INFO: task syz.5.1591:12398 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.1591 state:D stack:25408 pid:12398 tgid:12388 ppid:6009 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 __wait_on_freeing_inode+0x166/0x3b0 fs/inode.c:2560 find_inode_fast+0x30c/0x550 fs/inode.c:1109 iget_locked+0xd0/0x6a0 fs/inode.c:1467 __ext4_iget+0x242/0x4290 fs/ext4/inode.c:5146 ext4_xattr_inode_cache_find fs/ext4/xattr.c:1550 [inline] ext4_xattr_inode_lookup_create+0x447/0x1cf0 fs/ext4/xattr.c:1589 ext4_xattr_block_set+0x229/0x2ad0 fs/ext4/xattr.c:1918 ext4_xattr_set_handle+0xe34/0x14c0 fs/ext4/xattr.c:2457 ext4_xattr_set+0x255/0x340 fs/ext4/xattr.c:2559 __vfs_setxattr+0x43c/0x480 fs/xattr.c:200 __vfs_setxattr_noperm+0x12d/0x660 fs/xattr.c:234 vfs_setxattr+0x163/0x360 fs/xattr.c:321 do_setxattr fs/xattr.c:636 [inline] filename_setxattr+0x296/0x630 fs/xattr.c:664 path_setxattrat+0x3eb/0x440 fs/xattr.c:708 __do_sys_setxattr fs/xattr.c:742 [inline] __se_sys_setxattr fs/xattr.c:738 [inline] __x64_sys_setxattr+0xbc/0xe0 fs/xattr.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7eb899c799 RSP: 002b:00007f7eb98aa028 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc RAX: ffffffffffffffda RBX: 00007f7eb8c16090 RCX: 00007f7eb899c799 RDX: 0000200000001400 RSI: 00002000000001c0 RDI: 00002000000000c0 RBP: 00007f7eb8a32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000835 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7eb8c16128 R14: 00007f7eb8c16090 R15: 00007fff664339c8 INFO: task syz.5.1591:12401 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.1591 state:D stack:24968 pid:12401 tgid:12388 ppid:6009 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 mb_cache_entry_wait_unused+0x17d/0x280 fs/mbcache.c:148 ext4_evict_ea_inode+0x14d/0x2f0 fs/ext4/xattr.c:481 ext4_evict_inode+0x165/0xeb0 fs/ext4/inode.c:185 evict+0x61e/0xb10 fs/inode.c:846 ext4_xattr_set_entry+0x12c6/0x1e20 fs/ext4/xattr.c:1849 ext4_xattr_block_set+0x621/0x2ad0 fs/ext4/xattr.c:1961 ext4_xattr_set_handle+0xe34/0x14c0 fs/ext4/xattr.c:2457 ext4_xattr_set+0x255/0x340 fs/ext4/xattr.c:2559 __vfs_setxattr+0x43c/0x480 fs/xattr.c:200 __vfs_setxattr_noperm+0x12d/0x660 fs/xattr.c:234 vfs_setxattr+0x163/0x360 fs/xattr.c:321 do_setxattr fs/xattr.c:636 [inline] filename_setxattr+0x296/0x630 fs/xattr.c:664 path_setxattrat+0x3eb/0x440 fs/xattr.c:708 __do_sys_setxattr fs/xattr.c:742 [inline] __se_sys_setxattr fs/xattr.c:738 [inline] __x64_sys_setxattr+0xbc/0xe0 fs/xattr.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7eb899c799 RSP: 002b:00007f7eb9889028 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc RAX: ffffffffffffffda RBX: 00007f7eb8c16180 RCX: 00007f7eb899c799 RDX: 0000200000000200 RSI: 00002000000001c0 RDI: 00002000000000c0 RBP: 00007f7eb8a32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000835 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7eb8c16218 R14: 00007f7eb8c16180 R15: 00007fff664339c8 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8e7648f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e7648f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 2 locks held by kworker/u8:1/13: #0: ffff8880202a2948 ((wq_completion)quota_events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff8880202a2948 ((wq_completion)quota_events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 2 locks held by ksoftirqd/1/23: 3 locks held by kworker/1:0/24: 1 lock held by khungtaskd/31: #0: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75e5e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5573: #0: ffff8880363fb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000331e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 6 locks held by kworker/u8:0/5964: 1 lock held by syz-executor/6010: #0: ffff888032b060e0 (&type->s_umount_key#32){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888032b060e0 (&type->s_umount_key#32){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888032b060e0 (&type->s_umount_key#32){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 1 lock held by syz-executor/6012: 1 lock held by udevd/6058: 1 lock held by