INFO: task syz.0.1829:10951 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1829      state:D stack:20112 pid:10951 ppid:5796   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
 rwsem_down_write_slowpath+0xbd2/0xfa0 kernel/locking/rwsem.c:1178
 __down_write_common kernel/locking/rwsem.c:1306 [inline]
 __down_write kernel/locking/rwsem.c:1315 [inline]
 down_write+0x1a7/0x1f0 kernel/locking/rwsem.c:1574
 mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 exit_mmap+0x245/0xb50 mm/mmap.c:3310
 __mmput+0x118/0x3c0 kernel/fork.c:1355
 exit_mm+0x1da/0x2c0 kernel/exit.c:569
 do_exit+0x88e/0x23c0 kernel/exit.c:870
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
 get_signal+0x12fc/0x1400 kernel/signal.c:2902
 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f50ab98f749
RSP: 002b:00007f50ac8c70e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f50abbe5fa8 RCX: 00007f50ab98f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f50abbe5fa8
RBP: 00007f50abbe5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f50abbe6038 R14: 00007ffe70a5a690 R15: 00007ffe70a5a778
 </TASK>
INFO: task syz.3.1830:10956 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1830      state:D stack:22472 pid:10956 ppid:5793   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
 rwsem_down_write_slowpath+0xbd2/0xfa0 kernel/locking/rwsem.c:1178
 __down_write_common kernel/locking/rwsem.c:1306 [inline]
 __down_write kernel/locking/rwsem.c:1315 [inline]
 down_write+0x1a7/0x1f0 kernel/locking/rwsem.c:1574
 mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 exit_mmap+0x245/0xb50 mm/mmap.c:3310
 __mmput+0x118/0x3c0 kernel/fork.c:1355
 exit_mm+0x1da/0x2c0 kernel/exit.c:569
 do_exit+0x88e/0x23c0 kernel/exit.c:870
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
 get_signal+0x12fc/0x1400 kernel/signal.c:2902
 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fcef098f749
RSP: 002b:00007fcef18b10e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fcef0be5fa8 RCX: 00007fcef098f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fcef0be5fa8
RBP: 00007fcef0be5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcef0be6038 R14: 00007ffc7bd6c150 R15: 00007ffc7bd6c238
 </TASK>
INFO: task syz.2.1831:10958 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1831      state:D stack:24432 pid:10958 ppid:5800   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
 rwsem_down_write_slowpath+0xbd2/0xfa0 kernel/locking/rwsem.c:1178
 __down_write_common kernel/locking/rwsem.c:1306 [inline]
 __down_write kernel/locking/rwsem.c:1315 [inline]
 down_write+0x1a7/0x1f0 kernel/locking/rwsem.c:1574
 mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 exit_mmap+0x245/0xb50 mm/mmap.c:3310
 __mmput+0x118/0x3c0 kernel/fork.c:1355
 exit_mm+0x1da/0x2c0 kernel/exit.c:569
 do_exit+0x88e/0x23c0 kernel/exit.c:870
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
 get_signal+0x12fc/0x1400 kernel/signal.c:2902
 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb4b358f749
RSP: 002b:00007fb4b44e80e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fb4b37e5fa8 RCX: 00007fb4b358f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb4b37e5fa8
RBP: 00007fb4b37e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb4b37e6038 R14: 00007ffd85dabc30 R15: 00007ffd85dabd18
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
1 lock held by syslogd/5141:
 #0: ffff8880b8e3c218 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558
2 locks held by udevd/5159:
 #0: ffffffff8cdd2050 (dup_mmap_sem){++++}-{0:0}, at: dup_mmap kernel/fork.c:657 [inline]
 #0: ffffffff8cdd2050 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1692 [inline]
 #0: ffffffff8cdd2050 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x268/0x1ca0 kernel/fork.c:1741
 #1: ffff88807d1f5720 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline]
 #1: ffff88807d1f5720 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:658 [inline]
 #1: ffff88807d1f5720 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1692 [inline]
 #1: ffff88807d1f5720 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x283/0x1ca0 kernel/fork.c:1741
2 locks held by getty/5556:
 #0: ffff88814dc680a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
1 lock held by syz-executor/5781:
 #0: ffff88802e871e20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline]
 #0: ffff88802e871e20 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x168/0x400 mm/util.c:554
