syzbot

INFO: task udevd:11515 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:21864 pid:11515 tgid:11515 ppid:1      task_flags:0x400140 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 io_schedule+0x80/0xd0 kernel/sched/core.c:7871
 folio_wait_bit_common+0x6b0/0xb80 mm/filemap.c:1330
 folio_put_wait_locked mm/filemap.c:1494 [inline]
 do_read_cache_folio+0x1aa/0x590 mm/filemap.c:4006
 read_mapping_folio include/linux/pagemap.h:999 [inline]
 read_part_sector+0xb6/0x2b0 block/partitions/core.c:722
 adfspart_check_POWERTEC+0x8c/0xf30 block/partitions/acorn.c:454
 check_partition block/partitions/core.c:141 [inline]
 blk_add_partitions block/partitions/core.c:589 [inline]
 bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693
 blkdev_get_whole+0x380/0x510 block/bdev.c:748
 bdev_open+0x31e/0xd30 block/bdev.c:957
 blkdev_open+0x457/0x600 block/fops.c:701
 do_dentry_open+0x953/0x13f0 fs/open.c:965
 vfs_open+0x3b/0x340 fs/open.c:1097
 do_open fs/namei.c:3975 [inline]
 path_openat+0x2ee5/0x3830 fs/namei.c:4134
 do_filp_open+0x1fa/0x410 fs/namei.c:4161
 do_sys_openat2+0x121/0x1c0 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1463
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efcbd5d2407
RSP: 002b:00007ffc92522e30 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007efcbd546880 RCX: 00007efcbd5d2407
RDX: 00000000000a0800 RSI: 0000564b14d802e0 RDI: ffffffffffffff9c
RBP: 0000564b14d71910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000564b14d83b20
R13: 0000564b14d7f190 R14: 0000000000000000 R15: 0000564b14d83b20
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8df3d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df3d6a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8df3d6a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5582:
 #0: ffff88814db7c0a0 (&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/11515:
 #0: ffff8880249e7358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
2 locks held by syz.6.3437/21738:
 #0: ffffffff8f2be8f0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x337/0x4e0 net/core/net_namespace.c:576
 #1: ffffffff8f2cb788 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline]
 #1: ffffffff8f2cb788 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x990 net/core/net_namespace.c:248
2 locks held by syz.2.3438/21726:
 #0: ffff888022a887c8 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline]
 #0: ffff888022a887c8 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline]
 #0: ffff888022a887c8 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455
 #1: ffffffff8df43138 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #1: ffffffff8df43138 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957
2 locks held by syz.2.3438/21727:
 #0: ffffffff8f331610 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
 #1: ffffffff8f2cb788 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_pre_doit+0x5f/0x930 net/wireless/nl80211.c:17926
4 locks held by syz.7.3439/21739:
2 locks held by syz.8.3430/21744:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
 watchdog+0xf60/0xfa0 kernel/hung_task.c:495
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 21744 Comm: syz.8.3430 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:cpuacct_charge+0x1df/0x320 kernel/sched/cpuacct.c:344
Code: a7 fc 8b 00 4d 8b 6d 00 41 83 fe 08 73 4c 80 3c 2b 00 74 08 4c 89 ff e8 8f fc 8b 00 4d 03 2f 4c 89 e8 48 c1 e8 03 80 3c 28 00 <74> 08 4c 89 ef e8 77 fc 8b 00 48 8b 04 24 49 01 45 00 49 81 c4 08
RSP: 0018:ffffc900050ee510 EFLAGS: 00000046
RAX: 1ffffd1ffffa5cf9 RBX: 1ffffffff1b25bbb RCX: 00809873afb53700
RDX: 0000000000000000 RSI: ffffffff8d8f462c RDI: ffffffff8bbf0760
RBP: dffffc0000000000 R08: ffffffff8f7ce377 R09: 1ffffffff1ef9c6e
R10: dffffc0000000000 R11: fffffbfff1ef9c6f R12: ffff8880562bf000
R13: ffffe8ffffd2e7c8 R14: 0000000000000001 R15: ffffffff8d92ddd8
FS:  00007f4e01ff66c0(0000) GS:ffff88812623b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555792dc5c8 CR3: 0000000020a84000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 cgroup_account_cputime include/linux/cgroup.h:740 [inline]
 update_se+0x2ba/0x5f0 kernel/sched/fair.c:1179
 update_curr+0x75/0x730 kernel/sched/fair.c:1223
 put_prev_entity+0x41/0x230 kernel/sched/fair.c:5545
 put_prev_task_fair+0x4b/0x80 kernel/sched/fair.c:8984
 put_prev_set_next_task kernel/sched/sched.h:2503 [inline]
 pick_next_task kernel/sched/core.c:6264 [inline]
 __schedule+0x4312/0x4cc0 kernel/sched/core.c:6870
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:rcu_read_unlock include/linux/rcupdate.h:895 [inline]
RIP: 0010:class_rcu_destructor include/linux/rcupdate.h:1195 [inline]
RIP: 0010:unwind_next_frame+0x195e/0x2390 arch/x86/kernel/unwind_orc.c:680
Code: c6 03 01 4c 8b 7c 24 48 4c 8b 64 24 20 41 0f b6 04 2c 84 c0 0f 85 2d 03 00 00 41 c7 06 00 00 00 00 31 db e8 d4 b3 d2 09 85 c0 <74> 3a e8 9b aa 32 00 84 c0 75 31 e8 c2 b3 d2 09 85 c0 74 28 80 3d
RSP: 0018:ffffc900050eea18 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff9098b301 RCX: ffff888055ce1e40
RDX: ffffc900050eeb01 RSI: dffffc0000000000 RDI: ffffc900050eeaf0
RBP: dffffc0000000000 R08: ffffc900050ef530 R09: ffffc900050eeb38
R10: dffffc0000000000 R11: fffff52000a1dd69 R12: ffffc900050ef540
R13: ffffc900050e8000 R14: ffffc900050eeae8 R15: ffffffff81738c45
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:417
 kasan_kmalloc include/linux/kasan.h:262 [inline]
 __kmalloc_cache_noprof+0x3d5/0x6f0 mm/slub.c:5767
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 nh_notifier_res_bucket_info_init net/ipv4/nexthop.c:321 [inline]
 __call_nexthop_res_bucket_notifiers+0x455/0xc70 net/ipv4/nexthop.c:355
 replace_nexthop_single_notify_res net/ipv4/nexthop.c:2346 [inline]
 replace_nexthop_single_notify+0x356/0x640 net/ipv4/nexthop.c:2386
 replace_nexthop_single net/ipv4/nexthop.c:2443 [inline]
 replace_nexthop net/ipv4/nexthop.c:2567 [inline]
 insert_nexthop net/ipv4/nexthop.c:2607 [inline]
 nexthop_add net/ipv4/nexthop.c:2973 [inline]
 rtm_new_nexthop+0x6b54/0x8140 net/ipv4/nexthop.c:3277
 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6951
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 ____sys_sendmsg+0x505/0x830 net/socket.c:2630
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
 __sys_sendmsg net/socket.c:2716 [inline]
 __do_sys_sendmsg net/socket.c:2721 [inline]
 __se_sys_sendmsg net/socket.c:2719 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4e03d8f6c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4e01ff6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f4e03fe6180 RCX: 00007f4e03d8f6c9
RDX: 0000000000000000 RSI: 0000200000000100 RDI: 000000000000000a
RBP: 00007f4e03e11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4e03fe6218 R14: 00007f4e03fe6180 R15: 00007ffed5534598
 </TASK>