INFO: task syz.1.134:6464 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.134 state:D stack:22792 pid:6464 tgid:6457 ppid:5847 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5352 [inline]
__schedule+0x1665/0x5590 kernel/sched/core.c:6964
__schedule_loop kernel/sched/core.c:7047 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7062
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7119
rwsem_down_write_slowpath+0x883/0x1080 kernel/locking/rwsem.c:1215
__down_write_common kernel/locking/rwsem.c:1347 [inline]
__down_write kernel/locking/rwsem.c:1356 [inline]
down_write+0x1bc/0x200 kernel/locking/rwsem.c:1626
mmap_write_lock include/linux/mmap_lock.h:536 [inline]
collapse_huge_page mm/khugepaged.c:1153 [inline]
collapse_scan_pmd mm/khugepaged.c:1417 [inline]
collapse_single_pmd+0x24ff/0x4510 mm/khugepaged.c:2427
madvise_collapse+0x34c/0x820 mm/khugepaged.c:2859
madvise_vma_behavior+0x1094/0x4460 mm/madvise.c:1362
madvise_walk_vmas+0x573/0xae0 mm/madvise.c:1711
madvise_do_behavior+0x386/0x540 mm/madvise.c:1927
do_madvise+0x1fa/0x2e0 mm/madvise.c:2020
__do_sys_madvise mm/madvise.c:2029 [inline]
__se_sys_madvise mm/madvise.c:2027 [inline]
__x64_sys_madvise+0xa6/0xc0 mm/madvise.c:2027
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4acad9c799
RSP: 002b:00007f4acbbe8028 EFLAGS: 00000246 ORIG_RAX: 000000000000001c
RAX: ffffffffffffffda RBX: 00007f4acb016180 RCX: 00007f4acad9c799
RDX: 0000000000000019 RSI: 0000000000600722 RDI: 0000200000000000
RBP: 00007f4acae32c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4acb016218 R14: 00007f4acb016180 R15: 00007ffd42e1fd68
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e75d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e75d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e75d6a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by khugepaged/37:
1 lock held by udevd/5211:
2 locks held by getty/5599:
#0: ffff8880331080a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by syz.1.134/6464:
#0: ffff888030938338 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:536 [inline]
#0: ffff888030938338 (&mm->mmap_lock){++++}-{4:4}, at: collapse_huge_page mm/khugepaged.c:1153 [inline]
#0: ffff888030938338 (&mm->mmap_lock){++++}-{4:4}, at: collapse_scan_pmd mm/khugepaged.c:1417 [inline]
#0: ffff888030938338 (&mm->mmap_lock){++++}-{4:4}, at: collapse_single_pmd+0x24ff/0x4510 mm/khugepaged.c:2427
4 locks held by syz.4.706/8361:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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:162 [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:353 [inline]
watchdog+0x1002/0x1060 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6610 Comm: kworker/u8:9 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:385
Code: c0 75 4c 83 3b 00 74 3a 48 83 c3 48 49 89 df 49 c1 ef 03 43 80 3c 37 00 74 08 48 89 df e8 9b e2 b8 00 48 8b 3b e8 23 92 19 00 <85> c0 74 14 43 80 3c 37 00 74 08 48 89 df e8 80 e2 b8 00 48 8b 03
RSP: 0018:ffffc900073675c8 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffc90007367630 RCX: 0000000080000000
RDX: 0000000000000001 RSI: ffffffff8e1ae6f2 RDI: ffffffff822ffaac
RBP: ffffc90007367670 R08: ffffc90007367950 R09: 0000000000000000
R10: ffffc90007367638 R11: fffff52000e6cec9 R12: ffff88801fbd0000
R13: 00000000000000f0 R14: dffffc0000000000 R15: 1ffff92000e6cec6
FS: 0000000000000000(0000) GS:ffff888125535000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000203030 CR3: 00000000578f0000 CR4: 00000000003526f0
Call Trace:
arch_stack_walk+0xfb/0x150 arch/x86/kernel/stacktrace.c:26
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:4569 [inline]
slab_alloc_node mm/slub.c:4898 [inline]
kmem_cache_alloc_node_noprof+0x384/0x690 mm/slub.c:4950
__alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:702
alloc_skb include/linux/skbuff.h:1383 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline]
nsim_dev_trap_report_work+0x29a/0xb80 drivers/net/netdevsim/dev.c:922
process_one_work+0x9ab/0x1780 kernel/workqueue.c:3289
process_scheduled_works kernel/workqueue.c:3380 [inline]
worker_thread+0xba8/0x11e0 kernel/workqueue.c:3466
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245