INFO: task syz.3.82:6191 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.82 state:D stack:28328 pid:6191 ppid:5770 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 rwsem_down_write_slowpath+0xc05/0xff0 kernel/locking/rwsem.c:1178 __down_write_common kernel/locking/rwsem.c:1306 [inline] __down_write kernel/locking/rwsem.c:1315 [inline] down_write_nested+0x1c3/0x200 kernel/locking/rwsem.c:1690 inode_lock_nested include/linux/fs.h:839 [inline] filename_create+0x20c/0x480 fs/namei.c:3890 do_mknodat+0x18b/0x500 fs/namei.c:4036 __do_sys_mknod fs/namei.c:4082 [inline] __se_sys_mknod fs/namei.c:4080 [inline] __x64_sys_mknod+0x8e/0xa0 fs/namei.c:4080 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f5cd9b9c819 RSP: 002b:00007f5cdaacd028 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 00007f5cd9e16180 RCX: 00007f5cd9b9c819 RDX: 0000000000000706 RSI: 0000000000000020 RDI: 0000200000000240 RBP: 00007f5cd9c32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5cd9e16218 R14: 00007f5cd9e16180 R15: 00007ffd2a0c4ab8 INFO: task syz.3.82:6192 blocked for more than 145 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.82 state:D stack:26408 pid:6192 ppid:5770 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 rwsem_down_write_slowpath+0xc05/0xff0 kernel/locking/rwsem.c:1178 __down_write_common kernel/locking/rwsem.c:1306 [inline] __down_write kernel/locking/rwsem.c:1315 [inline] down_write_nested+0x1c3/0x200 kernel/locking/rwsem.c:1690 inode_lock_nested include/linux/fs.h:839 [inline] filename_create+0x20c/0x480 fs/namei.c:3890 do_mkdirat+0xa9/0x450 fs/namei.c:4136 __do_sys_mkdirat fs/namei.c:4159 [inline] __se_sys_mkdirat fs/namei.c:4157 [inline] __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4157 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f5cd9b9b687 RSP: 002b:00007f5cdaaabe58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f5cdaaabee0 RCX: 00007f5cd9b9b687 RDX: 00000000000001ff RSI: 00002000000002c0 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000200000000240 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000002c0 R13: 00007f5cdaaabea0 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d1320a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 3 locks held by kworker/u4:4/59: #0: ffff888142eff138 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888142eff138 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc900015a7d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc900015a7d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #2: ffffffff8d137a78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #2: ffffffff8d137a78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004 4 locks held by kworker/u4:14/3551: #0: ffff88801ce4fd38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff88801ce4fd38 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc9000d287d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc9000d287d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #2: ffff8880586a20e0 (&type->s_umount_key#74){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607 #3: ffff88805b473008 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: jfs_commit_inode+0x1cb/0x520 fs/jfs/inode.c:108 2 locks held by getty/5527: #0: ffff8880317c10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217 2 locks held by kworker/1:5/5828: #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc90004a3fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc90004a3fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 4 locks held by syz.3.82/6190: 2 locks held by syz.3.82/6191: #0: ffff8880586a2418 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412 #1: ffff88805b4733d0 (&type->i_mutex_dir_key#12/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline] #1: ffff88805b4733d0 (&type->i_mutex_dir_key#12/1){+.+.