INFO: task syz.2.179:7271 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.179 state:D stack:26584 pid:7271 tgid:7254 ppid:5798 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x1472/0x4fe0 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760
__rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114
rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
__down_read kernel/locking/rwsem.c:1466 [inline]
down_read+0x132/0x200 kernel/locking/rwsem.c:1539
inode_lock_shared include/linux/fs.h:1042 [inline]
open_last_lookups fs/namei.c:4548 [inline]
path_openat+0xb56/0x3e70 fs/namei.c:4793
do_filp_open+0x22d/0x490 fs/namei.c:4823
do_sys_openat2+0x12f/0x220 fs/open.c:1430
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1447
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbf16ffaeb9
RSP: 002b:00007fbf15235028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fbf17276090 RCX: 00007fbf16ffaeb9
RDX: 0000000000040000 RSI: 0000200000000280 RDI: ffffffffffffff9c
RBP: 00007fbf17068c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000120 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbf17276128 R14: 00007fbf17276090 R15: 00007ffd13ce1e28
INFO: task syz.2.179:7278 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.179 state:D stack:26840 pid:7278 tgid:7254 ppid:5798 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x1472/0x4fe0 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7245
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760
rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244
inode_lock include/linux/fs.h:1027 [inline]
open_last_lookups fs/namei.c:4546 [inline]
path_openat+0xb65/0x3e70 fs/namei.c:4793
do_filp_open+0x22d/0x490 fs/namei.c:4823
do_sys_openat2+0x12f/0x220 fs/open.c:1430
do_sys_open fs/open.c:1436 [inline]
__do_sys_open fs/open.c:1444 [inline]
__se_sys_open fs/open.c:1440 [inline]
__x64_sys_open+0x11e/0x150 fs/open.c:1440
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbf16ffaeb9
RSP: 002b:00007fbf149ce028 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007fbf17276360 RCX: 00007fbf16ffaeb9
RDX: 0000000000000007 RSI: 00000000001cd9c3 RDI: 0000200000000100
RBP: 00007fbf17068c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbf172763f8 R14: 00007fbf17276360 R15: 00007ffd13ce1e28
Showing all locks held in the system:
3 locks held by rcuc/0/20:
1 lock held by khungtaskd/38:
#0: ffffffff8dbc77c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8dbc77c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8dbc77c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:5/86:
3 locks held by kworker/u8:10/1499:
#0: ffff88813fe69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88813fe69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
#1: ffffc9000543fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000543fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
#2: ffffffff8ef3b3b8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
4 locks held by kworker/u8:12/1547:
2 locks held by dhcpcd/5460:
#0: ffff888036ca8928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xe4/0xe80 net/netlink/af_netlink.c:2267
#1: ffffffff8ef3b3b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8ef3b3b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6826
2 locks held by getty/5557:
#0: ffff888035af50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
3 locks held by kworker/u9:4/5812:
#0: ffff8880399b8138 ((wq_completion)hci6){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff8880399b8138 ((wq_completion)hci6){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
#1: ffffc90004ddfbc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90004ddfbc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
#2: ffff88805dd78f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331
3 locks held by syz.2.179/7256:
1 lock held by syz.2.179/7271:
#0: ffff88803e7a9098 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1042 [inline]
#0: ffff88803e7a9098 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: open_last_lookups fs/namei.c:4548 [inline]
#0: ffff88803e7a9098 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: path_openat+0xb56/0x3e70 fs/namei.c:4793
2 locks held by syz.2.179/7278:
#0: ffff888038d32480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff88803e7a9098 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#1: ffff88803e7a9098 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: open_last_lookups fs/namei.c:4546 [inline]
#1: ffff88803e7a9098 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: path_openat+0xb65/0x3e70 fs/namei.c:4793
1 lock held by syz-executor/7425:
#0: ffffffff8ef3b3b8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8ef3b3b8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3436
3 locks held by syz-executor/7511:
1 lock held by syz-executor/8442:
#0: ffffffff8ef3b3b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8ef3b3b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8ef3b3b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071
2 locks held by syz.9.340/8802:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xf90/0xfe0 kernel/hung_task.c:515
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 86 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:146 [inline]
RIP: 0010:lock_acquire+0xd4/0x330 kernel/locking/lockdep.c:5869
Code: 8c 0b 00 00 00 0f 85 aa 00 00 00 4c 89 74 24 10 4d 89 fe 9c 41 5f fa 48 c7 c7 77 41 35 8d e8 d3 99 6e 09 65 ff 05 1c d6 86 10 <45> 31 c9 4c 89 7c 24 08 41 f7 c7 00 02 00 00 41 0f 94 c1 4c 89 ef
RSP: 0018:ffffc9000153f3d8 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 0000000000000000 RSI: ffffffff8d354177 RDI: ffffffff8b85e880
RBP: ffffffff81757165 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc9000153f598 R11: ffffffff81ae5ef0 R12: 0000000000000002
R13: ffffffff8dbc77c0 R14: 0000000000000000 R15: 0000000000000246
FS: 0000000000000000(0000) GS:ffff8881266c9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110f24c32d CR3: 000000000d9b4000 CR4: 00000000003526f0
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xc2/0x23c0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_node_noprof+0x22f/0x6d0 mm/slub.c:5315
__alloc_skb+0x1d7/0x390 net/core/skbuff.c:679
alloc_skb include/linux/skbuff.h:1383 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:818 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:875 [inline]
nsim_dev_trap_report_work+0x29f/0xbc0 drivers/net/netdevsim/dev.c:921
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
worker_thread+0xda6/0x1360 kernel/workqueue.c:3421
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246