syzbot

INFO: task syz.4.21:6077 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.21        state:D stack:27800 pid:6077  tgid:6077  ppid:5954   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x10e9/0x6820 kernel/sched/core.c:7188
 __schedule_loop kernel/sched/core.c:7267 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7282
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7339
 rwsem_down_write_slowpath+0x4c2/0x12c0 kernel/locking/rwsem.c:1215
 __down_write_common kernel/locking/rwsem.c:1347 [inline]
 __down_write kernel/locking/rwsem.c:1356 [inline]
 down_write+0x1c7/0x1f0 kernel/locking/rwsem.c:1626
 inode_lock include/linux/fs.h:1029 [inline]
 blkdev_fallocate+0x24b/0x440 block/fops.c:907
 vfs_fallocate+0x576/0x10d0 fs/open.c:338
 ksys_fallocate fs/open.c:362 [inline]
 __do_sys_fallocate fs/open.c:367 [inline]
 __se_sys_fallocate fs/open.c:365 [inline]
 __x64_sys_fallocate+0xd5/0x140 fs/open.c:365
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f569c59c819
RSP: 002b:00007fffa5647e18 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007f569c815fa0 RCX: 00007f569c59c819
RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000000000000004
RBP: 00007f569c632c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000002000000400 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f569c815fac R14: 00007f569c815fa0 R15: 00007f569c815fa0
 </TASK>
INFO: task syz.2.19:6078 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.19        state:D stack:27800 pid:6078  tgid:6078  ppid:5945   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x10e9/0x6820 kernel/sched/core.c:7188
 __schedule_loop kernel/sched/core.c:7267 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7282
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7339
 rwsem_down_write_slowpath+0x4c2/0x12c0 kernel/locking/rwsem.c:1215
 __down_write_common kernel/locking/rwsem.c:1347 [inline]
 __down_write kernel/locking/rwsem.c:1356 [inline]
 down_write+0x1c7/0x1f0 kernel/locking/rwsem.c:1626
 inode_lock include/linux/fs.h:1029 [inline]
 blkdev_fallocate+0x24b/0x440 block/fops.c:907
 vfs_fallocate+0x576/0x10d0 fs/open.c:338
 ksys_fallocate fs/open.c:362 [inline]
 __do_sys_fallocate fs/open.c:367 [inline]
 __se_sys_fallocate fs/open.c:365 [inline]
 __x64_sys_fallocate+0xd5/0x140 fs/open.c:365
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7710f9c819
RSP: 002b:00007ffc63336d48 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007f7711215fa0 RCX: 00007f7710f9c819
RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000000000000004
RBP: 00007f7711032c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000002000000400 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7711215fac R14: 00007f7711215fa0 R15: 00007f7711215fa0
 </TASK>
INFO: task syz.0.17:6079 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:27784 pid:6079  tgid:6079  ppid:5939   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x10e9/0x6820 kernel/sched/core.c:7188
 __schedule_loop kernel/sched/core.c:7267 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7282
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7339
 rwsem_down_write_slowpath+0x4c2/0x12c0 kernel/locking/rwsem.c:1215
 __down_write_common kernel/locking/rwsem.c:1347 [inline]
 __down_write kernel/locking/rwsem.c:1356 [inline]
 down_write+0x1c7/0x1f0 kernel/locking/rwsem.c:1626
 inode_lock include/linux/fs.h:1029 [inline]
 blkdev_fallocate+0x24b/0x440 block/fops.c:907
 vfs_fallocate+0x576/0x10d0 fs/open.c:338
 ksys_fallocate fs/open.c:362 [inline]
 __do_sys_fallocate fs/open.c:367 [inline]
 __se_sys_fallocate fs/open.c:365 [inline]
 __x64_sys_fallocate+0xd5/0x140 fs/open.c:365
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f00e559c819
RSP: 002b:00007ffd0d989a48 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007f00e5815fa0 RCX: 00007f00e559c819
RDX: 0000000000000000 RSI: 0000000000000010 RDI: 0000000000000004
RBP: 00007f00e5632c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000002000000400 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f00e5815fac R14: 00007f00e5815fa0 R15: 00007f00e5815fa0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e7e5460 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8e7e5460 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e7e5460 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by getty/5570:
 #0: ffff88803a5780a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211
2 locks held by syz.1.18/6076:
1 lock held by syz.4.21/6077:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.2.19/6078:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.0.17/6079:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.7.24/6220:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.6.23/6221:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.9.26/6222:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.5.22/6223:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.8.25/6224:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.0.27/6315:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.1.28/6316:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.2.29/6321:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.3.30/6332:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.4.31/6333:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.6.32/6457:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.7.33/6459:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.5.34/6470:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.9.36/6472:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.8.35/6473:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.0.37/6561:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.1.38/6562:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.2.39/6582:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.3.40/6583:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.4.41/6584:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.6.42/6684:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.7.43/6697:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.8.45/6718:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.9.46/6719:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.5.44/6720:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.0.47/6800:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.1.48/6822:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.2.49/6829:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.3.50/6834:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907
1 lock held by syz.4.51/6835:
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888027d41360 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:907

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xcb1/0x1030 kernel/hung_task.c:561
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: d6 88 02 e9 83 42 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 23 b0 13 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df0 EFLAGS: 00000242
RAX: 000000000016cc19 RBX: ffff88801e6f2500 RCX: ffffffff8b97e045
RDX: 0000000000000000 RSI: ffffffff8df53c55 RDI: ffffffff8c1c0e00
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10170a67ad
R10: ffff8880b8533d6b R11: 0000000000000000 R12: 0000000000000001
R13: ffffed1003cde4a0 R14: 0000000000000001 R15: ffffffff90dbba50
FS:  0000000000000000(0000) GS:ffff8881243ef000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556065a4e8 CR3: 0000000070655000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
 default_idle+0x9/0x10 arch/x86/kernel/process.c:767
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x464/0x590 kernel/sched/idle.c:352
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451
 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x148
 </TASK>