syzbot

INFO: task syz-executor216:4337 blocked for more than 143 seconds.
      Not tainted 6.1.141-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor216 state:D stack:27584 pid:4337  ppid:4294   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
 rwsem_down_read_slowpath+0x4f4/0x840 kernel/locking/rwsem.c:1094
 __down_read_common kernel/locking/rwsem.c:1261 [inline]
 __down_read kernel/locking/rwsem.c:1274 [inline]
 down_read+0x94/0x2d0 kernel/locking/rwsem.c:1522
 iterate_supers+0xa4/0x1d0 fs/super.c:755
 ksys_sync+0x91/0x150 fs/sync.c:102
 __ia32_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f877eba5fa9
RSP: 002b:00007ffc95975e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 0000200000000240 RCX: 00007f877eba5fa9
RDX: 00007f877eba4fd0 RSI: 0000000000000012 RDI: 00007f877ebf2046
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffc95975e90
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f877ec234a8
R13: 00007ffc95975e7c R14: 0000000000000000 R15: 431bde82d7b634db
 </TASK>
INFO: task syz-executor216:4338 blocked for more than 143 seconds.
      Not tainted 6.1.141-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor216 state:D stack:27584 pid:4338  ppid:4292   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
 rwsem_down_read_slowpath+0x4f4/0x840 kernel/locking/rwsem.c:1094
 __down_read_common kernel/locking/rwsem.c:1261 [inline]
 __down_read kernel/locking/rwsem.c:1274 [inline]
 down_read+0x94/0x2d0 kernel/locking/rwsem.c:1522
 iterate_supers+0xa4/0x1d0 fs/super.c:755
 ksys_sync+0x91/0x150 fs/sync.c:102
 __ia32_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f877eba5fa9
RSP: 002b:00007ffc95975e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 0000200000000240 RCX: 00007f877eba5fa9
RDX: 00007f877eba4fd0 RSI: 0000000000000012 RDI: 00007f877ebf2046
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffc95975e90
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f877ec234a8
R13: 00007ffc95975e7c R14: 0000000000000000 R15: 431bde82d7b634db
 </TASK>
INFO: task syz-executor216:4340 blocked for more than 143 seconds.
      Not tainted 6.1.141-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor216 state:D stack:27584 pid:4340  ppid:4293   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
 rwsem_down_read_slowpath+0x4f4/0x840 kernel/locking/rwsem.c:1094
 __down_read_common kernel/locking/rwsem.c:1261 [inline]
 __down_read kernel/locking/rwsem.c:1274 [inline]
 down_read+0x94/0x2d0 kernel/locking/rwsem.c:1522
 iterate_supers+0xa4/0x1d0 fs/super.c:755
 ksys_sync+0x91/0x150 fs/sync.c:102
 __ia32_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f877eba5fa9
RSP: 002b:00007ffc95975e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 0000200000000240 RCX: 00007f877eba5fa9
RDX: 00007f877eba4fd0 RSI: 0000000000000012 RDI: 00007f877ebf2046
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffc95975e90
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f877ec234a8
R13: 00007ffc95975e7c R14: 0000000000000000 R15: 431bde82d7b634db
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8c92b430 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8c92bc50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
 #0: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by kworker/1:1/41:
 #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
 #1: ffffc90000b27d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
2 locks held by getty/4021:
 #0: ffff88814d4fd098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc9000326b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
1 lock held by syz-executor216/4333:
 #0: ffff88802777e0e0 (&type->s_umount_key#66/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x930 fs/super.c:228
1 lock held by syz-executor216/4334:
 #0: ffff88807c30e0e0 (&type->s_umount_key#66/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x930 fs/super.c:228
1 lock held by syz-executor216/4337:
 #0: ffff88807c30e0e0 (&type->s_umount_key#67){.+.+}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755
1 lock held by syz-executor216/4338:
 #0: ffff88807c30e0e0 (&type->s_umount_key#67){.+.+}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755
1 lock held by syz-executor216/4340:
 #0: ffff88807c30e0e0 (&type->s_umount_key#67){.+.+}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755
2 locks held by dhcpcd/4354:
 #0: ffff88806cd7e130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1756 [inline]
 #0: ffff88806cd7e130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xce0 net/packet/af_packet.c:3249
 #1: ffffffff8c930778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
 #1: ffffffff8c930778 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 6.1.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xeee/0xf30 kernel/hung_task.c:377
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 2951 Comm: kworker/u4:5 Not tainted 6.1.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:skb_nfct include/linux/skbuff.h:4588 [inline]
RIP: 0010:skb_release_head_state+0xfd/0x240 net/core/skbuff.c:846
Code: 00 0f 00 0f 85 16 01 00 00 e8 8f 66 6c f9 43 80 3c 27 00 74 08 4c 89 f7 e8 40 df bd f9 48 89 df ff 53 60 eb 05 e8 73 66 6c f9 <4c> 8d 73 68 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8
RSP: 0018:ffffc9000c8b7af0 EFLAGS: 00000293
RAX: ffffffff88146ffd RBX: ffff888073063dc0 RCX: ffff88802eef9dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff1bfd0b6
R10: fffffbfff1bfd0b6 R11: 1ffffffff1bfd0b5 R12: dffffc0000000000
R13: 1ffff1100e60c7c3 R14: ffff888073063e20 R15: 1ffff1100e60c7c4
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055623e813660 CR3: 000000007e4d1000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 skb_release_all net/core/skbuff.c:854 [inline]
 __kfree_skb net/core/skbuff.c:870 [inline]
 consume_skb+0x72/0x100 net/core/skbuff.c:1035
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline]
 nsim_dev_trap_report_work+0x76b/0xaf0 drivers/net/netdevsim/dev.c:851
 process_one_work+0x898/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>