syzbot

INFO: task syz.4.9:5994 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc1-syzkaller-00157-g02adc1490e6d #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.9         state:D stack:25160 pid:5994  tgid:5990  ppid:5822   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 percpu_rwsem_wait+0x2e3/0x330 kernel/locking/percpu-rwsem.c:164
 __percpu_down_read+0xf0/0x130 kernel/locking/percpu-rwsem.c:180
 percpu_down_read_internal include/linux/percpu-rwsem.h:67 [inline]
 percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
 __sb_start_write include/linux/fs.h:1793 [inline]
 sb_start_write+0x18e/0x1c0 include/linux/fs.h:1929
 mnt_want_write+0x41/0x90 fs/namespace.c:557
 do_open fs/namei.c:3880 [inline]
 path_openat+0x2d4b/0x3830 fs/namei.c:4046
 do_filp_open+0x1fa/0x410 fs/namei.c:4073
 do_sys_openat2+0x121/0x1c0 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_open fs/open.c:1460 [inline]
 __se_sys_open fs/open.c:1456 [inline]
 __x64_sys_open+0x11e/0x150 fs/open.c:1456
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3a2778e929
RSP: 002b:00007f3a28559038 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f3a279b5fa0 RCX: 00007f3a2778e929
RDX: 00000000000000e1 RSI: 000000000014927e RDI: 00002000000001c0
RBP: 00007f3a27810b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f3a279b5fa0 R15: 00007ffcfb7a9af8
 </TASK>

Showing all locks held in the system:
2 locks held by kworker/u8:1/13:
1 lock held by khungtaskd/31:
 #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13eda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
1 lock held by udevd/5193:
 #0: ffff8880b873b798 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:606
2 locks held by getty/5583:
 #0: ffff8880312a90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by udevd/5832:
2 locks held by kworker/u8:8/5931:
 #0: ffff8880b873b798 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:606
 #1: ffffc90004a67bc0 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90004a67bc0 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
1 lock held by syz.4.9/5994:
 #0: ffff888056a02428 (sb_writers#15){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557
1 lock held by syz.8.281/8247:
 #0: ffff88804a9300e0 (&type->s_umount_key#51/1){+.+.}-{4:4}, at: alloc_super+0x204/0x970 fs/super.c:345
1 lock held by syz.3.283/8248:
2 locks held by dhcpcd/8252:
 #0: ffff88807de66e08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
 #0: ffff88807de66e08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release net/socket.c:646 [inline]
 #0: ffff88807de66e08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1391
 #1: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
 #1: ffffffff8e1448b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:998
2 locks held by dhcpcd-run-hook/8272:
 #0: ffff8880b863b798 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:606
 #1: ffff8880b8623f08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987
1 lock held by udevadm/8283:
3 locks held by dhcpcd-run-hook/8295:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc1-syzkaller-00157-g02adc1490e6d #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:470
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6187 Comm: udevd Not tainted 6.16.0-rc1-syzkaller-00157-g02adc1490e6d #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:mas_data_end lib/maple_tree.c:-1 [inline]
RIP: 0010:mas_rev_awalk lib/maple_tree.c:4848 [inline]
RIP: 0010:mas_empty_area_rev+0xf16/0x1ce0 lib/maple_tree.c:5153
Code: 89 f8 48 c1 e8 03 49 bd 00 00 00 00 00 fc ff df 42 0f b6 04 28 84 c0 0f 85 76 05 00 00 41 0f b6 2f 4c 8b 3c 24 e9 24 01 00 00 <4c> 89 6c 24 18 e8 f0 e0 69 f6 4d 8d 6f 08 eb 08 e8 e5 e0 69 f6 45
RSP: 0018:ffffc9000b1b7830 EFLAGS: 00000246
RAX: 0000000000000003 RBX: 0000000000000001 RCX: 0000000000000005
RDX: ffffffff8b566cef RSI: ffffffff8f86b6e0 RDI: 0000000000000001
RBP: ffffc9000b1b79c0 R08: ffff88802bf43c00 R09: 0000000000000003
R10: 0000000000000003 R11: 0000000000000000 R12: ffffc9000b1b79b8
R13: 1ffff92001636f39 R14: ffffc9000b1b79dd R15: ffff888021774400
FS:  00007ff7fcf52880(0000) GS:ffff888125c84000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff7fc7c7000 CR3: 0000000031a68000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 vma_iter_area_highest mm/vma.h:407 [inline]
 unmapped_area_topdown+0x211/0x590 mm/vma.c:2882
 vm_unmapped_area+0x69/0x230 mm/mmap.c:671
 arch_get_unmapped_area_topdown+0x97f/0xbc0 arch/x86/kernel/sys_x86_64.c:227
 mm_get_unmapped_area_vmflags mm/mmap.c:809 [inline]
 __get_unmapped_area+0x2a8/0x450 mm/mmap.c:854
 do_mmap+0x4ab/0x10d0 mm/mmap.c:409
 vm_mmap_pgoff+0x31b/0x4c0 mm/util.c:579
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff7fc91d822
Code: 00 00 00 0f 1f 44 00 00 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 3b 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 76 5b 5d c3 0f 1f 00 48 8b 05 a1 35 0d 00 64
RSP: 002b:00007ffd378ee288 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff7fc91d822
RDX: 0000000000000003 RSI: 0000000000000200 RDI: 0000000000000000
RBP: 0000000000000022 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000000018
R13: 0000000000200000 R14: 000055cd7aa81c80 R15: 0000000000001200
 </TASK>