INFO: task syz.1.2672:15341 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.2672 state:D stack:27088 pid:15341 ppid:14547 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
sync_bdevs+0x1a4/0x320 block/bdev.c:1077
ksys_sync+0xc6/0x170 fs/sync.c:105
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7efe2079e0d9
RSP: 002b:00007efe2163a028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007efe20a25fa0 RCX: 00007efe2079e0d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007efe20a25fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efe20a26038 R14: 00007efe20a25fa0 R15: 00007ffe1eca9888
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by getty/5533:
#0: ffff88802d3c90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032832f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
2 locks held by kworker/0:4/5820:
#0: ffff888017c72d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#0: ffff888017c72d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
#1: ffffc900048d7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
#1: ffffc900048d7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
2 locks held by kworker/u4:12/5972:
1 lock held by udevd/11448:
#0: ffff888021df34c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801
1 lock held by udevd/11561:
#0: ffff888021db04c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801
1 lock held by udevd/11618:
#0: ffff888021e084c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801
1 lock held by syz.1.2672/15341:
#0: ffff888021e084c8 (&disk->open_mutex){+.+.}-{3:3}, at: sync_bdevs+0x1a4/0x320 block/bdev.c:1077
1 lock held by syz.3.3520/17956:
#0: ffff88805a17cba0 (&sb->s_type->i_mutex_key#25){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff88805a17cba0 (&sb->s_type->i_mutex_key#25){+.+.}-{3:3}, at: fuse_flush+0x2ca/0x8b0 fs/fuse/file.c:533
2 locks held by syz.3.3520/17957:
#0: ffff88801aa88418 (sb_writers#20){.+.+}-{0:0}, at: vfs_write+0x21e/0x9a0 fs/read_write.c:580
#1: ffff88805a17cba0 (&sb->s_type->i_mutex_key#25){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#1: ffff88805a17cba0 (&sb->s_type->i_mutex_key#25){+.+.}-{3:3}, at: fuse_cache_write_iter fs/fuse/file.c:1360 [inline]
#1: ffff88805a17cba0 (&sb->s_type->i_mutex_key#25){+.+.}-{3:3}, at: fuse_file_write_iter+0x2e1/0xf40 fs/fuse/file.c:1694
1 lock held by syz.4.3526/17973:
#0: ffffffff8d137640 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4089
2 locks held by syz.2.3525/17976:
#0: ffffffff8e3d6ac8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline]
#0: ffffffff8e3d6ac8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3514
#1: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#1: ffffffff8d137778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf59/0xfa0 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5129 Comm: klogd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__lock_acquire+0x12c7/0x7d80 kernel/locking/lockdep.c:5134
Code: b6 04 00 84 c0 0f 85 b4 0d 00 00 83 3d 61 a7 c6 15 00 0f 84 16 02 00 00 31 db 48 83 c3 40 48 89 d8 48 c1 e8 03 42 80 3c 00 00 <74> 12 48 89 df e8 0f 58 77 00 49 b8 00 00 00 00 00 fc ff df 48 83
RSP: 0018:ffffc9000327f020 EFLAGS: 00000046
RAX: 1ffffffff216adda RBX: ffffffff90b56ed0 RCX: ffffffff81689cd2
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911ed500
RBP: ffffc9000327f268 R08: dffffc0000000000 R09: 1ffffffff223daa0
R10: dffffc0000000000 R11: fffffbfff223daa1 R12: 0000000058cce5e7
R13: ffff88807d785a00 R14: 00000000c8d5ebdc R15: ffff88807d786508
FS: 00007f2f60e00c80(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f83de7cdff8 CR3: 000000002fddd000 CR4: 00000000003526e0
Call Trace:
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
rcu_read_lock include/linux/rcupdate.h:786 [inline]
is_bpf_text_address+0x47/0x2a0 kernel/bpf/core.c:742
kernel_text_address+0xa0/0xd0 kernel/extable.c:125
__kernel_text_address+0xd/0x30 kernel/extable.c:79
unwind_get_return_address+0x5d/0xc0 arch/x86/kernel/unwind_orc.c:369
arch_stack_walk+0x11d/0x190 arch/x86/kernel/stacktrace.c:26
stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
____kasan_kmalloc mm/kasan/common.c:375 [inline]
__kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384
kasan_kmalloc include/linux/kasan.h:198 [inline]
__do_kmalloc_node mm/slab_common.c:1007 [inline]
__kmalloc_node_track_caller+0xb4/0x230 mm/slab_common.c:1027
kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584
__alloc_skb+0x138/0x2c0 net/core/skbuff.c:653
alloc_skb include/linux/skbuff.h:1316 [inline]
alloc_skb_with_frags+0xcd/0x7a0 net/core/skbuff.c:6353
sock_alloc_send_pskb+0x883/0x9a0 net/core/sock.c:2830
unix_dgram_sendmsg+0x5a9/0x16e0 net/unix/af_unix.c:2003
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg net/socket.c:745 [inline]
__sys_sendto+0x4a9/0x6b0 net/socket.c:2201
__do_sys_sendto net/socket.c:2213 [inline]
__se_sys_sendto net/socket.c:2209 [inline]
__x64_sys_sendto+0xde/0xf0 net/socket.c:2209
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2f60f50407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007fffe352a020 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f2f60e00c80 RCX: 00007f2f60f50407
RDX: 000000000000005e RSI: 00007fffe352a160 RDI: 0000000000000003
RBP: 00007fffe352a590 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007fffe352a5a8
R13: 00007fffe352a160 R14: 0000000000000043 R15: 00007fffe352a160