1 lock held by syz-executor/5791:
 #0: ffff88802e874da0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 #0: ffff88802e874da0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz-executor/5793:
 #0: ffff88802e875720 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 #0: ffff88802e875720 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz.0.1829/10951:
 #0: ffff88801786baa0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 #0: ffff88801786baa0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz.3.1830/10956:
 #0: ffff88801786f3a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 #0: ffff88801786f3a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz.2.1831/10958:
 #0: ffff8880439a9e20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 #0: ffff8880439a9e20 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
2 locks held by syz-executor/10966:
 #0: ffffffff8cdd2050 (dup_mmap_sem){++++}-{0:0}, at: dup_mmap kernel/fork.c:657 [inline]
 #0: ffffffff8cdd2050 (dup_mmap_sem){++++}-{0:0}, at: dup_mm kernel/fork.c:1692 [inline]
 #0: ffffffff8cdd2050 (dup_mmap_sem){++++}-{0:0}, at: copy_mm+0x268/0x1ca0 kernel/fork.c:1741
 #1: ffff88807d1f6a20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:124 [inline]
 #1: ffff88807d1f6a20 (&mm->mmap_lock){++++}-{3:3}, at: dup_mmap kernel/fork.c:658 [inline]
 #1: ffff88807d1f6a20 (&mm->mmap_lock){++++}-{3:3}, at: dup_mm kernel/fork.c:1692 [inline]
 #1: ffff88807d1f6a20 (&mm->mmap_lock){++++}-{3:3}, at: copy_mm+0x283/0x1ca0 kernel/fork.c:1741
1 lock held by syz-executor/10971:
 #0: ffff88807d1f4420 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 #0: ffff88807d1f4420 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz.7.1907/11267:
 #0: ffff8880178694a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 #0: ffff8880178694a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz.4.1910/11268:
 #0: ffff8880449b81a0 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 #0: ffff8880449b81a0 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310
1 lock held by syz.6.1909/11271:
 #0: ffff888017869e20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock include/linux/mmap_lock.h:108 [inline]
 #0: ffff888017869e20 (&mm->mmap_lock){++++}-{3:3}, at: exit_mmap+0x245/0xb50 mm/mmap.c:3310

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x39b/0x3d0 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+0xf41/0xf80 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
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5148 Comm: klogd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:deref_stack_reg+0x24/0x240 arch/x86/kernel/unwind_orc.c:402
Code: 00 00 00 0f 1f 00 55 41 57 41 56 41 55 41 54 53 48 83 ec 28 48 89 54 24 20 48 89 34 24 49 89 ff 48 bd 00 00 00 00 00 fc ff df <e8> 17 c0 4a 00 49 8d 5f 08 48 89 d8 48 c1 e8 03 48 89 44 24 10 80
RSP: 0018:ffffc90003287318 EFLAGS: 00000296
RAX: fffffffffffffff0 RBX: ffffffff8f4990c1 RCX: 0000000000000003
RDX: ffffc90003287488 RSI: ffffc90003287ed0 RDI: ffffc90003287448
RBP: dffffc0000000000 R08: ffff88807d5e1e00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000000 R12: ffffc90003287448
R13: dffffc0000000000 R14: ffffffff8f4990c0 R15: ffffc90003287448
FS:  00007f6ec67e9c80(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d517457168 CR3: 00000000307d5000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 unwind_next_frame+0x1789/0x2970 arch/x86/kernel/unwind_orc.c:648
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1007 [inline]
 __kmalloc_node_track_caller+0xb2/0x230 mm/slab_common.c:1027
 kmalloc_reserve+0x117/0x260 net/core/skbuff.c:581
 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:650
 alloc_skb include/linux/skbuff.h:1284 [inline]
 alloc_skb_with_frags+0xca/0x7c0 net/core/skbuff.c:6328
 sock_alloc_send_pskb+0x857/0x990 net/core/sock.c:2821
 unix_dgram_sendmsg+0x5a1/0x1720 net/unix/af_unix.c:2001
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x46a/0x620 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:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6ec6939407
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:00007ffcb63c8c60 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f6ec67e9c80 RCX: 00007f6ec6939407
RDX: 000000000000004d RSI: 00007ffcb63c8da0 RDI: 0000000000000003
RBP: 00007ffcb63c91d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffcb63c91e8
R13: 00007ffcb63c8da0 R14: 0000000000000032 R15: 00007ffcb63c8da0
 </TASK>