INFO: task syz.4.338:8243 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.338 state:D stack:24712 pid:8243 tgid:8242 ppid:5811 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 io_schedule+0x81/0xe0 kernel/sched/core.c:7871 folio_wait_bit_common+0x6b5/0xb90 mm/filemap.c:1330 folio_lock include/linux/pagemap.h:1141 [inline] release_metapage+0x103/0xab0 fs/jfs/jfs_metapage.c:870 discard_metapage fs/jfs/jfs_metapage.h:88 [inline] __get_metapage+0x9a0/0xde0 fs/jfs/jfs_metapage.c:753 dtSplitPage+0x7f8/0x3b20 fs/jfs/jfs_dtree.c:1471 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline] dtInsert+0x109b/0x5f40 fs/jfs/jfs_dtree.c:871 jfs_mkdir+0x6ec/0xa70 fs/jfs/namei.c:270 vfs_mkdir+0x306/0x510 fs/namei.c:4453 do_mkdirat+0x247/0x590 fs/namei.c:4486 __do_sys_mkdirat fs/namei.c:4503 [inline] __se_sys_mkdirat fs/namei.c:4501 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4501 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: 0033:0x7fa63a6ed617 RSP: 002b:00007fa63894de68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fa63894def0 RCX: 00007fa63a6ed617 RDX: 00000000000001ff RSI: 0000200000000240 RDI: 00000000ffffff9c RBP: 0000200000000200 R08: 00002000000000c0 R09: 0000000000000000 R10: 0000200000000200 R11: 0000000000000246 R12: 0000200000000240 R13: 00007fa63894deb0 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 4 locks held by kworker/u8:0/12: 1 lock held by khungtaskd/39: #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d7aa4c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:6/189: 3 locks held by kworker/u8:7/1170: #0: ffff88814ce1f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88814ce1f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90004eafba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90004eafba0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194 3 locks held by kworker/u8:10/1394: #0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813fe29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc900054dfba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc900054dfba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 4 locks held by kworker/u8:12/1449: #0: ffff8881432aa938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff8881432aa938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc900055efba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc900055efba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff88804a6d60d0 (&type->s_umount_key#57){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562 #3: ffff88805c5b01e8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108 2 locks held by dhcpcd/5465: #0: ffff88804c754918 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2406 #1: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6822 2 locks held by getty/5562: #0: ffff88823bf6c8a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222 4 locks held by syz.4.338/8243: #0: ffff88804a6d6480 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:508 #1: ffff88805c5b05b8 (&type->i_mutex_dir_key#10/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1025 [inline] #1: ffff88805c5b05b8 (&type->i_mutex_dir_key#10/1){+.+.}-{4:4}, at: filename_create+0x1f8/0x3c0 fs/namei.c:4226 #2: ffff88805c5b01e8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_mkdir+0x1fb/0xa70 fs/jfs/namei.c:233 #3: ffff88805c6e1f28 (&jfs_ip->commit_mutex/1){+.+.}-{4:4}, at: jfs_mkdir+0x216/0xa70 fs/jfs/namei.c:234 1 lock held by syz-executor/9130: #0: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3436 2 locks held by syz-executor/9291: #0: ffffffff8e202ba0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e202ba0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e202ba0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 1 lock held by syz-executor/9894: #0: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8ea778f8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978 1 lock held by syz.7.496/9933: 2 locks held by syz.9.497/9944: 2 locks held by syz.5.498/9946: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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: 9944 Comm: syz.9.497 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:blk_cgroup_congested+0xf9/0x210 block/blk-cgroup.c:2245 Code: fc ff df 4d 8d be a4 01 00 00 4c 89 ff be 04 00 00 00 e8 7a cc bd fd 4c 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 75 40 41 8b 2f <31> ff 89 ee e8 9e 1c 5c fd 85 ed 40 0f 95 c5 75 4c 49 81 c6 08 01 RSP: 0018:ffffc9000c9ff778 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffffff8462d45d RCX: ffffffff8462d526 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff98f4ed04 RBP: 0000000000000000 R08: ffffffff98f4ed07 R09: 1ffffffff31e9da0 R10: dffffc0000000000 R11: fffffbfff31e9da1 R12: dffffc0000000000 R13: 00000000000009e4 R14: ffffffff98f4eb60 R15: ffffffff98f4ed04 FS: 00007fa983f3e6c0(0000) GS:ffff888126bc9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f927d6fe000 CR3: 000000005965a000 CR4: 00000000003526f0 Call Trace: __folio_throttle_swaprate+0x67/0x190 mm/swapfile.c:4065 folio_throttle_swaprate include/linux/swap.h:617 [inline] shmem_add_to_page_cache+0x6f1/0xbc0 mm/shmem.c:882 shmem_alloc_and_add_folio mm/shmem.c:1936 [inline] shmem_get_folio_gfp+0x7d2/0x1a70 mm/shmem.c:2533 shmem_get_folio mm/shmem.c:2639 [inline] shmem_write_begin+0xef/0x2a0 mm/shmem.c:3289 generic_perform_write+0x29d/0x8c0 mm/filemap.c:4242 shmem_file_write_iter+0xfb/0x120 mm/shmem.c:3464 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5d5/0xb40 fs/read_write.c:686 ksys_write+0x14b/0x260 fs/read_write.c:738 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: 0033:0x7fa985cdd97f Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48 RSP: 002b:00007fa983f3ddf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007fa985cdd97f RDX: 0000000001000000 RSI: 00007fa97bb1e000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000005e04 R10: 000020000000c742 R11: 0000000000000293 R12: 0000000000000003 R13: 00007fa983f3def0 R14: 00007fa983f3deb0 R15: 00007fa97bb1e000