INFO: task syz.8.804:12232 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.804 state:D stack:24576 pid:12232 tgid:12230 ppid:11183 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x14fb/0x52c0 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7285 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 __super_lock fs/super.c:58 [inline] super_lock+0x289/0x3d0 fs/super.c:122 super_lock_excl fs/super.c:147 [inline] grab_super+0xb9/0x380 fs/super.c:533 sget_fc+0x2c2/0xa40 fs/super.c:804 sget_dev fs/super.c:1408 [inline] get_tree_bdev_flags+0x214/0x4f0 fs/super.c:1680 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3760 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3836 do_mount fs/namespace.c:4159 [inline] __do_sys_mount fs/namespace.c:4348 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4325 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: 0033:0x7f545860c629 RSP: 002b:00007f5456866028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f5458885fa0 RCX: 00007f545860c629 RDX: 0000200000000040 RSI: 0000200000000000 RDI: 0000200000000180 RBP: 00007f54586a2b39 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000080c80e R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5458886038 R14: 00007f5458885fa0 R15: 00007ffd71b932d8 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:11/1397: 2 locks held by udevd/5166: 2 locks held by getty/5561: #0: ffff88803708f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/8938: 1 lock held by syz.8.804/12232: #0: ffff88803c5b40d0 (&type->s_umount_key#63){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88803c5b40d0 (&type->s_umount_key#63){++++}-{4:4}, at: super_lock+0x289/0x3d0 fs/super.c:122 3 locks held by syz-executor/13903: #0: ffff88803b45c480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88806113ef90 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff88806113ef90 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline] #1: ffff88806113ef90 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline] #1: ffff88806113ef90 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_rmdir+0x1cd/0x520 fs/namei.c:5386 #2: ffff888079a91090 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #2: ffff888079a91090 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: vfs_rmdir+0x109/0x6f0 fs/namei.c:5323 1 lock held by syz.1.1132/14690: 3 locks held by syz.5.1134/14696: #0: ffff88802aba20d0 (&type->s_umount_key#79/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 #1: ffffffff8e3d90b8 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree_super fs/btrfs/super.c:1926 [inline] #1: ffffffff8e3d90b8 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree_subvol fs/btrfs/super.c:2087 [inline] #1: ffffffff8e3d90b8 (uuid_mutex){+.+.}-{4:4}, at: btrfs_get_tree+0x82b/0x1930 fs/btrfs/super.c:2121 #2: ffffffff8deab098 (lock#3){+.+.}-{4:4}, at: __lru_add_drain_all+0x6b/0x5e0 mm/swap.c:840 4 locks held by syz.6.1136/14704: 1 lock held by syz.0.1138/14711: #0: ffff88806aefa0d0 (&type->s_umount_key#90/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 1 lock held by dhcpcd-run-hook/14712: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(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:467 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: 5166 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:kasan_quarantine_reduce+0x0/0x160 mm/kasan/quarantine.c:240 Code: 50 72 5f 99 4c 3b 35 d7 86 35 17 73 aa eb c2 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <0f> 1f 40 d6 53 48 83 ec 20 48 c7 44 24 18 00 00 00 00 48 c7 44 24 RSP: 0018:ffffc90003e0fc38 EFLAGS: 00000206 RAX: 0000000000000001 RBX: ffff88805e257900 RCX: 0000000000000001 RDX: 0000000000000cc0 RSI: ffff88805e257900 RDI: ffff88801b29f140 RBP: 0000000000000cc0 R08: ffffffff8f6a25b7 R09: 1ffffffff1ed44b6 R10: dffffc0000000000 R11: fffffbfff1ed44b7 R12: ffff888038f10000 R13: ffff8880b8844340 R14: ffff88801b29f140 R15: 0000000000000001 FS: 00007f8d1cc1a880(0000) GS:ffff888126343000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffccd26f648 CR3: 0000000039646000 CR4: 00000000003526f0 Call Trace: __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4501 [inline] slab_alloc_node mm/slub.c:4830 [inline] kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4837 alloc_filename fs/namei.c:142 [inline] do_getname+0x2e/0x250 fs/namei.c:182 getname include/linux/fs.h:2512 [inline] getname_maybe_null include/linux/fs.h:2519 [inline] class_filename_maybe_null_constructor include/linux/fs.h:2543 [inline] vfs_fstatat+0x45/0x170 fs/stat.c:368 __do_sys_newfstatat fs/stat.c:538 [inline] __se_sys_newfstatat fs/stat.c:532 [inline] __x64_sys_newfstatat+0x151/0x200 fs/stat.c:532 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: 0033:0x7f8d1cd72b0a Code: 48 8b 15 f1 f2 0d 00 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 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 07 31 c0 c3 0f 1f 40 00 48 8b 15 b9 f2 0d 00 f7 RSP: 002b:00007fff0f941808 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007fff0f941ca0 RCX: 00007f8d1cd72b0a RDX: 00007fff0f941810 RSI: 00007fff0f941ca0 RDI: 00000000ffffff9c RBP: 00005563520de910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff0f9418a0 R13: 000055632d0cb100 R14: 00005563520ed280 R15: 00007fff0f9431c0