INFO: task syz.3.226:7182 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.226 state:D stack:27216 pid:7182 ppid:5777 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
rwsem_down_read_slowpath+0x4f8/0x840 kernel/locking/rwsem.c:1086
__down_read_common kernel/locking/rwsem.c:1250 [inline]
__down_read kernel/locking/rwsem.c:1263 [inline]
down_read+0x98/0x2e0 kernel/locking/rwsem.c:1522
__super_lock fs/super.c:58 [inline]
super_lock+0x167/0x360 fs/super.c:117
super_lock_shared fs/super.c:146 [inline]
iterate_supers+0x80/0x170 fs/super.c:977
quota_sync_all fs/quota/quota.c:69 [inline]
__do_sys_quotactl fs/quota/quota.c:938 [inline]
__se_sys_quotactl+0x355/0x950 fs/quota/quota.c:917
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f26a238f749
RSP: 002b:00007f26a05d5038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f26a25e6090 RCX: 00007f26a238f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000100
RBP: 00007f26a2413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f26a25e6128 R14: 00007f26a25e6090 R15: 00007ffe987173d8
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/u4:3/49:
#0: ffff888141eda138 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888141eda138 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90000ba7d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90000ba7d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
2 locks held by getty/5530:
#0: ffff88814ca860a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000327e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
2 locks held by kworker/1:5/5863:
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900049afd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900049afd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
1 lock held by syz.1.214/7106:
#0: ffff88805e4080e0 (&type->s_umount_key#97/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x920 fs/super.c:352
1 lock held by syz.3.226/7182:
#0: ffff88805e4080e0 (&type->s_umount_key#120){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88805e4080e0 (&type->s_umount_key#120){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117
1 lock held by syz-executor/7244:
1 lock held by syz-executor/7388:
#0: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#0: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004
1 lock held by syz.5.309/7817:
#0: ffffffff8cd357c0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:4089
1 lock held by syz.9.467/8625:
#0: ffff88805e4080e0 (&type->s_umount_key#120){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88805e4080e0 (&type->s_umount_key#120){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117
1 lock held by syz.9.467/8626:
#0: ffff88805e4080e0 (&type->s_umount_key#120){.+.+}-{3:3}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88805e4080e0 (&type->s_umount_key#120){.+.+}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117
3 locks held by syz.6.516/8906:
#0: ffff888076dc8e20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
#0: ffff888076dc8e20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:658 [inline]
#0: ffff888076dc8e20 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x9b/0x230 net/socket.c:1421
#1: ffffffff8e0182b0 ((netlink_chain).rwsem){++++}-{3:3}, at: blocking_notifier_call_chain+0x54/0x90 kernel/notifier.c:387
#2: ffff88802c3d8ab8 (&nft_net->commit_mutex){+.+.}-{3:3}, at: nft_rcv_nl_event+0x115/0x590 net/netfilter/nf_tables_api.c:11383
2 locks held by syz.6.516/8907:
#0: ffff88802c3d8ab8 (&nft_net->commit_mutex){+.+.}-{3:3}, at: nf_tables_valid_genid+0x3b/0x100 net/netfilter/nf_tables_api.c:10783
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#1: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004
3 locks held by dhcpcd-run-hook/8916:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 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+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5121 Comm: syslogd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:980 [inline]
RIP: 0010:debug_check_no_obj_freed+0x1ce/0x540 lib/debugobjects.c:1020
Code: 00 00 48 ba 00 00 00 00 00 fc ff df ff c3 48 8b 04 24 48 89 c5 48 85 c0 0f 84 40 03 00 00 49 89 ee 49 c1 ee 03 41 80 3c 16 00 <74> 12 48 89 ef e8 68 ad b6 fd 48 ba 00 00 00 00 00 fc ff df 48 8b
RSP: 0018:ffffc90003267830 EFLAGS: 00000046
RAX: 1ffffffff2e2892a RBX: 0000000000000000 RCX: dffffc0000000000
RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffffc90003267720
RBP: ffff888044f65ce8 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200064cee4 R12: ffff88802c1d4a00
R13: ffff88802c1d4800 R14: 1ffff110089ecb9d R15: 0000000000000001
FS: 00007f9422d1fc80(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d49d344da0 CR3: 000000002fcc6000 CR4: 00000000003506e0
DR0: 0000000000000008 DR1: 0000000000000001 DR2: 0000000000000004
DR3: 0000000000000008 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
slab_free_hook mm/slub.c:1786 [inline]
slab_free_freelist_hook+0xd2/0x1b0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
__kmem_cache_free+0xba/0x1f0 mm/slub.c:3843
skb_kfree_head net/core/skbuff.c:949 [inline]
skb_free_head net/core/skbuff.c:961 [inline]
skb_release_data+0x634/0x800 net/core/skbuff.c:991
skb_release_all net/core/skbuff.c:1057 [inline]
__kfree_skb net/core/skbuff.c:1071 [inline]
consume_skb+0xb2/0x110 net/core/skbuff.c:1287
__unix_dgram_recvmsg+0xa04/0xd60 net/unix/af_unix.c:2490
sock_recvmsg_nosec net/socket.c:1046 [inline]
sock_recvmsg net/socket.c:1068 [inline]
sock_read_iter+0x2b7/0x3b0 net/socket.c:1138
call_read_iter include/linux/fs.h:2012 [inline]
new_sync_read fs/read_write.c:389 [inline]
vfs_read+0x431/0x920 fs/read_write.c:470
ksys_read+0x147/0x250 fs/read_write.c:613
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f9422e6f407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffefb830520 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f9422d1fc80 RCX: 00007f9422e6f407
RDX: 00000000000000ff RSI: 000055d132761950 RDI: 0000000000000000
RBP: 000055d132761910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055d13276198a
R13: 0000000000000000 R14: 000055d132761950 R15: 000055d113ed9d98