INFO: task syz.0.17:4352 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:29008 pid: 4352 ppid: 4294 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 rwsem_down_write_slowpath+0xc46/0x11f0 kernel/locking/rwsem.c:1165 inode_lock include/linux/fs.h:787 [inline] ntfs_fallocate+0x1a9/0xcc0 fs/ntfs3/file.c:558 vfs_fallocate+0x587/0x6f0 fs/open.c:308 ksys_fallocate fs/open.c:331 [inline] __do_sys_fallocate fs/open.c:339 [inline] __se_sys_fallocate fs/open.c:337 [inline] __x64_sys_fallocate+0xbd/0x100 fs/open.c:337 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ff7660e3749 RSP: 002b:00007ff765731038 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007ff76633a090 RCX: 00007ff7660e3749 RDX: 000000000000000a RSI: 0000000000000001 RDI: 0000000000000006 RBP: 00007ff766167f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000009 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff76633a128 R14: 00007ff76633a090 R15: 00007fff274ae3b8 Showing all locks held in the system: 2 locks held by kworker/u4:0/9: 1 lock held by khungtaskd/27: #0: ffffffff8c11c720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3945: #0: ffff88802ba54098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 4 locks held by syz.0.17/4351: 2 locks held by syz.0.17/4352: #0: ffff88807be24460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3043 [inline] #0: ffff88807be24460 (sb_writers#13){.+.+}-{0:0}, at: vfs_fallocate+0x4f4/0x6f0 fs/open.c:307 #1: ffff88805cdb03a0 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #1: ffff88805cdb03a0 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: ntfs_fallocate+0x1a9/0xcc0 fs/ntfs3/file.c:558 3 locks held by syz.1.18/4376: 2 locks held by syz.1.18/4378: #0: ffff88801a396460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3043 [inline] #0: ffff88801a396460 (sb_writers#13){.+.+}-{0:0}, at: vfs_fallocate+0x4f4/0x6f0 fs/open.c:307 #1: ffff88805cdb79a0 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #1: ffff88805cdb79a0 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: ntfs_fallocate+0x1a9/0xcc0 fs/ntfs3/file.c:558 4 locks held by syz.2.19/4408: 2 locks held by syz.2.19/4409: #0: ffff888025000460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3043 [inline] #0: ffff888025000460 (sb_writers#13){.+.+}-{0:0}, at: vfs_fallocate+0x4f4/0x6f0 fs/open.c:307 #1: ffff88806ef2f240 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #1: ffff88806ef2f240 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: ntfs_fallocate+0x1a9/0xcc0 fs/ntfs3/file.c:558 4 locks held by syz.3.20/4430: 2 locks held by syz.3.20/4431: #0: ffff88801a7e4460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3043 [inline] #0: ffff88801a7e4460 (sb_writers#13){.+.+}-{0:0}, at: vfs_fallocate+0x4f4/0x6f0 fs/open.c:307 #1: ffff88805ccfeae0 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #1: ffff88805ccfeae0 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: ntfs_fallocate+0x1a9/0xcc0 fs/ntfs3/file.c:558 4 locks held by syz.4.21/4461: 2 locks held by syz.4.21/4462: #0: ffff888075186460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3043 [inline] #0: ffff888075186460 (sb_writers#13){.+.+}-{0:0}, at: vfs_fallocate+0x4f4/0x6f0 fs/open.c:307 #1: ffff88805cdb3740 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #1: ffff88805cdb3740 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: ntfs_fallocate+0x1a9/0xcc0 fs/ntfs3/file.c:558 3 locks held by syz.5.22/4497: 2 locks held by syz.5.22/4498: #0: ffff88805cb00460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3043 [inline] #0: ffff88805cb00460 (sb_writers#13){.+.+}-{0:0}, at: vfs_fallocate+0x4f4/0x6f0 fs/open.c:307 #1: ffff88806ef51260 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #1: ffff88806ef51260 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: ntfs_fallocate+0x1a9/0xcc0 fs/ntfs3/file.c:558 4 locks held by syz.6.23/4528: 2 locks held by syz.6.23/4529: #0: ffff88805b1b4460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3043 [inline] #0: ffff88805b1b4460 (sb_writers#13){.+.+}-{0:0}, at: vfs_fallocate+0x4f4/0x6f0 fs/open.c:307 #1: ffff88805cdb1260 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #1: ffff88805cdb1260 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: ntfs_fallocate+0x1a9/0xcc0 fs/ntfs3/file.c:558 4 locks held by syz.7.24/4563: 2 locks held by syz.7.24/4564: #0: ffff88807bbf8460 (sb_writers#13){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3043 [inline] #0: ffff88807bbf8460 (sb_writers#13){.+.+}-{0:0}, at: vfs_fallocate+0x4f4/0x6f0 fs/open.c:307 #1: ffff88806ef54600 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #1: ffff88806ef54600 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: ntfs_fallocate+0x1a9/0xcc0 fs/ntfs3/file.c:558 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 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+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4351 Comm: syz.0.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline] RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:331 [inline] RIP: 0010:rcu_is_watching+0x56/0xa0 kernel/rcu/tree.c:1123 Code: f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 40 83 58 00 48 c7 c3 08 b3 03 00 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 <84> c0 75 2b 8b 03 65 ff 0d 35 be 9e 7e 74 08 24 01 5b 41 5e 41 5f RSP: 0018:ffffc9000308f700 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: ffff8880b903b308 RCX: 2576037c3ff0f300 RDX: 0000000000000000 RSI: ffffffff8a59e7e0 RDI: ffffffff8a59e7a0 RBP: ffffc9000308f830 R08: dffffc0000000000 R09: fffffbfff1ad26b6 R10: fffffbfff1ad26b6 R11: 1ffffffff1ad26b5 R12: ffff88805cdb01b0 R13: 1ffff92000611ef0 R14: ffffffff8bbc0820 R15: dffffc0000000000 FS: 00007ff7657526c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055bffcdbca38 CR3: 00000000753a4000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0xcd/0x3f0 kernel/locking/lockdep.c:5594 down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498 attr_data_get_block+0x10d/0x1880 fs/ntfs3/attrib.c:831 ntfs_compress_write+0x6fe/0x1c30 fs/ntfs3/file.c:929 ntfs_file_write_iter+0x3d7/0x590 fs/ntfs3/file.c:1146 call_write_iter include/linux/fs.h:2173 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x712/0xd00 fs/read_write.c:594 ksys_write+0x14d/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ff7660e3749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff765752038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ff766339fa0 RCX: 00007ff7660e3749 RDX: 0000000000000020 RSI: 0000200000000980 RDI: 0000000000000006 RBP: 00007ff766167f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff76633a038 R14: 00007ff766339fa0 R15: 00007fff274ae3b8