INFO: task syz.0.3548:20779 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.0.3548 state:D stack:28808 pid:20779 tgid:20777 ppid:19492 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0xced/0x1b10 kernel/locking/mutex.c:820
device_lock include/linux/device.h:1040 [inline]
usbdev_open+0x1b6/0x870 drivers/usb/core/devio.c:1054
chrdev_open+0x234/0x6a0 fs/char_dev.c:411
do_dentry_open+0x6ab/0x14d0 fs/open.c:947
vfs_open+0x82/0x3f0 fs/open.c:1079
do_open fs/namei.c:4699 [inline]
path_openat+0x208c/0x31a0 fs/namei.c:4858
do_file_open+0x20e/0x430 fs/namei.c:4887
do_sys_openat2+0x10d/0x1e0 fs/open.c:1364
do_sys_open fs/open.c:1370 [inline]
__do_sys_openat fs/open.c:1386 [inline]
__se_sys_openat fs/open.c:1381 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1381
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0f2e55d68e
RSP: 002b:00007f0f2f4f7b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f0f2f4f86c0 RCX: 00007f0f2e55d68e
RDX: 00000000000a0402 RSI: 00007f0f2f4f7c00 RDI: ffffffffffffff9c
RBP: 00007f0f2f4f7c00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd
R13: 00007f0f2e816038 R14: 00007f0f2e815fa0 R15: 00007ffc3346fcf8
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e7e5560 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e7e5560 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e7e5560 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
6 locks held by kworker/0:2/991:
2 locks held by getty/5369:
#0: ffff88803a11e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211
1 lock held by syz.0.3548/20779:
#0: ffff88802b8e71d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#0: ffff88802b8e71d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x1b6/0x870 drivers/usb/core/devio.c:1054
1 lock held by syz.5.3869/22129:
2 locks held by syz.1.3904/22258:
3 locks held by rm/22318:
#0: ffff8880b843b4e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:660 [inline]
#0: ffff8880b843b4e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x88/0x140 kernel/sched/core.c:644
#1: ffff8880b8524648 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:225 [inline]
#1: ffff8880b8524648 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2f15/0x67a0 kernel/sched/core.c:7183
#2: ffffffff9b193e88 (&____s->seqcount#2){----}-{0:0}, at: clockevents_program_event+0x23e/0x820 kernel/time/clockevents.c:363
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 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+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xcb1/0x1030 kernel/hung_task.c:561
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 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: 22258 Comm: syz.1.3904 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:shmem_alloc_and_add_folio+0x550/0xd40 mm/shmem.c:2001
Code: 0f 85 34 06 00 00 e8 df 4b b7 ff 48 63 eb e9 f1 01 00 00 e8 d2 4b b7 ff 48 8b 74 24 28 31 c9 48 89 ef 48 8b 94 24 98 00 00 00 <45> 89 e8 e8 d8 b2 ff ff 31 ff 89 c3 89 c6 e8 5d 46 b7 ff 85 db 0f
RSP: 0018:ffffc90005b5ebc0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000000000488e RSI: ffff88802ce69b58 RDI: ffffea00011aa440
RBP: ffffea00011aa440 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffea00011aa448
R13: 0000000000000cc0 R14: 0000000000000001 R15: 0000000000000000
FS: 00007fc6d7bf66c0(0000) GS:ffff888124487000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561fb0950b11 CR3: 000000008c4ee000 CR4: 00000000003526f0
Call Trace:
shmem_get_folio_gfp+0x6ab/0x1900 mm/shmem.c:2564
shmem_get_folio mm/shmem.c:2670 [inline]
shmem_write_begin+0x1a4/0x420 mm/shmem.c:3303
generic_perform_write+0x292/0xa40 mm/filemap.c:4325
shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3478
__kernel_write_iter+0x2ac/0x920 fs/read_write.c:621
dump_emit_page fs/coredump.c:1304 [inline]
dump_user_range+0x3f9/0xad0 fs/coredump.c:1378
elf_core_dump+0x2d5f/0x3d10 fs/binfmt_elf.c:2109
coredump_write fs/coredump.c:1053 [inline]
do_coredump fs/coredump.c:1132 [inline]
vfs_coredump+0x2980/0x5770 fs/coredump.c:1206
get_signal+0x2162/0x2210 kernel/signal.c:3022
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop kernel/entry/common.c:98 [inline]
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline]
irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline]
irqentry_exit+0x39e/0x970 kernel/entry/common.c:162
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7fc6d999ce61
Code: 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 48 3d 01 f0 ff ff 73 01 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fc6d9c15fa0 RCX: 00007fc6d999ce59
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007fc6d9a32d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fc6d9c16038 R14: 00007fc6d9c15fa0 R15: 00007ffd86c5cec8