INFO: task syz.2.2367:14436 blocked for more than 143 seconds.
Not tainted 6.16.0-rc6-next-20250718-syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.2367 state:D stack:26920 pid:14436 tgid:14436 ppid:13888 task_flags:0x40044c flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5351 [inline]
__schedule+0x1737/0x4d30 kernel/sched/core.c:6954
__schedule_loop kernel/sched/core.c:7036 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7051
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7108
rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1088
__down_read_common kernel/locking/rwsem.c:1263 [inline]
__down_read kernel/locking/rwsem.c:1276 [inline]
down_read+0x98/0x2e0 kernel/locking/rwsem.c:1541
mmap_read_lock include/linux/mmap_lock.h:412 [inline]
exit_mm+0xcc/0x2c0 kernel/exit.c:557
do_exit+0x648/0x2300 kernel/exit.c:947
do_group_exit+0x21c/0x2d0 kernel/exit.c:1100
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:208 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fab8558e9e3
RSP: 002b:00007ffe853f4fc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: fffffffffffffffc RBX: 00007fab83bf76c0 RCX: 00007fab8558e9e3
RDX: 0000000000000000 RSI: 0000000000021000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000020022 R11: 0000000000000246 R12: 00007ffe853f5120
R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e53d8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by kworker/u8:5/62:
#0: ffff8880b8739f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636
#1: ffff8880b8724008 (per_cpu_ptr(&psi_seq, cpu)){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:937
2 locks held by getty/5617:
#0: ffff888033e330a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036c32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by kworker/0:3/5917:
1 lock held by udevd/6105:
#0: ffff8880b8739f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636
1 lock held by syz.2.2367/14436:
#0: ffff88806a481760 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:412 [inline]
#0: ffff88806a481760 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0xcc/0x2c0 kernel/exit.c:557
1 lock held by syz.2.2367/14437:
2 locks held by syz.6.2992/17323:
2 locks held by syz.6.3009/17379:
#0: ffffffff9a4490b8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:98 [inline]
#0: ffffffff9a4490b8 (nfnl_subsys_ipset){+.+.}-{4:4}, at: nfnetlink_rcv_msg+0x9dc/0x1130 net/netfilter/nfnetlink.c:295
#1: ffffffff8e543338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#1: ffffffff8e543338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:967
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf93/0xfe0 kernel/hung_task.c:491
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
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: 17323 Comm: syz.6.2992 Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:clear_page_erms+0xb/0x20 arch/x86/lib/clear_page_64.S:52
Code: 48 8d 7f 40 75 d9 90 e9 53 1c 04 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa b9 00 10 00 00 31 c0 aa c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000aa8e430 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000001000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888040ee9000
RBP: 1ffffffff1bd168f R08: ffffffff8fe3cf37 R09: 0000000000000000
R10: ffffed10081dd200 R11: fffffbfff1fc79e7 R12: fffa800040ee9000
R13: fffa800000000000 R14: 1ffffffff1bd168d R15: 0000000000000001
FS: 00007f2b017f66c0(0000) GS:ffff8881258ab000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c401360 CR3: 0000000062768000 CR4: 00000000003526f0
DR0: 000000000000004b DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
clear_page arch/x86/include/asm/page_64.h:54 [inline]
clear_highpage_kasan_tagged include/linux/highmem.h:248 [inline]
kernel_init_pages mm/page_alloc.c:1228 [inline]
post_alloc_hook+0x1bd/0x2a0 mm/page_alloc.c:1849
prep_new_page mm/page_alloc.c:1859 [inline]
get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2435
shmem_alloc_folio mm/shmem.c:1871 [inline]
shmem_alloc_and_add_folio+0x447/0xf60 mm/shmem.c:1910
shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2550
shmem_get_folio mm/shmem.c:2656 [inline]
shmem_write_begin+0xf7/0x2b0 mm/shmem.c:3306
generic_perform_write+0x2c5/0x900 mm/filemap.c:4187
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3481
__kernel_write_iter+0x393/0x860 fs/read_write.c:619
dump_emit_page fs/coredump.c:1295 [inline]
dump_user_range+0x8a0/0xc90 fs/coredump.c:1369
elf_core_dump+0x3378/0x3990 fs/binfmt_elf.c:2085
coredump_write+0x1169/0x1900 fs/coredump.c:1048
vfs_coredump+0x1a4b/0x2ab0 fs/coredump.c:1167
get_signal+0x1109/0x1340 kernel/signal.c:3019
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:40 [inline]
exit_to_user_mode_prepare include/linux/irq-entry-common.h:208 [inline]
irqentry_exit_to_user_mode+0x81/0x120 kernel/entry/common.c:73
exc_page_fault+0x9f/0xf0 arch/x86/mm/fault.c:1535
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0xf
Code: Unable to access opcode bytes at 0xffffffffffffffe5.
RSP: 002b:0000200000000058 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f2b03bb5fa0 RCX: 00007f2b0398e9a9
RDX: 0000200000000080 RSI: 0000200000000050 RDI: 0000000000808600
RBP: 00007f2b03a10d69 R08: 0000200000000100 R09: 0000200000000100
R10: 00002000000000c0 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f2b03bb5fa0 R15: 00007ffff2b5a708