syzbot

INFO: task syz-executor405:5830 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor405 state:D stack:16056 pid:5830  tgid:5829  ppid:5828   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 io_schedule+0x81/0xe0 kernel/sched/core.c:7723
 folio_wait_bit_common+0x6b0/0xb90 mm/filemap.c:1317
 folio_lock include/linux/pagemap.h:1114 [inline]
 invalidate_inode_pages2_range+0x557/0xa80 mm/truncate.c:690
 bch2_write_invalidate_inode_pages_range+0xc5/0x110 fs/bcachefs/fs-io-pagecache.c:68
 bch2_direct_write+0x2a62/0x2ce0 fs/bcachefs/fs-io-direct.c:662
 bch2_write_iter+0x18f/0x2b90 fs/bcachefs/fs-io-buffered.c:1064
 iter_file_splice_write+0x937/0x1000 fs/splice.c:738
 do_splice_from fs/splice.c:935 [inline]
 direct_splice_actor+0x101/0x160 fs/splice.c:1158
 splice_direct_to_actor+0x5a5/0xcc0 fs/splice.c:1102
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0x181/0x270 fs/splice.c:1227
 do_sendfile+0x4da/0x7e0 fs/read_write.c:1370
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64+0x13e/0x190 fs/read_write.c:1417
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4daeaa3509
RSP: 002b:00007f4daea58218 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f4daeb30608 RCX: 00007f4daeaa3509
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000005
RBP: 00007f4daeb30600 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000800000009 R11: 0000000000000246 R12: 00007f4daeafcb48
R13: 0031656c69662f2e R14: 0000200000000240 R15: 0000200000000040
 </TASK>
INFO: task syz-executor405:5842 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc2-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor405 state:D stack:24392 pid:5842  tgid:5829  ppid:5828   task_flags:0x440040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 __bch2_two_state_lock+0x1ea/0x370 fs/bcachefs/two_state_shared_lock.c:7
 bch2_two_state_lock fs/bcachefs/two_state_shared_lock.h:55 [inline]
 bch2_readahead+0x94f/0x1100 fs/bcachefs/fs-io-buffered.c:296
 read_pages+0x17a/0x580 mm/readahead.c:160
 page_cache_ra_order+0xa24/0xc70 mm/readahead.c:515
 filemap_get_pages+0x43c/0x1ea0 mm/filemap.c:2602
 filemap_splice_read+0x4fc/0xbc0 mm/filemap.c:2990
 do_splice_read fs/splice.c:979 [inline]
 splice_direct_to_actor+0x4a6/0xcc0 fs/splice.c:1083
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0x181/0x270 fs/splice.c:1227
 do_sendfile+0x4da/0x7e0 fs/read_write.c:1370
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64+0x13e/0x190 fs/read_write.c:1417
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4daeaa3509
RSP: 002b:00007f4daea37218 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f4daeb30618 RCX: 00007f4daeaa3509
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000006
RBP: 00007f4daeb30610 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000e3aa6ea R11: 0000000000000246 R12: 00007f4daeafcb48
R13: 0031656c69662f2e R14: 0000200000000240 R15: 0000200000000040
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e13ed60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13ed60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13ed60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5584:
 #0: ffff88814dc680a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor405/5830:
 #0: ffff888034a78428 (sb_writers#8){.+.+}-{0:0}, at: direct_splice_actor+0x49/0x160 fs/splice.c:1157
1 lock held by syz-executor405/5842:
 #0: ffff88806c5982e8 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline]
 #0: ffff88806c5982e8 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: page_cache_ra_order+0x445/0xc70 mm/readahead.c:491

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc2-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 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:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:470
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-rc2-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: cc cc cc cc cc cc cc 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 f6 28 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c6
RAX: 0c7705bb82258100 RBX: ffffffff81975c68 RCX: 0c7705bb82258100
RDX: 0000000000000001 RSI: ffffffff8d96e7d3 RDI: ffffffff8be1b680
RBP: ffffffff8de07ea8 R08: ffff8880b8632f5b R09: 1ffff110170c65eb
R10: dffffc0000000000 R11: ffffed10170c65ec R12: ffffffff8f9fe2f0
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a50
FS:  0000000000000000(0000) GS:ffff888125c85000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055ed86da7660 CR3: 000000000df38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:749
 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x1e8/0x510 kernel/sched/idle.c:325
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423
 rest_init+0x2de/0x300 init/main.c:745
 start_kernel+0x47d/0x500 init/main.c:1102
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307
 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288
 common_startup_64+0x13e/0x147
 </TASK>