INFO: task syz.4.52:6293 blocked for more than 143 seconds.
Not tainted 6.14.0-rc5-syzkaller-00023-gbb2281fb05e5 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.52 state:D stack:27552 pid:6293 tgid:6265 ppid:5840 task_flags:0x400040 flags:0x00000004
Call Trace:
context_switch kernel/sched/core.c:5378 [inline]
__schedule+0x18bc/0x4c40 kernel/sched/core.c:6765
__schedule_loop kernel/sched/core.c:6842 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6857
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914
rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1176
__down_write_common kernel/locking/rwsem.c:1304 [inline]
__down_write kernel/locking/rwsem.c:1313 [inline]
down_write_nested+0x1e0/0x220 kernel/locking/rwsem.c:1694
inode_lock_nested include/linux/fs.h:912 [inline]
do_unlinkat+0x26a/0x830 fs/namei.c:4576
__do_sys_unlink fs/namei.c:4637 [inline]
__se_sys_unlink fs/namei.c:4635 [inline]
__x64_sys_unlink+0x47/0x50 fs/namei.c:4635
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f82fed8d169
RSP: 002b:00007f82ffba7038 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 00007f82fefa6160 RCX: 00007f82fed8d169
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000400000000300
RBP: 00007f82fee0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f82fefa6160 R15: 00007ffdd40e2838
Showing all locks held in the system:
4 locks held by kworker/u8:0/11:
#0: ffff8880206bb148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff8880206bb148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319
#1: ffffc90000107c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc90000107c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319
#2: ffff88807f74a0e0 (&type->s_umount_key#83){++++}-{4:4}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562
#3: ffff8880552aafe0 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x24a/0x590 fs/jfs/inode.c:102
1 lock held by khungtaskd/30:
#0: ffffffff8eb392e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#0: ffffffff8eb392e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8eb392e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746
3 locks held by kworker/u8:4/63:
#0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
#0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319
#1: ffffc9000214fc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
#1: ffffc9000214fc60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319
#2: ffffffff8fec3708 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:285
7 locks held by kworker/u8:5/1141:
4 locks held by kworker/u8:6/1160:
2 locks held by kworker/u8:7/2910:
1 lock held by syslogd/5179:
1 lock held by dhcpcd/5491:
#0: ffffffff8fec3708 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline]
#0: ffffffff8fec3708 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_deladdr+0x241/0x360 net/ipv6/addrconf.c:4795
2 locks held by getty/5580:
#0: ffff8880360120a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211
4 locks held by syz.4.52/6286:
2 locks held by syz.4.52/6293:
#0: ffff88807f74a420 (sb_writers#22){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:547
#1: ffff8880552ab390 (&type->i_mutex_dir_key#19/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:912 [inline]
#1: ffff8880552ab390 (&type->i_mutex_dir_key#19/1){+.+.}-{4:4}, at: do_unlinkat+0x26a/0x830 fs/namei.c:4576
2 locks held by syz.8.127/7177:
#0: ffff88807f74a0e0 (&type->s_umount_key#83){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88807f74a0e0 (&type->s_umount_key#83){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120
#1: ffff888025f927d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff888025f927d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819
2 locks held by syz-executor/8461:
#0: ffffffff8f6714e0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#0: ffffffff8f6714e0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8f6714e0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x22/0x250 net/core/rtnetlink.c:564
#1: ffffffff8fec3708 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline]
#1: ffffffff8fec3708 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:335 [inline]
#1: ffffffff8fec3708 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc55/0x1d30 net/core/rtnetlink.c:4021
2 locks held by syz.4.246/8578:
2 locks held by syz.1.245/8577:
#0: ffff88807f7340e0 (&type->s_umount_key#49/1){+.+.}-{4:4}, at: alloc_super+0x221/0x9d0 fs/super.c:344
#1: ffffffff8e9e4408 (wq_pool_mutex){+.+.}-{4:4}, at: apply_wqattrs_lock kernel/workqueue.c:5179 [inline]
#1: ffffffff8e9e4408 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0x9ee/0x1bb0 kernel/workqueue.c:5734
2 locks held by syz.3.247/8582:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc5-syzkaller-00023-gbb2281fb05e5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
watchdog+0x1058/0x10a0 kernel/hung_task.c:399
kthread+0x7a9/0x920 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5179 Comm: syslogd Not tainted 6.14.0-rc5-syzkaller-00023-gbb2281fb05e5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:__sanitizer_cov_trace_switch+0x109/0x120 kernel/kcov.c:352
Code: e3 48 c1 e3 05 48 8d 43 28 4c 39 f8 77 a3 49 ff c4 4c 89 21 4c 89 44 0b 08 4c 89 74 0b 10 48 89 7c 0b 18 4c 89 4c 0b 20 eb 87 <5b> 41 5c 41 5e 41 5f c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc90003177950 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88807d555a00
RDX: 0000000000000002 RSI: ffffffff8feb3920 RDI: 0000000000000000
RBP: ffffc90003177b28 R08: 0000000000000005 R09: ffffffff89bafd99
R10: 0000000000000002 R11: ffff88807d555a00 R12: dffffc0000000000
R13: 1ffff9200062ef44 R14: 0000000000000001 R15: ffff888020fb9500
FS: 00007f0a380ba380(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fcceffff000 CR3: 000000003584e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
kfree_skbmem+0x49/0x1c0 net/core/skbuff.c:1056
__unix_dgram_recvmsg+0xcf5/0x1320 net/unix/af_unix.c:2515
sock_recvmsg_nosec net/socket.c:1023 [inline]
sock_recvmsg+0x22f/0x280 net/socket.c:1045
sock_read_iter+0x2c4/0x3d0 net/socket.c:1115
new_sync_read fs/read_write.c:484 [inline]
vfs_read+0x975/0xb40 fs/read_write.c:565
ksys_read+0x18f/0x2b0 fs/read_write.c:708
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0a3820eb6a
Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83
RSP: 002b:00007fff54400338 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f0a3820eb6a
RDX: 00000000000000ff RSI: 0000558b98f5e950 RDI: 0000000000000000
RBP: 0000558b98f5e910 R08: 0000000000000001 R09: 0000000000000000
R10: 00007f0a383ad3a3 R11: 0000000000000246 R12: 0000558b98f5e99b
R13: 0000558b98f5e950 R14: 0000000000000000 R15: 00007f0a383f1a80