INFO: task syz.6.3251:18416 blocked for more than 143 seconds.
      Not tainted 6.14.0-rc3-syzkaller-00267-gff202c5028a1 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.3251      state:D stack:23736 pid:18416 tgid:18415 ppid:8138   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0x190e/0x4c90 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6857
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914
 __mutex_lock_common kernel/locking/mutex.c:662 [inline]
 __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730
 sync_bdevs+0x1ae/0x340 block/bdev.c:1246
 ksys_sync+0xe2/0x1c0 fs/sync.c:105
 __do_sys_sync+0xe/0x20 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6d4bd8d169
RSP: 002b:00007f6d4cbb3038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f6d4bfa5fa0 RCX: 00007f6d4bd8d169
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f6d4bfa5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f6d4bfa5fa0 R15: 00007ffe2a3da4c8
 </TASK>
INFO: task syz.6.3251:18418 blocked for more than 144 seconds.
      Not tainted 6.14.0-rc3-syzkaller-00267-gff202c5028a1 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.3251      state:D stack:27296 pid:18418 tgid:18415 ppid:8138   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0x190e/0x4c90 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6857
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914
 __mutex_lock_common kernel/locking/mutex.c:662 [inline]
 __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730
 sync_bdevs+0x1ae/0x340 block/bdev.c:1246
 ksys_sync+0xe2/0x1c0 fs/sync.c:105
 __do_sys_sync+0xe/0x20 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6d4bd8d169
RSP: 002b:00007f6d4cb92038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f6d4bfa6080 RCX: 00007f6d4bd8d169
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f6d4bfa6080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f6d4bfa6080 R15: 00007ffe2a3da4c8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8eb38f60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746
2 locks held by getty/5588:
 #0: ffff888031bed0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211
1 lock held by udevd/10334:
 #0: ffff888025edf4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:903
1 lock held by syz.6.3251/18416:
 #0: ffff888025edf4c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ae/0x340 block/bdev.c:1246
1 lock held by syz.6.3251/18418:
 #0: ffff888025edf4c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x1ae/0x340 block/bdev.c:1246
1 lock held by syz.7.3718/20097:

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc3-syzkaller-00267-gff202c5028a1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
 watchdog+0x1058/0x10a0 kernel/hung_task.c:399
 kthread+0x7ab/0x920 kernel/kthread.c:464
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5185 Comm: syslogd Not tainted 6.14.0-rc3-syzkaller-00267-gff202c5028a1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:unwind_next_frame+0xc5/0x22d0 arch/x86/kernel/unwind_orc.c:482
Code: 8c 24 90 00 00 00 48 89 5c 24 20 bf 01 00 00 00 e8 10 4b 22 00 49 8d 6d 50 48 89 e8 48 c1 e8 03 48 89 44 24 38 42 80 3c 20 00 <74> 08 48 89 ef e8 31 df bb 00 48 8b 5d 00 48 85 db 74 24 48 81 c3
RSP: 0018:ffffc900033c73d0 EFLAGS: 00000246
RAX: 1ffff92000678e9e RBX: 1ffff92000678e94 RCX: ffffffff8c0b4900
RDX: dffffc0000000000 RSI: ffffffff8228ed70 RDI: ffffffff816d1530
RBP: ffffc900033c74f0 R08: 0000000000000001 R09: ffffc900033c7590
R10: dffffc0000000000 R11: ffffffff81ad4640 R12: dffffc0000000000
R13: ffffc900033c74a0 R14: ffffffff8228ed70 R15: 0000000000000000
FS:  00007fc89bc81380(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8432b79178 CR3: 0000000035a3a000 CR4: 0000000000350ef0
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4609 [inline]
 kfree+0x196/0x430 mm/slub.c:4757
 skb_kfree_head net/core/skbuff.c:996 [inline]
 skb_free_head net/core/skbuff.c:1008 [inline]
 skb_release_data+0x6a0/0x8a0 net/core/skbuff.c:1035
 skb_release_all net/core/skbuff.c:1100 [inline]
 __kfree_skb net/core/skbuff.c:1114 [inline]
 consume_skb+0x9f/0xf0 net/core/skbuff.c:1346
 __unix_dgram_recvmsg+0xcf5/0x1320 net/unix/af_unix.c:2514
 sock_recvmsg_nosec net/socket.c:1023 [inline]
 sock_recvmsg+0x231/0x280 net/socket.c:1045
 sock_read_iter+0x2c4/0x3d0 net/socket.c:1115
 new_sync_read fs/read_write.c:484 [inline]
 vfs_read+0x977/0xb40 fs/read_write.c:565
 ksys_read+0x18f/0x2b0 fs/read_write.c:708
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc89bdd5b6a
Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffc2f691b38 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fc89bdd5b6a
RDX: 00000000000000ff RSI: 0000555e40ca5950 RDI: 0000000000000000
RBP: 0000555e40ca5910 R08: 0000000000000001 R09: 0000000000000000
R10: 00007fc89bf743a3 R11: 0000000000000246 R12: 0000555e40ca5989
R13: 0000555e40ca5950 R14: 0000000000000000 R15: 00007fc89bfb8a80
 </TASK>