INFO: task syz.6.2550:15745 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.2550 state:D stack:26464 pid:15745 ppid:6420 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6697
rwsem_down_read_slowpath+0x4f4/0x840 kernel/locking/rwsem.c:1094
__down_read_common kernel/locking/rwsem.c:1261 [inline]
__down_read kernel/locking/rwsem.c:1274 [inline]
down_read+0x94/0x2d0 kernel/locking/rwsem.c:1522
iterate_supers+0xa4/0x1d0 fs/super.c:755
ksys_sync+0x91/0x150 fs/sync.c:102
__ia32_sys_sync+0xa/0x10 fs/sync.c:113
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff4fc18f749
RSP: 002b:00007ff4fcfe1038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007ff4fc3e5fa0 RCX: 00007ff4fc18f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ff4fc3e5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff4fc3e6038 R14: 00007ff4fc3e5fa0 R15: 00007fff2d251228
INFO: task syz.6.2550:15752 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.2550 state:D stack:29024 pid:15752 ppid:6420 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6697
rwsem_down_read_slowpath+0x4f4/0x840 kernel/locking/rwsem.c:1094
__down_read_common kernel/locking/rwsem.c:1261 [inline]
__down_read kernel/locking/rwsem.c:1274 [inline]
down_read+0x94/0x2d0 kernel/locking/rwsem.c:1522
iterate_supers+0xa4/0x1d0 fs/super.c:755
ksys_sync+0x91/0x150 fs/sync.c:102
__ia32_sys_sync+0xa/0x10 fs/sync.c:113
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff4fc18f749
RSP: 002b:00007ff4fcfc0038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007ff4fc3e6090 RCX: 00007ff4fc18f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ff4fc3e6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff4fc3e6128 R14: 00007ff4fc3e6090 R15: 00007fff2d251228
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8c92bb70 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8c92c390 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
#0: ffffffff8c92b1e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8c92b1e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8c92b1e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
1 lock held by dhcpcd/3933:
#0: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x11f/0x6f0 net/netlink/af_netlink.c:2305
2 locks held by getty/4030:
#0: ffff88802fd4d098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
3 locks held by kworker/0:4/4275:
#0: ffff88802f0d1538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90003ee7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131
2 locks held by kworker/0:18/4464:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90004c37d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
5 locks held by kworker/u4:14/4571:
#0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90004f1fd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8db2f310 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594
#3: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe5/0xa50 net/core/dev.c:11489
#4: ffffffff8c930eb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#4: ffffffff8c930eb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962
3 locks held by kworker/1:13/4675:
#0: ffff88802f0d1538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900052cfd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131
3 locks held by kworker/0:20/5589:
#0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90003997d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:104
3 locks held by kworker/u4:11/10535:
#0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90005c9fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263
1 lock held by syz-executor/14390:
#0: ffff8880757120e0 (&type->s_umount_key#101){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
1 lock held by syz.6.2550/15745:
#0: ffff8880757120e0 (&type->s_umount_key#101){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755
1 lock held by syz.6.2550/15752:
#0: ffff8880757120e0 (&type->s_umount_key#101){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755
3 locks held by kworker/u4:22/16272:
1 lock held by syz-executor/16512:
#0: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz-executor/16549:
#0: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz-executor/17051:
#0: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz-executor/17075:
#0: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz.4.2793/17109:
#0: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz.4.2793/17110:
#0: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x11f/0x6f0 net/netlink/af_netlink.c:2305
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 28 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+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3620 Comm: syslogd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:kasan_get_free_meta mm/kasan/generic.c:444 [inline]
RIP: 0010:kasan_save_free_info+0xe/0x50 mm/kasan/generic.c:512
Code: c8 74 01 c3 48 89 f7 89 d6 e9 6e dc ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 63 bf c0 00 00 00 48 81 ff ff ff ff 7f <0f> 94 c0 48 01 f7 0f 94 c1 08 c1 75 25 53 48 89 f3 48 83 c7 08 be
RSP: 0018:ffffc900032a78a8 EFLAGS: 00000293
RAX: ffffed1005046300 RBX: ffff888028231800 RCX: 0000000000000000
RDX: 0000000000000040 RSI: ffff888028231800 RDI: 0000000000000000
RBP: 0000000000000001 R08: dffffc0000000000 R09: ffffed1005046300
R10: fffffbfff211965e R11: 1ffffffff211965d R12: 0000000000000000
R13: ffffc900032a7940 R14: ffff888017442dc0 R15: ffffffff81d070f6
FS: 00007fa0d603dc80(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f94b2db7198 CR3: 000000007e693000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237
kasan_slab_free include/linux/kasan.h:177 [inline]
slab_free_hook mm/slub.c:1729 [inline]
slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1755
slab_free mm/slub.c:3687 [inline]
__kmem_cache_free+0xb6/0x1f0 mm/slub.c:3700
skb_free_head net/core/skbuff.c:762 [inline]
skb_release_data+0x5db/0x7c0 net/core/skbuff.c:791
skb_release_all net/core/skbuff.c:856 [inline]
__kfree_skb net/core/skbuff.c:870 [inline]
consume_skb+0xa2/0x100 net/core/skbuff.c:1035
__unix_dgram_recvmsg+0xa06/0xd70 net/unix/af_unix.c:2531
sock_recvmsg_nosec net/socket.c:1022 [inline]
sock_recvmsg net/socket.c:1040 [inline]
sock_read_iter+0x2bf/0x370 net/socket.c:1121
call_read_iter include/linux/fs.h:2259 [inline]
new_sync_read fs/read_write.c:389 [inline]
vfs_read+0x434/0x920 fs/read_write.c:470
ksys_read+0x143/0x240 fs/read_write.c:613
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa0d618d407
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:00007fff855c9810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fa0d603dc80 RCX: 00007fa0d618d407
RDX: 00000000000000ff RSI: 000055a521699950 RDI: 0000000000000000
RBP: 000055a521699910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055a521699999
R13: 0000000000000000 R14: 000055a521699950 R15: 000055a50c422d98