INFO: task syz.8.1305:13423 blocked for more than 143 seconds. Not tainted 5.15.178-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.1305 state:D stack:22776 pid:13423 ppid: 12750 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 rwsem_down_write_slowpath+0xf0c/0x16a0 kernel/locking/rwsem.c:1165 inode_lock_nested include/linux/fs.h:824 [inline] filename_create+0x25c/0x530 fs/namei.c:3835 do_mkdirat+0xb3/0x520 fs/namei.c:4080 __do_sys_mkdirat fs/namei.c:4105 [inline] __se_sys_mkdirat fs/namei.c:4103 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4103 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f5426e829d7 RSP: 002b:00007f5424cece68 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f5424cecef0 RCX: 00007f5426e829d7 RDX: 00000000000001ff RSI: 00004000000001c0 RDI: 00000000ffffff9c RBP: 0000400000000240 R08: 00004000000001c0 R09: 0000000000000000 R10: 0000400000000240 R11: 0000000000000246 R12: 00004000000001c0 R13: 00007f5424ceceb0 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8cb1fce0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 3 locks held by kworker/0:2/2238: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc900065ffd20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff8cb242a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #2: ffffffff8cb242a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x350/0x740 kernel/rcu/tree_exp.h:845 2 locks held by udevd/3547: #0: ffff888020d28518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xfb/0x790 block/bdev.c:912 #1: ffff8881476b7468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2070 2 locks held by getty/3932: #0: ffff88802b72a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cd62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158 2 locks held by kworker/0:4/4211: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc9000303fd20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 2 locks held by syz.8.1305/13423: #0: ffff888062fba460 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:377 #1: ffff8880622837e0 (&type->i_mutex_dir_key#12/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:824 [inline] #1: ffff8880622837e0 (&type->i_mutex_dir_key#12/1){+.+.}-{3:3}, at: filename_create+0x25c/0x530 fs/namei.c:3835 3 locks held by syz.8.1305/13430: 1 lock held by syz-executor/13988: #0: ffffffff8cb242a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #0: ffffffff8cb242a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:845 2 locks held by syz-executor/15380: #0: ffff888020d26118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xfb/0x790 block/bdev.c:912 #1: ffff8881476b1468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xa9/0xbe0 drivers/block/loop.c:1365 1 lock held by syz.6.1665/16375: #0: ffff888020d28518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x14d/0xa50 block/bdev.c:817 2 locks held by dhcpcd-run-hook/16412: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.178-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xe72/0xeb0 kernel/hung_task.c:295 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 16375 Comm: syz.6.1665 Not tainted 5.15.178-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:memset+0x2d/0x40 mm/kasan/shadow.c:47 Code: 53 48 89 d3 41 89 f6 48 89 fd 48 8b 4c 24 18 48 89 d6 ba 01 00 00 00 e8 31 ef ff ff 84 c0 74 12 48 89 ef 44 89 f6 48 89 da 5b <41> 5e 5d e9 5b 05 72 02 31 c0 5b 41 5e 5d c3 0f 1f 40 00 41 57 41 RSP: 0018:ffffc90003f3f110 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffc90003f3f230 RCX: ffffffff8138b4b8 RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc90003f3f230 RBP: ffffc90003f3f230 R08: dffffc0000000000 R09: fffff520007e7e48 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff1d14613 R13: 1ffffffff1d14613 R14: 0000000000000000 R15: ffffc90003f3f1e0 FS: 00007f1ccda816c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc26d78b98 CR3: 000000007604e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000008e5c DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0xbc8/0x1fa0 arch/x86/kernel/unwind_orc.c:547 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122 save_stack+0xf6/0x1e0 mm/page_owner.c:119 __reset_page_owner+0x52/0x180 mm/page_owner.c:140 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433 release_pages+0x1bb9/0x1f40 mm/swap.c:963 __pagevec_release+0x80/0xf0 mm/swap.c:983 pagevec_release include/linux/pagevec.h:81 [inline] shmem_undo_range+0x67a/0x1b50 mm/shmem.c:964 shmem_truncate_range mm/shmem.c:1063 [inline] shmem_evict_inode+0x21b/0xa00 mm/shmem.c:1145 evict+0x529/0x930 fs/inode.c:622 __dentry_kill+0x436/0x650 fs/dcache.c:586 dentry_kill+0xbb/0x290 dput+0xd8/0x1a0 fs/dcache.c:893 __fput+0x636/0x8e0 fs/file_table.c:288 task_work_run+0x129/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f1ccfc17d6b Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00 RSP: 002b:00007f1ccda80e10 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: ffffffffffffffff RCX: 00007f1ccfc17d6b RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000008 RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000510006 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000016 R13: 00007f1ccda80eb0 R14: 00000000000061e3 R15: 0000400000000140