INFO: task syz.0.441:8215 blocked for more than 143 seconds.
Tai
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.441 state:D stack:28552 pid:8215 tgid:8213 ppid:5608 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5581 [inline]
__schedule+0x1b47/0x5b40 kernel/sched/core.c:7384
__schedule_loop kernel/sched/core.c:7461 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7476
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7533
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7c4/0x15a0 kernel/locking/mutex.c:821
bdev_open+0xde/0xd70 block/bdev.c:990
blkdev_open+0x461/0x600 block/fops.c:696
do_dentry_open+0x80e/0x1360 fs/open.c:1000
vfs_open_consume+0x4a/0x350 fs/open.c:1131
do_open fs/namei.c:4846 [inline]
path_openat+0x14a6/0x1da0 fs/namei.c:5011
do_file_open+0x23e/0x4a0 fs/namei.c:5040
do_sys_openat2+0x115/0x200 fs/open.c:1442
do_sys_open fs/open.c:1448 [inline]
__do_sys_openat fs/open.c:1464 [inline]
__se_sys_openat fs/open.c:1459 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1459
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3ca9d5e98e
RSP: 002b:00007f3caabf0b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f3caabf16c0 RCX: 00007f3ca9d5e98e
RDX: 0000000000000000 RSI: 00007f3caabf0c00 RDI: ffffffffffffff9c
RBP: 00007f3caabf0c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f3caa026038 R14: 00007f3caa025fa0 R15: 00007ffde88cfe68
Showing all locks held in the system:
locks held by khungtaskd/33: 1, last CPU#1:
#0: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by getty/5365: 2, on CPU#0:
#0: ffff8880357240a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211
locks held by syz-executor/5969: 4, last CPU#0:
#0: ffffffff8ee362f0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1541 [inline]
#0: ffffffff8ee362f0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x10a/0x470 kernel/fork.c:1594
#1: ffff88807a168340 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:548 [inline]
#1: ffff88807a168340 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x195/0x1dc0 mm/mmap.c:1716
#2: ffff88802c1f6540 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:538 [inline]
#2: ffff88802c1f6540 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x221/0x1dc0 mm/mmap.c:1723
#3: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#3: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#3: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:302
locks held by udevd/6739: 1, on CPU#1:
#0: ffff888027187350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990
locks held by syz.0.441/8215: 1, on CPU#1:
#0: ffff888027187350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:990
locks held by syz.7.854/10341: 2, last CPU#0:
#0: ffff8880496ad220 (sk_lock-AF_TIPC){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline]
#0: ffff8880496ad220 (sk_lock-AF_TIPC){+.+.}-{0:0}, at: tipc_wait_for_rcvmsg+0x34f/0x6c0 net/tipc/socket.c:1853
#1: ffff88807f73b440 (&mm->mmap_lock){++++}-{4:4}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffff88807f73b440 (&mm->mmap_lock){++++}-{4:4}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffff88807f73b440 (&mm->mmap_lock){++++}-{4:4}, at: lruvec_stat_mod_folio+0x6e/0x3e0 mm/memcontrol.c:1063
locks held by syz.8.855/10354: 1, last CPU#0:
#0: ffff88802c1f5900 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:586 [inline]
#0: ffff88802c1f5900 (&mm->mmap_lock){++++}-{4:4}, at: __mm_populate+0x182/0x390 mm/gup.c:1946
locks held by syz.4.857/10356: 2, on CPU#0:
#0: ffff88807a7548e0 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nf_tables_valid_genid+0x3e/0x100 net/netfilter/nf_tables_api.c:11540
#1: ffffffff8ed60a28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#1: ffffffff8ed60a28 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2cb/0x760 kernel/rcu/tree_exp.h:966
locks held by syz.4.857/10366: 2, on CPU#0:
#0: ffffffff9aef9dc0 (nfnl_subsys_nftables){+.+.}-{4:4}, at: nfnl_lock net/netfilter/nfnetlink.c:96 [inline]
#0: ffffffff9aef9dc0 (nfnl_subsys_nftables){+.+.}-{4:4}, at: nfnetlink_rcv_batch net/netfilter/nfnetlink.c:392 [inline]
#0: ffffffff9aef9dc0 (nfnl_subsys_nftables){+.+.}-{4:4}, at: nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:647 [inline]
#0: ffffffff9aef9dc0 (nfnl_subsys_nftables){+.+.}-{4:4}, at: nfnetlink_rcv+0x64b/0x28c0 net/netfilter/nfnetlink.c:665
#1: ffff88807a7548e0 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nf_tables_valid_genid+0x3e/0x100 net/netfilter/nf_tables_api.c:11540
locks held by syz.9.858/10368: 4, last CPU#1:
#0: ffff8880593486c8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:309
#1: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: do_fault_around mm/memory.c:5987 [inline]
#1: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: do_read_fault mm/memory.c:6021 [inline]
#1: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: do_fault mm/memory.c:6164 [inline]
#1: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: do_pte_missing+0x139f/0x3570 mm/memory.c:4724
#2: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#2: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#2: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: filemap_map_pages+0x1d1/0x2170 mm/filemap.c:3939
#3: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#3: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#3: ffffffff8ed5a3a0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x240 mm/pgtable-generic.c:302
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 33 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [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:377 [inline]
watchdog+0x1058/0x10d0 kernel/hung_task.c:598
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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: 16 Comm: pr/ttyS0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:425
Code: e8 9e 3d 4f fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 ff 14 c1 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0000:ffffc900001578b8 EFLAGS: 00000002
RAX: 1ffffffff35aa100 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: ffffffff857943b0 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9ad50fc0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124dbd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c401cec CR3: 000000004c790000 CR4: 00000000003526f0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:134 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:156 [inline]
wait_for_lsr+0x184/0x2f0 drivers/tty/serial/8250/8250_port.c:2036
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3294 [inline]
__serial8250_console_fifo_write+0xcd/0x3e0 drivers/tty/serial/8250/8250_port.c:3369
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3402 [inline]
__serial8250_console_write drivers/tty/serial/8250/8250_port.c:3456 [inline]
serial8250_console_write+0xa7e/0x1200 drivers/tty/serial/8250/8250_port.c:3520
nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1
nbcon_emit_one kernel/printk/nbcon.c:1157 [inline]
nbcon_kthread_func+0x6d9/0x8d0 kernel/printk/nbcon.c:1271
kthread+0x38b/0x480 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245