INFO: task syz.4.2898:14353 blocked for more than 143 seconds.
Not tainted 6.14.0-rc1-syzkaller-00034-g92514ef226f5 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2898 state:D stack:27488 pid:14353 tgid:14349 ppid:8425 task_flags:0x400040 flags:0x00000004
Call Trace:
context_switch kernel/sched/core.c:5377 [inline]
__schedule+0xf43/0x5890 kernel/sched/core.c:6764
__schedule_loop kernel/sched/core.c:6841 [inline]
schedule+0xe7/0x350 kernel/sched/core.c:6856
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6913
__mutex_lock_common kernel/locking/mutex.c:662 [inline]
__mutex_lock+0x6bd/0xb10 kernel/locking/mutex.c:730
nfsd_nl_threads_get_doit+0x1c7/0x740 fs/nfsd/nfsctl.c:1713
genl_family_rcv_msg_doit+0x202/0x2f0 net/netlink/genetlink.c:1115
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0x565/0x800 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2543
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1348
netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1892
sock_sendmsg_nosec net/socket.c:713 [inline]
__sock_sendmsg net/socket.c:728 [inline]
____sys_sendmsg+0x9ae/0xb40 net/socket.c:2568
___sys_sendmsg+0x135/0x1e0 net/socket.c:2622
__sys_sendmsg+0x16e/0x220 net/socket.c:2654
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa6d938cde9
RSP: 002b:00007fa6da16a038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fa6d95a6080 RCX: 00007fa6d938cde9
RDX: 0000000004040000 RSI: 00002000000001c0 RDI: 0000000000000003
RBP: 00007fa6d940e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007fa6d95a6080 R15: 00007fffdcf0f228
Showing all locks held in the system:
2 locks held by kworker/u8:1/12:
1 lock held by khungtaskd/30:
#0: ffffffff8e1bc140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#0: ffffffff8e1bc140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8e1bc140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746
4 locks held by kworker/u8:8/3025:
#0: ffff88801bef5948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12cd/0x1b30 kernel/workqueue.c:3211
#1: ffffc9000c1d7d18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1b30 kernel/workqueue.c:3212
#2: ffffffff8fec1ed0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xca/0xbf0 net/core/net_namespace.c:606
#3: ffffffff8e1c75b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x282/0x3b0 kernel/rcu/tree_exp.h:302
2 locks held by getty/14098:
#0: ffff88814dc290a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc90002ee22f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211
2 locks held by syz.4.2898/14350:
#0: ffffffff8ff783b0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e5bd9c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xe3/0x1b40 fs/nfsd/nfsctl.c:1922
2 locks held by syz.4.2898/14353:
#0: ffffffff8ff783b0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e5bd9c8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1c7/0x740 fs/nfsd/nfsctl.c:1713
1 lock held by syz.3.3504/16554:
3 locks held by syz.5.3523/16598:
2 locks held by syz.5.3527/16614:
1 lock held by syz.1.3532/16624:
1 lock held by syz.6.3531/16627:
1 lock held by syz.1.3532/16629:
#0: ffffffff8e1c75b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:334
3 locks held by syz.6.3548/16690:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc1-syzkaller-00034-g92514ef226f5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/0x300 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+0xf62/0x12b0 kernel/hung_task.c:399
kthread+0x3af/0x750 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16614 Comm: syz.5.3527 Not tainted 6.14.0-rc1-syzkaller-00034-g92514ef226f5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:write_comp_data+0x8b/0x90 kernel/kcov.c:272
Code: 00 00 4a 8d 34 dd 28 00 00 00 48 39 f2 72 1b 48 83 c7 01 48 89 38 4c 89 44 30 e0 4c 89 4c 30 e8 4c 89 54 30 f0 4a 89 4c d8 20 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3
RSP: 0018:ffffc90004fb6e88 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffffea0000f32a00 RCX: ffffffff81f8d776
RDX: ffff888027f00000 RSI: 0000000000000000 RDI: 0000000000000007
RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000002 R12: ffff8880125b3e68
R13: 0000000000006f7b R14: 0000000000000cc0 R15: dffffc0000000000
FS: 00007f02a70176c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000004021000 CR3: 000000005c848000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
const_folio_flags.constprop.0+0x36/0x70 include/linux/page-flags.h:310
folio_test_head include/linux/page-flags.h:829 [inline]
folio_test_large include/linux/page-flags.h:850 [inline]
folio_order include/linux/mm.h:1128 [inline]
shmem_add_to_page_cache+0x96/0x9b0 mm/shmem.c:873
shmem_alloc_and_add_folio+0x662/0xc10 mm/shmem.c:1928
shmem_get_folio_gfp+0x689/0x1530 mm/shmem.c:2522
shmem_get_folio mm/shmem.c:2628 [inline]
shmem_write_begin+0x161/0x300 mm/shmem.c:3278
generic_perform_write+0x2ba/0x920 mm/filemap.c:4189
shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3454
__kernel_write_iter+0x318/0xa90 fs/read_write.c:612
dump_emit_page fs/coredump.c:884 [inline]
dump_user_range+0x389/0x8c0 fs/coredump.c:945
elf_core_dump+0x2787/0x3880 fs/binfmt_elf.c:2129
do_coredump+0x304f/0x45d0 fs/coredump.c:758
get_signal+0x23f3/0x2610 kernel/signal.c:3021
arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x200000
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 002b:000000000000000a EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f02a63a5fa0 RCX: 00007f02a618cde9
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000020003b46
RBP: 00007f02a620e2a0 R08: 0000000000000002 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f02a63a5fa0 R15: 00007ffd2699f618