INFO: task syz.5.138:6928 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.138 state:D stack:28904 pid:6928 tgid:6888 ppid:6142 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7118 rwsem_down_write_slowpath+0x872/0xfe0 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1591 inode_lock include/linux/fs.h:980 [inline] vfs_removexattr+0x6c/0x1b0 fs/xattr.c:574 removexattr fs/xattr.c:1023 [inline] filename_removexattr fs/xattr.c:1052 [inline] path_removexattrat+0x35d/0x690 fs/xattr.c:1088 __do_sys_lremovexattr fs/xattr.c:1106 [inline] __se_sys_lremovexattr fs/xattr.c:1103 [inline] __x64_sys_lremovexattr+0x65/0x80 fs/xattr.c:1103 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: 0033:0x7f2cb758eba9 RSP: 002b:00007f2cb844f038 EFLAGS: 00000246 ORIG_RAX: 00000000000000c6 RAX: ffffffffffffffda RBX: 00007f2cb77d6090 RCX: 00007f2cb758eba9 RDX: 0000000000000000 RSI: 0000200000000180 RDI: 00002000000000c0 RBP: 00007f2cb7611e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2cb77d6128 R14: 00007f2cb77d6090 R15: 00007ffea4a55518 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e33c820 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e33c820 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e33c820 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5623: #0: ffff88814d7590a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 4 locks held by syz.5.138/6889: #0: ffff8880281f4420 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:574 #1: ffff8880562673b0 (&inode->i_sb->s_type->i_mutex_dir_key){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #1: ffff8880562673b0 (&inode->i_sb->s_type->i_mutex_dir_key){+.+.}-{4:4}, at: vfs_setxattr+0x144/0x2f0 fs/xattr.c:320 #2: ffff8880281f4610 (sb_internal#2){.+.+}-{0:0}, at: xfs_trans_alloc+0xd7/0x980 fs/xfs/xfs_trans.c:256 #3: ffff888056267198 (&xfs_dir_ilock_class){++++}-{4:4}, at: xfs_trans_alloc_inode+0x161/0x4a0 fs/xfs/xfs_trans.c:1081 2 locks held by syz.5.138/6928: #0: ffff8880281f4420 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:574 #1: ffff8880562673b0 (&inode->i_sb->s_type->i_mutex_dir_key){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #1: ffff8880562673b0 (&inode->i_sb->s_type->i_mutex_dir_key){+.+.}-{4:4}, at: vfs_removexattr+0x6c/0x1b0 fs/xattr.c:574 1 lock held by udevd/7502: 2 locks held by syz.0.537/8814: #0: ffff8880634c1348 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #0: ffff8880634c1348 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: __sock_release net/socket.c:648 [inline] #0: ffff8880634c1348 (&sb->s_type->i_mutex_key#11){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1442 #1: ffffffff8f740a48 (rtnl_mutex){+.+.}-{4:4}, at: raw_release+0x1bb/0x980 net/can/raw.c:418 3 locks held by syz.1.541/8828: #0: ffffffff8f733bb0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0 net/core/net_namespace.c:566 #1: ffffffff8f740a48 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xdc/0x890 net/core/dev.c:12768 #2: ffffffff8e3422b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #2: ffffffff8e3422b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957 1 lock held by syz.2.545/8851: #0: ffffffff8f740a48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f740a48 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x323/0x1b50 net/ipv4/devinet.c:1120 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: 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 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8814 Comm: syz.0.537 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:lock_release+0x2cd/0x3e0 kernel/locking/lockdep.c:5893 Code: 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 9b 10 26 11 48 3b 44 24 28 0f 85 8b 00 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e 41 5f <5d> e9 bd 7a e8 09 cc 90 0f 0b 90 e9 5d fd ff ff 90 0f 0b 90 48 c7 RSP: 0018:ffffc9001e6f6d68 EFLAGS: 00000282 RAX: d2966c29c79dcd00 RBX: ffffffff9054dd01 RCX: d2966c29c79dcd00 RDX: 0000000000000000 RSI: ffffffff8ddae1af RDI: ffffffff8c036f00 RBP: ffff88802589c7b0 R08: ffffc9001e6f7c80 R09: 0000000000000000 R10: ffffc9001e6f6e98 R11: fffff52003cdedd5 R12: ffffc9001e6f7c90 R13: ffffc9001e6f0000 R14: ffffc9001e6f6e48 R15: ffffffff8173bd25 FS: 0000000000000000(0000) GS:ffff8881259e8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000560a0a376b50 CR3: 0000000077a8c000 CR4: 00000000003526f0 Call Trace: rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1169 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] free_unref_folios+0xdb3/0x14f0 mm/page_alloc.c:2963 folios_put_refs+0x584/0x670 mm/swap.c:1002 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1120 shmem_truncate_range mm/shmem.c:1232 [inline] shmem_evict_inode+0x272/0xa70 mm/shmem.c:1360 evict+0x504/0x9c0 fs/inode.c:810 __dentry_kill+0x209/0x660 fs/dcache.c:669 dput+0x19f/0x2b0 fs/dcache.c:911 __fput+0x68e/0xa70 fs/file_table.c:476 task_work_run+0x1d4/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:966 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 get_signal+0x1286/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x75/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe51dd8eba9 Code: Unable to access opcode bytes at 0x7fe51dd8eb7f. RSP: 002b:00007ffca13495e8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fe51dfd7da0 RCX: 00007fe51dd8eba9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fe51dfd7da0 R08: 0000000000023bc4 R09: 0000001ea13498df R10: 00007fe51dfd7cb0 R11: 0000000000000246 R12: 000000000004fc0a R13: 00007fe51dfd6180 R14: ffffffffffffffff R15: 00007ffca1349700