INFO: task syz.1.1243:12159 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1243 state:D stack:28248 pid:12159 tgid:12155 ppid:5828 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0xfee/0x60e0 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
expkey_flush+0x18/0x90 fs/nfsd/export.c:250
write_flush.isra.0+0x2af/0x3d0 net/sunrpc/cache.c:1551
pde_write fs/proc/inode.c:330 [inline]
proc_reg_write+0x240/0x330 fs/proc/inode.c:342
do_loop_readv_writev fs/read_write.c:852 [inline]
do_loop_readv_writev fs/read_write.c:837 [inline]
vfs_writev+0x5ea/0xe10 fs/read_write.c:1061
do_writev+0x13e/0x340 fs/read_write.c:1105
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f49e779c629
RSP: 002b:00007f49e8675028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f49e7a16270 RCX: 00007f49e779c629
RDX: 000000000000000a RSI: 0000200000000240 RDI: 0000000000000005
RBP: 00007f49e7832b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f49e7a16308 R14: 00007f49e7a16270 R15: 00007ffed4d7e1a8
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7e9220 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by syz.3.872/10238:
#0: ffffffff906be0b0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec58388 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1b20 fs/nfsd/nfsctl.c:1893
3 locks held by kworker/u10:3/10289:
2 locks held by syz-executor/10434:
#0: ffff88802cb920e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88802cb920e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88802cb920e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: deactivate_super fs/super.c:508 [inline]
#0: ffff88802cb920e0 (&type->s_umount_key#55){+.+.}-{4:4}, at: deactivate_super+0xdf/0x110 fs/super.c:505
#1: ffffffff8ec58388 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_shutdown_threads+0x5b/0xf0 fs/nfsd/nfssvc.c:575
2 locks held by kworker/u10:7/10585:
3 locks held by syz.1.1243/12159:
#0: ffff88805a3c0b78 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x2aa/0x380 fs/file.c:1261
#1: ffff8880294c8420 (sb_writers#3){.+.+}-{0:0}, at: do_writev+0x13e/0x340 fs/read_write.c:1105
#2: ffffffff8ec58388 (nfsd_mutex){+.+.}-{4:4}, at: expkey_flush+0x18/0x90 fs/nfsd/export.c:250
2 locks held by getty/13273:
#0: ffff88803725b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc90003d4d2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
4 locks held by kworker/u10:27/13496:
#0: ffff88801c6ae948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250
#1: ffffc900038f7d08 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251
#2: ffffffff905f95d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xb8/0x920 net/core/net_namespace.c:675
#3: ffffffff8e7f4e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
2 locks held by syz.2.1607/13881:
#0: ffff88807f82c420 (sb_writers#5){.+.+}-{0:0}, at: get_signal+0x1f2a/0x21e0 kernel/signal.c:3019
#1: ffff88803512c080 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_killable include/linux/mmap_lock.h:601 [inline]
#1: ffff88803512c080 (&mm->mmap_lock){++++}-{4:4}, at: dump_user_range+0x151/0xb50 fs/coredump.c:1355
2 locks held by syz.5.1614/13904:
1 lock held by syz.2.1613/13909:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xd25/0x1050 kernel/hung_task.c:515
kthread+0x370/0x450 kernel/kthread.c:467
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5809 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:aa_file_perm+0xff/0x14d0 security/apparmor/file.c:632
Code: 80 3c 02 00 0f 85 32 12 00 00 48 c7 c0 e8 ac 34 9b 48 8b ab 88 00 00 00 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 <0f> 85 fb 11 00 00 48 3b 2d cc b2 83 16 0f 84 2f 0d 00 00 e8 19 01
RSP: 0018:ffffc90003c07b20 EFLAGS: 00000246
RAX: 1ffffffff366959d RBX: ffff888076b4ee00 RCX: 1ffff92000780f6f
RDX: dffffc0000000000 RSI: ffffffff84b0f9cd RDI: ffffffff8c129d40
RBP: ffff88807ce00758 R08: 0000000000000004 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88801c6e1cf8
R13: ffff888076b4ee88 R14: ffff8880352088d0 R15: 00007ffee7df8cec
FS: 000055557ecf8500(0000) GS:ffff888124351000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f77db385f88 CR3: 0000000076b5a000 CR4: 00000000003526f0
Call Trace:
common_file_perm security/apparmor/lsm.c:529 [inline]
apparmor_file_permission+0x6d/0x1c0 security/apparmor/lsm.c:542
security_file_permission+0x91/0x210 security/security.c:2366
rw_verify_area+0xb8/0x6d0 fs/read_write.c:475
vfs_read+0x150/0xb30 fs/read_write.c:565
ksys_read+0x1f8/0x250 fs/read_write.c:717
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7059357817
Code: 48 89 fa 4c 89 df e8 a8 56 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:00007ffee7df8c90 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 000055557ecf8500 RCX: 00007f7059357817
RDX: 0000000000000004 RSI: 00007ffee7df8cec RDI: 0000000000000003
RBP: 00007ffee7df9190 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004
R13: 00007ffee7df8cec R14: 00007ffee7df8d80 R15: 0000000000000000