INFO: task syz-executor.1:11904 blocked for more than 143 seconds. Not tainted 5.7.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D29536 11904 7342 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] do_fb_ioctl+0x426/0x6e0 drivers/video/fbdev/core/fbmem.c:1117 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:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c829 Code: 08 0f 57 c0 0f 11 44 24 48 48 8b 4c 24 30 48 89 4c 24 48 48 89 44 24 50 48 8b 4c 24 48 48 8b 54 24 78 48 39 c2 74 12 c6 84 24 <90> 00 00 00 00 48 8b 6c 24 58 48 83 c4 60 c3 48 8b 44 24 70 48 89 RSP: 002b:00007f6b77ce1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e4580 RCX: 000000000045c829 RDX: 0000000020000000 RSI: 0000000000004602 RDI: 0000000000000004 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002eb R14: 00000000004c5423 R15: 00007f6b77ce26d4 INFO: task syz-executor.1:11939 blocked for more than 143 seconds. Not tainted 5.7.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28400 11939 7342 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/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+0x4ba/0x1290 fs/open.c:797 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:1148 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c829 Code: 08 0f 57 c0 0f 11 44 24 48 48 8b 4c 24 30 48 89 4c 24 48 48 89 44 24 50 48 8b 4c 24 48 48 8b 54 24 78 48 39 c2 74 12 c6 84 24 <90> 00 00 00 00 48 8b 6c 24 58 48 83 c4 60 c3 48 8b 44 24 70 48 89 RSP: 002b:00007f6b77c9fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f7140 RCX: 000000000045c829 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078c0e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000079a R14: 00000000004ca4cf R15: 00007f6b77ca06d4 Showing all locks held in the system: 1 lock held by khungtaskd/1136: #0: ffffffff899bed80 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5754 1 lock held by in:imklog/6894: #0: ffff8880999ab130 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 2 locks held by syz-executor.1/11901: 1 lock held by syz-executor.1/11904: #0: ffff8880a3a92078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a3a92078 (&fb_info->lock){+.+.}-{3:3}, at: do_fb_ioctl+0x426/0x6e0 drivers/video/fbdev/core/fbmem.c:1117 1 lock held by syz-executor.1/11939: #0: ffff8880a3a92078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a3a92078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1136 Comm: khungtaskd Not tainted 5.7.0-rc2-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+0x231/0x27e 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:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 11901 Comm: syz-executor.1 Not tainted 5.7.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:bitfill_aligned drivers/video/fbdev/core/cfbfillrect.c:63 [inline] RIP: 0010:bitfill_aligned+0x145/0x200 drivers/video/fbdev/core/cfbfillrect.c:35 Code: 30 48 83 c5 40 48 89 18 41 83 ef 08 bf 07 00 00 00 44 89 fe e8 2c be b3 fd 41 83 ff 07 77 bd 41 8d 44 24 f8 44 89 e5 c1 e8 03 <83> e5 07 48 83 c0 01 48 c1 e0 06 49 01 c5 e8 98 bc b3 fd 44 8d 7d RSP: 0018:ffffc90017546fb0 EFLAGS: 00000202 RAX: 0000000000000004 RBX: 0000000000000000 RCX: ffffffff83bf71f4 RDX: 0000000000000000 RSI: 0000000000000007 RDI: 0000000000000005 RBP: 0000000000000028 R08: ffff88808df70000 R09: 0000000000000040 R10: ffff8880a3a95d1f R11: ffffed1014752ba3 R12: 0000000000000028 R13: ffff8880000a0000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f6b77d03700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff3526ce89 CR3: 000000009b631000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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+0xd21/0x1740 drivers/video/fbdev/core/fbcon.c:2363 redraw_screen+0x2ae/0x770 drivers/tty/vt/vt.c:1009 fbcon_modechanged+0x5c3/0x790 drivers/video/fbdev/core/fbcon.c:3000 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3047 fb_set_var+0xad0/0xd40 drivers/video/fbdev/core/fbmem.c:1056 fbcon_switch+0x526/0x1740 drivers/video/fbdev/core/fbcon.c:2296 redraw_screen+0x2ae/0x770 drivers/tty/vt/vt.c:1009 fbcon_modechanged+0x5c3/0x790 drivers/video/fbdev/core/fbcon.c:3000 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3047 fb_set_var+0xad0/0xd40 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:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 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:00007f6b77d02c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e46c0 RCX: 000000000045c829 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000004 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002f0 R14: 00000000004c5497 R15: 00007f6b77d036d4