1: ffff8000a1dc7be0 (reg_work){+.+.}-{0:0}, at: process_one_work+0x6d0/0x1558 kernel/workqueue.c:3231
 #2: ffff800092ae4928 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:80
 #3: ffff0000d9478788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6363 [inline]
 #3: ffff0000d9478788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_process_self_managed_hints+0x98/0x1dc net/wireless/reg.c:3179
2 locks held by kworker/0:11/6897:
1 lock held by syz.2.37/6902:
 #0: ffff0000cbbb8358 (&disk->open_mutex){+.+.}-{4:4}, at: loop_reread_partitions drivers/block/loop.c:447 [inline]
 #0: ffff0000cbbb8358 (&disk->open_mutex){+.+.}-{4:4}, at: loop_set_status+0x7bc/0xaf4 drivers/block/loop.c:1277
4 locks held by kworker/1:8/6922:
 #0: ffff0000dfcd0548 ((wq_completion)wg-kex-wg0#2){+.+.}-{0:0}, at: process_one_work+0x63c/0x1558 kernel/workqueue.c:3231
 #1: ffff8000a1807be0 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0x6d0/0x1558 kernel/workqueue.c:3231
 #2: ffff0000c9ca9348 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x130/0x724 drivers/net/wireguard/noise.c:598
 #3: ffff0000ce508338 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x3f0/0x724 drivers/net/wireguard/noise.c:632
4 locks held by kworker/u8:23/6924:
2 locks held by kworker/u8:24/6927:
3 locks held by kworker/u8:25/6928:
2 locks held by syz-executor/6931:
3 locks held by kworker/u8:26/6932:

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Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/15 05:26 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 59e4d31a0470 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in loop_set_status
2025/12/19 01:58 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8f0b4cce4481 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in loop_set_status
* Struck through repros no longer work on HEAD.