INFO: task syz.2.191:7532 blocked for more than 143 seconds.
Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.191 state:D stack:26536 pid:7532 tgid:7503 ppid:5833 task_flags:0x400040 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
io_schedule+0x81/0xe0 kernel/sched/core.c:7742
folio_wait_bit_common+0x6b0/0xb90 mm/filemap.c:1317
folio_wait_writeback+0xb0/0x100 mm/page-writeback.c:3149
__filemap_fdatawait_range+0x147/0x230 mm/filemap.c:539
filemap_write_and_wait_range+0x25e/0x310 mm/filemap.c:700
bch2_extend fs/bcachefs/fs-io.c:407 [inline]
bchfs_truncate+0x57b/0xb70 fs/bcachefs/fs-io.c:460
notify_change+0xb33/0xe40 fs/attr.c:552
do_truncate+0x19a/0x220 fs/open.c:65
vfs_truncate+0x493/0x520 fs/open.c:115
do_sys_truncate+0xdb/0x190 fs/open.c:138
__do_sys_truncate fs/open.c:150 [inline]
__se_sys_truncate fs/open.c:148 [inline]
__x64_sys_truncate+0x5b/0x70 fs/open.c:148
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4b1c58e969
RSP: 002b:00007f4b1d45f038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007f4b1c7b6080 RCX: 00007f4b1c58e969
RDX: 0000000000000000 RSI: 000000000000bf39 RDI: 0000200000000900
RBP: 00007f4b1c610ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f4b1c7b6080 R15: 00007ffde10f35c8
</TASK>
INFO: task syz.2.191:7533 blocked for more than 143 seconds.
Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.191 state:D stack:28952 pid:7533 tgid:7503 ppid:5833 task_flags:0x400040 flags:0x00000004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x168f/0x4c70 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6860
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917
rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176
__down_write_common kernel/locking/rwsem.c:1304 [inline]
__down_write kernel/locking/rwsem.c:1313 [inline]
down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578
inode_lock include/linux/fs.h:867 [inline]
do_truncate+0x186/0x220 fs/open.c:63
vfs_truncate+0x493/0x520 fs/open.c:115
do_sys_truncate+0xdb/0x190 fs/open.c:138
__do_sys_truncate fs/open.c:150 [inline]
__se_sys_truncate fs/open.c:148 [inline]
__x64_sys_truncate+0x5b/0x70 fs/open.c:148
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4b1c58e969
RSP: 002b:00007f4b1d43e038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c
RAX: ffffffffffffffda RBX: 00007f4b1c7b6160 RCX: 00007f4b1c58e969
RDX: 0000000000000000 RSI: 000000000000bf39 RDI: 0000200000000900
RBP: 00007f4b1c610ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f4b1c7b6160 R15: 00007ffde10f35c8
</TASK>
Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
#0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline]
#0: ffffffff8df41338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998
1 lock held by khungtaskd/31:
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764
4 locks held by kworker/1:1H/60:
#0: ffff88802804ad48 ((wq_completion)bcachefs_btree_io#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88802804ad48 ((wq_completion)bcachefs_btree_io#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc9000136fc60 ((work_completion)(&wb->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000136fc60 ((work_completion)(&wb->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffff88804a684228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
#2: ffff88804a684228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
#2: ffff88804a684228 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x806/0xda0 fs/bcachefs/btree_iter.c:3385
#3: ffff88803a59c140 (bcachefs_btree){+.+.}-{0:0}, at: trans_set_locked fs/bcachefs/btree_locking.h:198 [inline]
#3: ffff88803a59c140 (bcachefs_btree){+.+.}-{0:0}, at: bch2_trans_begin+0xa60/0x1f10 fs/bcachefs/btree_iter.c:3282
1 lock held by dhcpcd/5484:
#0: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_deladdr+0x198/0x740 net/ipv4/devinet.c:671
2 locks held by getty/5569:
#0: ffff8880308820a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90002ffe2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by syz-executor/7295:
1 lock held by syz.2.191/7504:
#0: ffff88802981a420 (sb_writers#18){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline]
#0: ffff88802981a420 (sb_writers#18){.+.+}-{0:0}, at: vfs_writev+0x274/0x9a0 fs/read_write.c:1053
2 locks held by syz.2.191/7532:
#0: ffff88802981a420 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556
#1: ffff888078fe4d38 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
#1: ffff888078fe4d38 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: do_truncate+0x186/0x220 fs/open.c:63
2 locks held by syz.2.191/7533:
#0: ffff88802981a420 (sb_writers#18){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556
#1: ffff888078fe4d38 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline]
#1: ffff888078fe4d38 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: do_truncate+0x186/0x220 fs/open.c:63
