INFO: task syz-executor.3:31708 blocked for more than 143 seconds. Not tainted 5.7.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D29616 31708 7025 0x00000004 Call Trace: context_switch kernel/sched/core.c:3430 [inline] __schedule+0x8f3/0x1fc0 kernel/sched/core.c:4156 schedule+0xd0/0x2a0 kernel/sched/core.c:4231 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4290 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7b3/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] do_fb_ioctl+0x1b5/0x6e0 drivers/video/fbdev/core/fbmem.c:1168 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:771 __do_sys_ioctl fs/ioctl.c:780 [inline] __se_sys_ioctl fs/ioctl.c:778 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:778 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca59 Code: 48 8d 3d 02 7c 28 01 e8 c5 22 00 00 e9 18 ff ff ff 48 8d 3d e9 7b 28 01 e8 b4 22 00 00 e9 ec fe ff ff e8 aa 04 00 00 e9 85 fe ff cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00007f791a478c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e5e20 RCX: 000000000045ca59 RDX: 0000000020000040 RSI: 0000000040305828 RDI: 0000000000000009 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000032e R14: 00000000004c5b5a R15: 00007f791a4796d4 INFO: task syz-executor.3:31709 blocked for more than 143 seconds. Not tainted 5.7.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D27480 31709 7025 0x00000004 Call Trace: context_switch kernel/sched/core.c:3430 [inline] __schedule+0x8f3/0x1fc0 kernel/sched/core.c:4156 schedule+0xd0/0x2a0 kernel/sched/core.c:4231 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4290 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7b3/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x546/0x1340 fs/open.c:828 do_open fs/namei.c:3229 [inline] path_openat+0x1e59/0x27d0 fs/namei.c:3346 do_filp_open+0x192/0x260 fs/namei.c:3373 do_sys_openat2+0x585/0x7d0 fs/open.c:1179 do_sys_open+0xc3/0x140 fs/open.c:1195 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca59 Code: 48 8d 3d 02 7c 28 01 e8 c5 22 00 00 e9 18 ff ff ff 48 8d 3d e9 7b 28 01 e8 b4 22 00 00 e9 ec fe ff ff e8 aa 04 00 00 e9 85 fe ff cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00007f791a457c78 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: 00007f791a4586d4 Showing all locks held in the system: 1 lock held by khungtaskd/1147: #0: ffffffff899bdd80 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5779 1 lock held by in:imklog/6475: #0: ffff88809f63cdf0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 2 locks held by syz-executor.3/31705: 1 lock held by syz-executor.3/31708: #0: ffff8880a3ec3078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a3ec3078 (&fb_info->lock){+.+.}-{3:3}, at: do_fb_ioctl+0x1b5/0x6e0 drivers/video/fbdev/core/fbmem.c:1168 1 lock held by syz-executor.3/31709: #0: ffff8880a3ec3078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a3ec3078 (&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: 1147 Comm: khungtaskd Not tainted 5.7.0-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+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1e6/0x221 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa8c/0x1010 kernel/hung_task.c:289 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 31705 Comm: syz-executor.3 Not tainted 5.7.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:252 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:165 [inline] RIP: 0010:write_comp_data+0x27/0x80 kernel/kcov.c:218 Code: 00 00 00 65 4c 8b 04 25 00 1f 02 00 65 8b 05 98 4f 8e 7e a9 00 01 ff 00 74 10 f6 c4 01 74 5c 41 8b 80 04 14 00 00 85 c0 74 51 <41> 8b 80 e0 13 00 00 83 f8 03 75 45 49 8b 80 e8 13 00 00 45 8b 80 RSP: 0018:ffffc90004cb74d8 EFLAGS: 00000246 RAX: 0000000080000000 RBX: 0000000000000000 RCX: ffffffff83c32425 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000040 R08: ffff888057f5a000 R09: 0000000000000040 R10: ffff8880a3e0bf1f R11: ffffed10147c17e3 R12: 00000000000000c0 R13: ffff8880000a0000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f791a49a700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c00dd58758 CR3: 000000009f489000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bitfill_aligned drivers/video/fbdev/core/cfbfillrect.c:55 [inline] bitfill_aligned+0xc5/0x200 drivers/video/fbdev/core/cfbfillrect.c:35 cfb_fillrect+0x418/0x7a0 drivers/video/fbdev/core/cfbfillrect.c:327 vga16fb_fillrect+0x68f/0x1960 drivers/video/fbdev/vga16fb.c:951 bit_clear_margins+0x2d5/0x4a0 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins+0x1de/0x240 drivers/video/fbdev/core/fbcon.c:1381 fbcon_switch+0xcde/0x16f0 drivers/video/fbdev/core/fbcon.c:2363 redraw_screen+0x2ae/0x770 drivers/tty/vt/vt.c:1015 fbcon_modechanged+0x581/0x720 drivers/video/fbdev/core/fbcon.c:3000 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3047 fb_set_var+0xb03/0xd90 drivers/video/fbdev/core/fbmem.c:1056 do_fb_ioctl+0x390/0x6e0 drivers/video/fbdev/core/fbmem.c:1109 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:771 __do_sys_ioctl fs/ioctl.c:780 [inline] __se_sys_ioctl fs/ioctl.c:778 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:778 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 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:00007f791a499c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e5060 RCX: 000000000045ca59 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000009 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002f7 R14: 00000000004c575e R15: 00007f791a49a6d4