udevd/10302: 3 locks held by syz.5.1591/12398: #0: ffff888036436420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88805861b3d8 (&sb->s_type->i_mutex_key#12){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff88805861b3d8 (&sb->s_type->i_mutex_key#12){++++}-{4:4}, at: vfs_setxattr+0x13e/0x360 fs/xattr.c:320 #2: ffff88805861b0c0 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] #2: ffff88805861b0c0 (&ei->xattr_sem){++++}-{4:4}, at: ext4_xattr_set_handle+0x19c/0x14c0 fs/ext4/xattr.c:2372 3 locks held by syz.5.1591/12401: #0: ffff888036436420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888059eb50a0 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff888059eb50a0 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: vfs_setxattr+0x13e/0x360 fs/xattr.c:320 #2: ffff888059eb4d88 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] #2: ffff888059eb4d88 (&ei->xattr_sem){++++}-{4:4}, at: ext4_xattr_set_handle+0x19c/0x14c0 fs/ext4/xattr.c:2372 1 lock held by syz.3.3137/18297: #0: ffff8880557580e0 (&type->s_umount_key#28/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:345 1 lock held by syz.2.3136/18302: 1 lock held by syz.6.3135/18304: 2 locks held by syz.4.3138/18307: #0: ffff8880260ac448 (&lo->lo_mutex){+.+.}-{4:4}, at: loop_global_lock_killable drivers/block/loop.c:118 [inline] #0: ffff8880260ac448 (&lo->lo_mutex){+.+.}-{4:4}, at: loop_configure+0x36f/0xdf0 drivers/block/loop.c:1016 #1: ffff88801bad5988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_activate fs/kernfs/dir.c:1430 [inline] #1: ffff88801bad5988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x2ae/0x5c0 fs/kernfs/dir.c:839 ============================================= 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 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 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: 18297 Comm: syz.3.3137 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401 Code: e8 1e a1 84 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 9f e9 ee fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 25 33 cf fb cc 44 89 f9 80 e1 07 RSP: 0018:ffffc90004887290 EFLAGS: 00000002 RAX: 1ffffffff34bab00 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffffff9a5d5c50 R08: ffff888141ac0237 R09: 1ffff11028358046 R10: dffffc0000000000 R11: ffffffff85410d60 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff9a5d59c0 R15: 0000000000000000 FS: 00007f3aa466a6c0(0000) GS:ffff888125459000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd1fdf5e000 CR3: 0000000057ab7000 CR4: 0000000000350ef0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:128 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline] wait_for_lsr+0xd1/0x2f0 drivers/tty/serial/8250/8250_port.c:1970 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3207 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3272 [inline] serial8250_console_write+0x1348/0x1ba0 drivers/tty/serial/8250/8250_port.c:3357 console_emit_next_record kernel/printk/printk.c:3183 [inline] console_flush_one_record kernel/printk/printk.c:3269 [inline] console_flush_all+0x718/0xb20 kernel/printk/printk.c:3343 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline] console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479 _printk+0xdd/0x130 kernel/printk/printk.c:2504 __ext4_msg+0x2b9/0x2d0 fs/ext4/super.c:995 ext4_fill_super+0x292a/0x6320 fs/ext4/super.c:5806 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3763 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3839 do_mount fs/namespace.c:4172 [inline] __do_sys_mount fs/namespace.c:4361 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4338 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3aa379da0a Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3aa4669e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f3aa4669ee0 RCX: 00007f3aa379da0a RDX: 0000200000000880 RSI: 00002000000008c0 RDI: 00007f3aa4669ea0 RBP: 0000200000000880 R08: 00007f3aa4669ee0 R09: 0000000000010000 R10: 0000000000010000 R11: 0000000000000246 R12: 00002000000008c0 R13: 00007f3aa4669ea0 R14: 000000000000084d R15: 0000200000000000