2 locks held by bch-copygc/loop/7524:
3 locks held by kworker/u8:9/8868:
#0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801a089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc900047cfc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc900047cfc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
#2: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
2 locks held by kworker/u8:11/8870:
#0: ffff88801d36b948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801d36b948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319
#1: ffffc900044ffc60 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc900044ffc60 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319
2 locks held by syz.3.338/9186:
#0: ffff88802981a0e0 (&type->s_umount_key#56){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88802981a0e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
#1: ffff88802981a948 (&s->s_sync_lock){+.+.}-{4:4}, at: wait_sb_inodes fs/fs-writeback.c:2653 [inline]
#1: ffff88802981a948 (&s->s_sync_lock){+.+.}-{4:4}, at: sync_inodes_sb+0x255/0xa10 fs/fs-writeback.c:2836
2 locks held by syz.9.366/9597:
#0: ffff88802981a0e0 (&type->s_umount_key#56){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88802981a0e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
#1: ffff88802981a948 (&s->s_sync_lock){+.+.}-{4:4}, at: wait_sb_inodes fs/fs-writeback.c:2653 [inline]
#1: ffff88802981a948 (&s->s_sync_lock){+.+.}-{4:4}, at: sync_inodes_sb+0x255/0xa10 fs/fs-writeback.c:2836
3 locks held by syz-executor/9854:
2 locks held by syz-executor/9856:
#0: ffffffff8ea7bd20 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8ea7bd20 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8ea7bd20 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8f2e1508 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4064
2 locks held by syz.1.407/9997:
#0: ffff88802981a0e0 (&type->s_umount_key#56){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88802981a0e0 (&type->s_umount_key#56){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:120
#1: ffff88802981a948 (&s->s_sync_lock){+.+.}-{4:4}, at: wait_sb_inodes fs/fs-writeback.c:2653 [inline]
#1: ffff88802981a948 (&s->s_sync_lock){+.+.}-{4:4}, at: sync_inodes_sb+0x255/0xa10 fs/fs-writeback.c:2836
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
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:274 [inline]
watchdog+0xfee/0x1030 kernel/hung_task.c:437
kthread+0x70e/0x8a0 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
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: 9854 Comm: syz-executor Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:next_tid mm/slub.c:3020 [inline]
RIP: 0010:__update_cpu_freelist_fast mm/slub.c:3617 [inline]
RIP: 0010:__slab_alloc_node mm/slub.c:4055 [inline]
RIP: 0010:slab_alloc_node mm/slub.c:4198 [inline]
RIP: 0010:__kmalloc_cache_noprof+0xec/0x3d0 mm/slub.c:4367
Code: 00 00 41 83 fc ff 74 1a 48 8b 03 48 83 f8 ff 0f 84 e3 02 00 00 48 c1 e8 3a 41 39 c4 0f 85 73 01 00 00 41 8b 47 28 4a 8b 1c 28 <49> 8d 4e 08 49 8b 37 4c 89 e8 4c 89 f2 65 48 0f c7 0e 74 5c eb 95
RSP: 0018:ffffc90005036af0 EFLAGS: 00000246
RAX: 0000000000000800 RBX: 0000000000000000 RCX: ffffffff9273bf20
RDX: 0000000000000000 RSI: 0000000000001000 RDI: ffffffff8e05aca0
RBP: 0000000000000dc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff82128bed R12: 00000000ffffffff
R13: ffff88805b15a000 R14: 00000000002d1fe1 R15: ffff88801a042140
FS: 000055555eb42500(0000) GS:ffff888126202000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556fc73608 CR3: 0000000062f9a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1039 [inline]
kobject_uevent_env+0x27c/0x8c0 lib/kobject_uevent.c:540
device_add+0x557/0xb50 drivers/base/core.c:3673
netdev_register_kobject+0x156/0x2f0 net/core/net-sysfs.c:2336
register_netdevice+0x126c/0x1af0 net/core/dev.c:11009
veth_newlink+0x5cc/0xa50 drivers/net/veth.c:1847
rtnl_newlink_create+0x305/0xaf0 net/core/rtnetlink.c:3833
__rtnl_newlink net/core/rtnetlink.c:3950 [inline]
rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4065
rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6955
netlink_rcv_skb+0x219/0x490 net/netlink/af_netlink.c:2534
netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg+0x219/0x270 net/socket.c:727
__sys_sendto+0x3bd/0x520 net/socket.c:2180
__do_sys_sendto net/socket.c:2187 [inline]
__se_sys_sendto net/socket.c:2183 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2183
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f740e3907fc
Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b
RSP: 002b:00007ffe9824cb90 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f740f0e4620 RCX: 00007f740e3907fc
RDX: 0000000000000064 RSI: 00007f740f0e4670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffe9824cbe4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f740f0e4670 R15: 0000000000000000
</TASK>