netlink: 24 bytes leftover after parsing attributes in process `syz-executor.2'. INFO: task syz-executor.3:24057 blocked for more than 140 seconds. Not tainted 4.19.121-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28416 24057 6753 0x00000004 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072 fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457 chrdev_open+0x219/0x5c0 fs/char_dev.c:423 do_dentry_open+0x4a8/0x1160 fs/open.c:796 do_last fs/namei.c:3421 [inline] path_openat+0x1031/0x4200 fs/namei.c:3537 do_filp_open+0x1a1/0x280 fs/namei.c:3567 do_sys_open+0x3c0/0x500 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c829 Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fa917cb1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f73e0 RCX: 000000000045c829 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007a0 R14: 00000000004ca544 R15: 00007fa917cb26d4 Showing all locks held in the system: 1 lock held by khungtaskd/1079: #0: 00000000e321d093 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440 1 lock held by in:imklog/6145: #0: 0000000005e7cc80 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:767 8 locks held by kworker/u4:4/3805: 3 locks held by syz-executor.3/24053: 1 lock held by syz-executor.3/24057: #0: 00000000ca2be1fb (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1079 Comm: khungtaskd Not tainted 4.19.121-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x962/0xe40 kernel/hung_task.c:287 kthread+0x34a/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3805 Comm: kworker/u4:4 Not tainted 4.19.121-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: krdsd rds_connect_worker RIP: 0010:atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] RIP: 0010:rcu_dynticks_curr_cpu_in_eqs+0x47/0xa0 kernel/rcu/tree.c:350 Code: c0 48 8d 3c c5 00 3f 9e 88 48 89 f9 48 c1 e9 03 80 3c 11 00 75 5b 48 03 1c c5 00 3f 9e 88 be 04 00 00 00 48 8d 6b 10 48 89 ef 84 fe 46 00 48 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 RSP: 0018:ffff888046277628 EFLAGS: 00000282 RAX: 0000000000000001 RBX: ffff8880ae723980 RCX: 1ffffffff113c7e1 RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffff8880ae723990 RBP: ffff8880ae723990 R08: ffff88804c8e0300 R09: ffffed1015ce4733 R10: ffffed1015ce4732 R11: ffff8880ae723993 R12: ffff888055c08140 R13: 0000000000000001 R14: ffff88804eb94101 R15: ffff8880875bd098 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055c357d896e8 CR3: 0000000095ef8000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_is_watching+0xc/0x20 kernel/rcu/tree.c:1025 rcu_read_lock_held+0x7c/0xc0 kernel/rcu/update.c:283 skb_dst include/linux/skbuff.h:895 [inline] __ip_local_out+0x630/0x810 net/ipv4/ip_output.c:114 ip_local_out+0x26/0x170 net/ipv4/ip_output.c:122 __ip_queue_xmit+0x85a/0x1bc0 net/ipv4/ip_output.c:505 __tcp_transmit_skb+0x19d5/0x3750 net/ipv4/tcp_output.c:1146 __tcp_send_ack.part.0+0x3e9/0x5d0 net/ipv4/tcp_output.c:3635 __tcp_send_ack net/ipv4/tcp_output.c:3641 [inline] tcp_send_ack+0x7d/0xa0 net/ipv4/tcp_output.c:3641 tcp_rcv_synsent_state_process net/ipv4/tcp_input.c:5902 [inline] tcp_rcv_state_process+0x37fd/0x4ec5 net/ipv4/tcp_input.c:6039 tcp_v4_do_rcv+0x34c/0x8b0 net/ipv4/tcp_ipv4.c:1557 sk_backlog_rcv include/net/sock.h:946 [inline] __release_sock+0x134/0x3a0 net/core/sock.c:2342 release_sock+0x54/0x1c0 net/core/sock.c:2858 inet_stream_connect+0x76/0xa0 net/ipv4/af_inet.c:720 rds_tcp_conn_path_connect+0x620/0x880 net/rds/tcp_connect.c:172 rds_connect_worker+0x194/0x2b0 net/rds/threads.c:175 process_one_work+0x91f/0x1640 kernel/workqueue.c:2155 worker_thread+0x96/0xe20 kernel/workqueue.c:2298 kthread+0x34a/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415