INFO: task syz-executor.5:28384 can't die for more than 143 seconds. syz-executor.5 D28616 28384 7352 0x00004004 Call Trace: context_switch kernel/sched/core.c:3533 [inline] __schedule+0x908/0x21e0 kernel/sched/core.c:4289 schedule+0xd0/0x2a0 kernel/sched/core.c:4364 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4423 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:638 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4b9/0x11b0 fs/open.c:827 do_open fs/namei.c:3249 [inline] path_openat+0x1b97/0x2720 fs/namei.c:3366 do_filp_open+0x17e/0x3c0 fs/namei.c:3393 do_sys_openat2+0x16d/0x3e0 fs/open.c:1178 do_sys_open fs/open.c:1194 [inline] __do_sys_openat fs/open.c:1210 [inline] __se_sys_openat fs/open.c:1205 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1205 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c1f9 Code: Bad RIP value. RSP: 002b:00007fb83ffd1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000020f00 RCX: 000000000045c1f9 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078bfe8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bfac R13: 00007fff6dc2982f R14: 00007fb83ffd29c0 R15: 000000000078bfac INFO: task syz-executor.5:28384 blocked for more than 143 seconds. Not tainted 5.8.0-rc6-next-20200722-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28616 28384 7352 0x00004004 Call Trace: context_switch kernel/sched/core.c:3533 [inline] __schedule+0x908/0x21e0 kernel/sched/core.c:4289 schedule+0xd0/0x2a0 kernel/sched/core.c:4364 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4423 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:638 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4b9/0x11b0 fs/open.c:827 do_open fs/namei.c:3249 [inline] path_openat+0x1b97/0x2720 fs/namei.c:3366 do_filp_open+0x17e/0x3c0 fs/namei.c:3393 do_sys_openat2+0x16d/0x3e0 fs/open.c:1178 do_sys_open fs/open.c:1194 [inline] __do_sys_openat fs/open.c:1210 [inline] __se_sys_openat fs/open.c:1205 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1205 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c1f9 Code: Bad RIP value. RSP: 002b:00007fb83ffd1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000020f00 RCX: 000000000045c1f9 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078bfe8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bfac R13: 00007fff6dc2982f R14: 00007fb83ffd29c0 R15: 000000000078bfac INFO: task syz-executor.5:28387 can't die for more than 143 seconds. syz-executor.5 D28432 28387 7352 0x00000004 Call Trace: context_switch kernel/sched/core.c:3533 [inline] __schedule+0x908/0x21e0 kernel/sched/core.c:4289 schedule+0xd0/0x2a0 kernel/sched/core.c:4364 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4423 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:638 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4b9/0x11b0 fs/open.c:827 do_open fs/namei.c:3249 [inline] path_openat+0x1b97/0x2720 fs/namei.c:3366 do_filp_open+0x17e/0x3c0 fs/namei.c:3393 do_sys_openat2+0x16d/0x3e0 fs/open.c:1178 do_sys_open fs/open.c:1194 [inline] __do_sys_openat fs/open.c:1210 [inline] __se_sys_openat fs/open.c:1205 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1205 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c1f9 Code: Bad RIP value. RSP: 002b:00007fb83ffb0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000020f00 RCX: 000000000045c1f9 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078c088 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078c04c R13: 00007fff6dc2982f R14: 00007fb83ffb19c0 R15: 000000000078c04c INFO: task syz-executor.5:28387 blocked for more than 143 seconds. Not tainted 5.8.0-rc6-next-20200722-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28432 28387 7352 0x00000004 Call Trace: context_switch kernel/sched/core.c:3533 [inline] __schedule+0x908/0x21e0 kernel/sched/core.c:4289 schedule+0xd0/0x2a0 kernel/sched/core.c:4364 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4423 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:638 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x266/0x770 fs/char_dev.c:414 do_dentry_open+0x4b9/0x11b0 fs/open.c:827 do_open fs/namei.c:3249 [inline] path_openat+0x1b97/0x2720 fs/namei.c:3366 do_filp_open+0x17e/0x3c0 fs/namei.c:3393 do_sys_openat2+0x16d/0x3e0 fs/open.c:1178 do_sys_open fs/open.c:1194 [inline] __do_sys_openat fs/open.c:1210 [inline] __se_sys_openat fs/open.c:1205 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1205 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c1f9 Code: Bad RIP value. RSP: 002b:00007fb83ffb0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000020f00 RCX: 000000000045c1f9 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078c088 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078c04c R13: 00007fff6dc2982f R14: 00007fb83ffb19c0 R15: 000000000078c04c Showing all locks held in the system: 1 lock held by khungtaskd/1150: #0: ffffffff89c52bc0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5817 1 lock held by in:imklog/6664: #0: ffff888094816af0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 2 locks held by syz-executor.3/28148: 1 lock held by syz-executor.5/28384: #0: ffff8882188d0078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:638 [inline] #0: ffff8882188d0078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by syz-executor.5/28387: #0: ffff8882188d0078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:638 [inline] #0: ffff8882188d0078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1150 Comm: khungtaskd Not tainted 5.8.0-rc6-next-20200722-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+0x18f/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] watchdog+0xd89/0xf30 kernel/hung_task.c:339 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 28148 Comm: syz-executor.3 Not tainted 5.8.0-rc6-next-20200722-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:258 Code: 84 00 00 00 00 00 48 8b 0c 24 0f b7 d6 0f b7 f7 bf 02 00 00 00 e9 4c 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 2e ff ff ff 0f 1f 40 00 66 2e 0f 1f RSP: 0018:ffffc90015e1f5c8 EFLAGS: 00000282 RAX: 0000000000000000 RBX: 0000000000000050 RCX: ffffffff83c8ae34 RDX: ffff8880947100c0 RSI: 000000000000001c RDI: 0000000000000050 RBP: 000000000000001c R08: 0000000000000001 R09: ffff8882188c05df R10: 0000000000000050 R11: 0000000000000000 R12: ffff8880000a001c R13: ffff8880000a0000 R14: 0000000000000000 R15: 00000000ef16805c FS: 00007f1f3f698700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000561eca7f9e48 CR3: 0000000097aef000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vga16fb_fillrect+0x9d4/0x193b drivers/video/fbdev/vga16fb.c:922 bit_clear_margins+0x2d5/0x4a0 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins+0x1d5/0x230 drivers/video/fbdev/core/fbcon.c:1381 fbcon_switch+0xb6f/0x16c0 drivers/video/fbdev/core/fbcon.c:2363 redraw_screen+0x2af/0x770 drivers/tty/vt/vt.c:1020 fbcon_modechanged+0x575/0x710 drivers/video/fbdev/core/fbcon.c:3001 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3048 fb_set_var+0xae8/0xd60 drivers/video/fbdev/core/fbmem.c:1056 do_fb_ioctl+0x33f/0x6c0 drivers/video/fbdev/core/fbmem.c:1109 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c1f9 Code: Bad RIP value. RSP: 002b:00007f1f3f697c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 000000000000d440 RCX: 000000000045c1f9 RDX: 0000000020000200 RSI: 0000000000004601 RDI: 0000000000000003 RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007ffccee0d4af R14: 00007f1f3f6989c0 R15: 000000000078bf0c