INFO: task syz.8.101:8648 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.101 state:D stack:21960 pid:8648 ppid:8559 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 io_schedule+0x7c/0xd0 kernel/sched/core.c:8797 __lock_metapage fs/jfs/jfs_metapage.c:50 [inline] lock_metapage+0x1e8/0x310 fs/jfs/jfs_metapage.c:64 __get_metapage+0x4c6/0xfa0 fs/jfs/jfs_metapage.c:639 xtSplitPage+0x238/0x1c10 fs/jfs/jfs_xtree.c:974 xtSplitUp+0x293/0x1c20 fs/jfs/jfs_xtree.c:771 xtInsert+0x455/0xbb0 fs/jfs/jfs_xtree.c:593 extAlloc+0x9f6/0xf30 fs/jfs/jfs_extent.c:145 jfs_get_block+0x343/0xab0 fs/jfs/inode.c:254 __block_write_begin_int+0x54b/0x1a70 fs/buffer.c:1991 __block_write_begin fs/buffer.c:2041 [inline] block_write_begin+0x96/0x1e0 fs/buffer.c:2102 jfs_write_begin+0x31/0x70 fs/jfs/inode.c:310 generic_perform_write+0x2f7/0x5a0 mm/filemap.c:3862 __generic_file_write_iter+0x148/0x2a0 mm/filemap.c:3960 generic_file_write_iter+0xab/0x2e0 mm/filemap.c:3989 __kernel_write_iter+0x26d/0x630 fs/read_write.c:517 dump_emit_page fs/coredump.c:950 [inline] dump_user_range+0x3ea/0x7f0 fs/coredump.c:977 elf_core_dump+0x2f77/0x3490 fs/binfmt_elf.c:2354 do_coredump+0x15ff/0x22b0 fs/coredump.c:824 get_signal+0x10aa/0x1350 kernel/signal.c:2857 arch_do_signal_or_restart+0xb7/0x1240 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:316 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1490 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f7a50d8f751 RSP: 002b:00000000fffffe60 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f7a50fe5fa0 RCX: 00007f7a50d8f749 RDX: 0000000000000000 RSI: 00000000fffffe60 RDI: 0000000000040000 RBP: 00007f7a50e13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f7a50fe5fa0 R14: 00007f7a50fe5fa0 R15: 0000000000000006 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8c92bab0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8c92c2d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/28: #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 1 lock held by dhcpcd/3932: 2 locks held by getty/4026: #0: ffff88814d3c9098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 4 locks held by syz.8.101/8648: #0: ffff8880186d6460 (sb_writers#13){.+.+}-{0:0}, at: do_coredump+0x15de/0x22b0 fs/coredump.c:823 #1: ffff888069b32a80 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff888069b32a80 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: generic_file_write_iter+0x7f/0x2e0 mm/filemap.c:3986 #2: ffff888069b32638 (&jfs_ip->rdwrlock#2){+.+.}-{3:3}, at: jfs_get_block+0x13e/0xab0 fs/jfs/inode.c:219 #3: ffff888069b326c8 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: extAlloc+0x10b/0xf30 fs/jfs/jfs_extent.c:81 3 locks held by syz.8.246/12020: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3932 Comm: dhcpcd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:clear_page_erms+0x7/0x10 arch/x86/lib/clear_page_64.S:50 Code: 48 89 47 18 48 89 47 20 48 89 47 28 48 89 47 30 48 89 47 38 48 8d 7f 40 75 d9 90 c3 90 90 90 90 90 90 90 b9 00 10 00 00 31 c0 aa c3 90 90 90 90 90 90 89 c8 48 c1 e9 03 74 18 0f 1f 84 00 00 RSP: 0018:ffffc90003707338 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000f80 RDX: ffff888077340000 RSI: 0000000000000001 RDI: ffff888077340080 RBP: 0000000000112cc0 R08: dffffc0000000000 R09: ffffed100ee68000 R10: fffff940003b9a07 R11: 1ffffd40003b9a06 R12: 0000000000000001 R13: 0000000000000000 R14: ffffea0001dcd000 R15: 0000000000000001 FS: 00007faeb8e6a740(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb0a7729000 CR3: 000000001d72f000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: clear_page arch/x86/include/asm/page_64.h:58 [inline] clear_highpage include/linux/highmem.h:242 [inline] clear_highpage_kasan_tagged include/linux/highmem.h:252 [inline] kernel_init_pages mm/page_alloc.c:1381 [inline] post_alloc_hook+0x12c/0x1a0 mm/page_alloc.c:2527 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614 alloc_slab_page+0x5d/0x160 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2c0 mm/slub.c:1997 ___slab_alloc+0xbc6/0x1230 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] kmem_cache_alloc_node+0x1e5/0x320 mm/slub.c:3404 __alloc_skb+0xfc/0x7e0 net/core/skbuff.c:505 alloc_skb include/linux/skbuff.h:1271 [inline] alloc_skb_with_frags+0xa7/0x710 net/core/skbuff.c:6162 sock_alloc_send_pskb+0x853/0x980 net/core/sock.c:2755 unix_dgram_sendmsg+0x592/0x16c0 net/unix/af_unix.c:1945 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] sock_write_iter+0x2b5/0x3a0 net/socket.c:1143 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x44c/0x960 fs/read_write.c:584 ksys_write+0x143/0x240 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7faeb8ef4407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffc51e494d0 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007faeb8e6a740 RCX: 00007faeb8ef4407 RDX: 000000000000003b RSI: 00007ffc51e49530 RDI: 0000000000000005 RBP: 00005613f81f5168 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffc51e49960 R13: 0000561404d4bec0 R14: 0000561404be6790 R15: 0000561404da19d0