syzbot

INFO: task udevd:4174 blocked for more than 144 seconds.
      Not tainted 5.15.189-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:26184 pid: 4174 ppid:  3561 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518
 __mutex_lock_common+0xc71/0x2390 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 device_lock include/linux/device.h:760 [inline]
 uevent_show+0x17a/0x330 drivers/base/core.c:2408
 dev_attr_show+0x50/0xb0 drivers/base/core.c:2110
 sysfs_kf_seq_show+0x316/0x4c0 fs/sysfs/file.c:61
 seq_read_iter+0x49b/0xd50 fs/seq_file.c:230
 call_read_iter include/linux/fs.h:2166 [inline]
 new_sync_read fs/read_write.c:404 [inline]
 vfs_read+0x725/0xcf0 fs/read_write.c:485
 ksys_read+0x14d/0x250 fs/read_write.c:623
 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: 0033:0x7f5353566407
RSP: 002b:00007fff842b4f10 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f5353478880 RCX: 00007f5353566407
RDX: 0000000000001000 RSI: 000055c4f16e8950 RDI: 0000000000000008
RBP: 00007f53536aeff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a
R13: 00007f53536aeea0 R14: 0000000000000000 R15: 000055c4f16e0f30
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c11c360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3956:
 #0: ffff88807e508098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
4 locks held by udevd/4174:
 #0: ffff88802949b418 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182
 #1: ffff88801b962488 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x51/0x3c0 fs/kernfs/file.c:112
 #2: ffff88805c29bda0 (kn->active#32){++++}-{0:0}, at: kernfs_seq_start+0x71/0x3c0 fs/kernfs/file.c:113
 #3: ffff88802af84220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
 #3: ffff88802af84220 (&dev->mutex){....}-{3:3}, at: uevent_show+0x17a/0x330 drivers/base/core.c:2408
6 locks held by kworker/1:5/4248:
 #0: ffff8880177f7938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000323fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: ffff88814840b220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
 #2: ffff88814840b220 (&dev->mutex){....}-{3:3}, at: hub_event+0x18f/0x4fa0 drivers/usb/core/hub.c:5781
 #3: ffff88802af84220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
 #3: ffff88802af84220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:954
 #4: ffff88807c0941a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
 #4: ffff88807c0941a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:954
 #5: ffffffff8bfccbf0 (umhelper_sem){++++}-{3:3}, at: usermodehelper_read_trylock+0xe7/0x320 kernel/umh.c:217
2 locks held by kworker/1:7/4296:
 #0: ffff888016872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000334fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
5 locks held by kworker/u4:11/4485:
 #0: ffff8880169cd938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000450fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: ffffffff8d22a2d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:589
 #3: ffffffff8d235f48 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock_unregistering net/core/dev.c:11620 [inline]
 #3: ffffffff8d235f48 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0x149/0x390 net/core/dev.c:11658
 #4: ffffffff8c120de8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 #4: ffffffff8c120de8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x320/0x6b0 kernel/rcu/tree_exp.h:845
1 lock held by syz.3.50/4497:
 #0: ffff88814840b220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
 #0: ffff88814840b220 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x16b/0x790 drivers/usb/core/devio.c:1040
2 locks held by udevd/5138:
 #0: ffff88805fd60118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915
 #1: ffff88801f51b468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2071
1 lock held by syz.1.503/6082:
 #0: ffff88814840b220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
 #0: ffff88814840b220 (&dev->mutex){....}-{3:3}, at: usbdev_open+0x16b/0x790 drivers/usb/core/devio.c:1040
3 locks held by syz.5.530/6161:
 #0: ffff88807a940ff0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x5f/0x1030 net/bluetooth/hci_core.c:1737
 #1: ffff88807a940078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x3f4/0x1030 net/bluetooth/hci_core.c:1782
 #2: ffffffff8d37c328 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1517 [inline]
 #2: ffffffff8d37c328 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa4/0x220 net/bluetooth/hci_conn.c:1622
5 locks held by syz-executor/6165:
 #0: ffffffff8d22a2d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:499
 #1: ffffffff8d017890 (devices_rwsem){++++}-{3:3}, at: rdma_dev_init_net+0x165/0x240 drivers/infiniband/core/device.c:1187
 #2: ffffffff8d017a50 (rdma_nets_rwsem){++++}-{3:3}, at: rdma_dev_init_net+0x19d/0x240 drivers/infiniband/core/device.c:1192
 #3: ffff888076448fe8 (&device->compat_devs_mutex){+.+.}-{3:3}, at: add_one_compat_dev+0xee/0x590 drivers/infiniband/core/device.c:951
 #4: ffffffff8d235f48 (rtnl_mutex){+.+.}-{3:3}, at: ib_get_eth_speed+0x149/0x4b0 drivers/infiniband/core/verbs.c:1905
1 lock held by syz.0.531/6173:
 #0: ffffffff8c120de8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #0: ffffffff8c120de8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 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+0xe0f/0xe50 kernel/hung_task.c:369
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5138 Comm: udevd Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:check_kcov_mode kernel/kcov.c:172 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x13/0x60 kernel/kcov.c:206
Code: 48 8b 3d c0 ac f1 0b 48 89 de 5b e9 77 99 43 00 00 00 cc cc 00 00 cc 48 8b 04 24 65 48 8b 0d 94 ab 8a 7e 65 8b 15 95 ab 8a 7e <81> e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00
RSP: 0018:ffffc900045ef970 EFLAGS: 00000293
RAX: ffffffff813565d5 RBX: 000000005912e200 RCX: ffff888027631dc0
RDX: 0000000080000000 RSI: 000000000000002e RDI: 0000000000000040
RBP: 0000000000000000 R08: ffff88805b698480 R09: 000000000020000d
R10: fffffbfff1ad2dd6 R11: 1ffffffff1ad2dd5 R12: ffffc900045ef9f8
R13: 0000000000000001 R14: 000000000000002e R15: ffff888016841780
FS:  00007f5353478880(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5352b21000 CR3: 0000000054812000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 phys_addr_valid arch/x86/mm/physaddr.h:7 [inline]
 __phys_addr+0x95/0x170 arch/x86/mm/physaddr.c:28
 virt_to_head_page include/linux/mm.h:900 [inline]
 memcg_slab_free_hook+0x89/0x1f0 mm/slab.h:348
 do_slab_free mm/slub.c:3432 [inline]
 ___cache_free+0x63/0x120 mm/slub.c:3506
 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3220 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0x100/0x290 mm/slub.c:3233
 getname_flags+0xb5/0x500 fs/namei.c:138
 do_sys_openat2+0xcf/0x4a0 fs/open.c:1247
 do_sys_open fs/open.c:1269 [inline]
 __do_sys_openat fs/open.c:1285 [inline]
 __se_sys_openat fs/open.c:1280 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1280
 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: 0033:0x7f53535d4c3a
Code: 41 89 f2 48 89 54 24 e0 41 83 e2 40 75 2a 89 f0 f7 d0 a9 00 00 41 00 74 1f 89 f2 b8 01 01 00 00 48 89 fe bf 9c ff ff ff 0f 05 <48> 3d 00 f0 ff ff 77 2e c3 0f 1f 44 00 00 48 8d 44 24 08 c7 44 24
RSP: 002b:00007fff842bbff8 EFLAGS: 00000206 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fff842bc030 RCX: 00007f53535d4c3a
RDX: 0000000000090800 RSI: 00007fff842bc430 RDI: 00000000ffffff9c
RBP: 0000000000000007 R08: 000055c4f16d87b0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 000055c4f1763440
R13: 00007fff842bcc30 R14: 00007fff842bc830 R15: 00007fff842bc430
 </TASK>