audit: type=1326 audit(8035336747.019:481): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=337 comm="syz-executor.4" exe="/root/syz-executor.4" sig=9 arch=c000003e syscall=228 compat=0 ip=0x45f89a code=0x0 audit: type=1326 audit(8035336749.271:482): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=363 comm="syz-executor.4" exe="/root/syz-executor.4" sig=9 arch=c000003e syscall=228 compat=0 ip=0x45f89a code=0x0 audit: type=1326 audit(8035336749.281:483): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=366 comm="syz-executor.0" exe="/root/syz-executor.0" sig=9 arch=c000003e syscall=228 compat=0 ip=0x45f89a code=0x0 netlink: 'syz-executor.1': attribute type 2 has an invalid length. INFO: task syz-executor.3:360 blocked for more than 140 seconds. Not tainted 4.19.129-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D29408 360 21515 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3515 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+0x647/0x1260 kernel/locking/mutex.c:1072 fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457 chrdev_open+0x266/0x770 fs/char_dev.c:423 do_dentry_open+0x4aa/0x1160 fs/open.c:796 do_last fs/namei.c:3421 [inline] path_openat+0x793/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_sys_open+0x3b3/0x520 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45ca59 Code: c7 04 24 ff ff ff ff 48 c7 44 24 08 ff ff ff ff 48 c7 44 24 10 00 00 00 00 48 8b 44 24 68 48 89 44 24 18 48 8b 44 24 70 48 89 <44> 24 20 48 8b 44 24 78 48 89 44 24 28 48 89 4c 24 30 0f 57 c0 0f RSP: 002b:00007f3993360c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f8060 RCX: 000000000045ca59 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007b7 R14: 00000000004ca95a R15: 00007f39933616d4 Showing all locks held in the system: 1 lock held by khungtaskd/1080: #0: 0000000090d7ec85 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440 1 lock held by in:imklog/6131: #0: 000000004bb25549 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 3 locks held by syz-executor.3/338: 1 lock held by syz-executor.3/360: #0: 00000000e125d4fd (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1080 Comm: khungtaskd Not tainted 4.19.129-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+0x1fc/0x2fe 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+0x991/0xe60 kernel/hung_task.c:287 kthread+0x30b/0x410 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 338 Comm: syz-executor.3 Not tainted 4.19.129-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_cmp4+0x4/0x20 kernel/kcov.c:162 Code: b6 f7 31 ff eb 80 48 8b 0c 24 0f b7 d6 0f b7 f7 bf 02 00 00 00 e9 6c ff ff ff 66 90 66 2e 0f 1f 84 00 00 00 00 00 48 8b 0c 24 <89> f2 89 fe bf 04 00 00 00 e9 4e ff ff ff 0f 1f 40 00 66 2e 0f 1f RSP: 0018:ffff8881f94ef2b8 EFLAGS: 00000282 RAX: 0000000000040000 RBX: 0000000000000050 RCX: ffffffff8385c574 RDX: 0000000000040000 RSI: 0000000000000019 RDI: 0000000000000050 RBP: 0000000000000019 R08: 0000000000000001 R09: 0000000000000050 R10: 0000000000000004 R11: 0000000000000000 R12: ffff8880000a0019 R13: ffff8880000a0000 R14: 0000000000000000 R15: 00000000ed080486 FS: 00007f39933a3700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c013692008 CR3: 000000008b277000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vga16fb_fillrect+0x9d4/0x1940 drivers/video/fbdev/vga16fb.c:922 bit_clear_margins+0x2d5/0x4a0 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins+0x1e2/0x350 drivers/video/fbdev/core/fbcon.c:1342 fbcon_switch+0x1038/0x1d26 drivers/video/fbdev/core/fbcon.c:2324 redraw_screen+0x37d/0x870 drivers/tty/vt/vt.c:1015 fbcon_modechanged+0x6e9/0x9f0 drivers/video/fbdev/core/fbcon.c:2972 fbcon_event_notify+0x197/0x1d80 drivers/video/fbdev/core/fbcon.c:3347 notifier_call_chain+0xc0/0x230 kernel/notifier.c:93 __blocking_notifier_call_chain kernel/notifier.c:317 [inline] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] blocking_notifier_call_chain kernel/notifier.c:328 [inline] blocking_notifier_call_chain+0x85/0xa0 kernel/notifier.c:325 fb_set_var+0xc51/0xe20 drivers/video/fbdev/core/fbmem.c:1042 do_fb_ioctl+0x3cf/0xb50 drivers/video/fbdev/core/fbmem.c:1115 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1230 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45ca59 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:00007f39933a2c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e5060 RCX: 000000000045ca59 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000004 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002f7 R14: 00000000004c575e R15: 00007f39933a36d4