}-{3:3}, at: filename_create+0x20c/0x480 fs/namei.c:3890 2 locks held by syz.3.82/6192: #0: ffff8880586a2418 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412 #1: ffff88805b4733d0 (&type->i_mutex_dir_key#12/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline] #1: ffff88805b4733d0 (&type->i_mutex_dir_key#12/1){+.+.}-{3:3}, at: filename_create+0x20c/0x480 fs/namei.c:3890 6 locks held by syz-executor/7374: #0: ffff88807aa9c418 (sb_writers#10){.+.+}-{0:0}, at: vfs_write+0x21b/0x990 fs/read_write.c:580 #1: ffff8880253fd888 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e7/0x520 fs/kernfs/file.c:343 #2: ffffffff8d15bb08 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:369 [inline] #2: ffffffff8d15bb08 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0xf2/0x230 kernel/cgroup/cgroup.c:1677 #3: ffffffff8cfcd270 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2414 [inline] #3: ffffffff8cfcd270 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x18a/0x610 kernel/cgroup/cgroup.c:2919 #4: ffffffff8d15bcf0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2416 [inline] #4: ffffffff8d15bcf0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x1a0/0x610 kernel/cgroup/cgroup.c:2919 #5: ffffffff8d137a78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #5: ffffffff8d137a78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf3d/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 7374 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:__lock_acquire+0x52e/0x7d40 kernel/locking/lockdep.c:5085 Code: 09 c7 45 09 ef 41 09 df 48 8b 44 24 48 42 0f b6 04 00 84 c0 0f 85 4e 64 00 00 44 8b 75 28 48 8b 84 24 90 00 00 00 44 89 78 20 <48> 8d 58 24 48 89 d8 48 c1 e8 03 42 0f b6 04 00 84 c0 4c 8b 6c 24 RSP: 0018:ffffc900031e6f80 EFLAGS: 00000046 RAX: ffff888023a946e0 RBX: 0000000000040000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888023a946e8 RBP: ffffc900031e71c8 R08: dffffc0000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1d16056 R12: ffff888023a946c4 R13: 00000000000000b1 R14: 0000000000000000 R15: 00000000000400b1 FS: 000055557bdcf500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fea55d46440 CR3: 0000000068941000 CR4: 00000000003506e0 Call Trace: lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 __fs_reclaim_acquire mm/page_alloc.c:3599 [inline] fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:3613 might_alloc include/linux/sched/mm.h:303 [inline] prepare_alloc_pages+0x15a/0x5f0 mm/page_alloc.c:4270 __alloc_pages+0x134/0x460 mm/page_alloc.c:4489 __alloc_pages_bulk+0x49c/0x940 mm/page_alloc.c:4448 vm_area_alloc_pages mm/vmalloc.c:3055 [inline] __vmalloc_area_node mm/vmalloc.c:3158 [inline] __vmalloc_node_range+0x721/0x1330 mm/vmalloc.c:3339 __vmalloc_node mm/vmalloc.c:3404 [inline] vmalloc+0x79/0x90 mm/vmalloc.c:3437 ebt_register_table+0x20c/0x10b0 net/bridge/netfilter/ebtables.c:1206 find_inlist_lock_noload+0x178/0x260 net/bridge/netfilter/ebtables.c:343 find_inlist_lock net/bridge/netfilter/ebtables.c:370 [inline] find_table_lock net/bridge/netfilter/ebtables.c:379 [inline] do_ebt_get_ctl+0x2d6/0x1d80 net/bridge/netfilter/ebtables.c:2468 nf_getsockopt+0x262/0x280 net/netfilter/nf_sockopt.c:116 ip_getsockopt+0x19f/0x230 net/ipv4/ip_sockglue.c:1790 do_sock_getsockopt+0x379/0x450 net/socket.c:2383 __sys_getsockopt net/socket.c:2412 [inline] __do_sys_getsockopt net/socket.c:2422 [inline] __se_sys_getsockopt net/socket.c:2419 [inline] __x64_sys_getsockopt+0x1d6/0x280 net/socket.c:2419 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fa39f39dfea Code: 48 83 ec 10 89 d2 48 63 ff 45 31 c9 6a 2a 45 31 c0 31 c9 e8 d8 99 fb ff 48 83 c4 18 c3 0f 1f 00 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 e8 ff ff ff f7 RSP: 002b:00007ffea3df9778 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 00007fa39f5e6a60 RCX: 00007fa39f39dfea RDX: 0000000000000082 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffea3df9810 R09: 0000000000000000 R10: 00007fa39f5e6a68 R11: 0000000000000246 R12: 00007fa39f5e6a68 R13: 00007fa39f5e63e0 R14: 0000000000000003 R15: 00007ffea3df9810