INFO: task syz-executor.3:11058 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 D28400 11058 7116 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_timeout+0x55b/0x850 kernel/time/timer.c:1873 __down_common kernel/locking/semaphore.c:220 [inline] __down+0x176/0x2c0 kernel/locking/semaphore.c:237 down+0x57/0x80 kernel/locking/semaphore.c:61 console_lock+0x25/0x80 kernel/printk/printk.c:2331 do_fb_ioctl+0x335/0x6e0 drivers/video/fbdev/core/fbmem.c:1106 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 e2 b7 28 01 e8 c5 22 00 00 e9 18 ff ff ff 48 8d 3d c9 b7 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:00007f2c2a77ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e5240 RCX: 000000000045ca59 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000005 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002fb R14: 00000000004c5797 R15: 00007f2c2a77f6d4 INFO: task syz-executor.0:11050 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.0 D28400 11050 6812 0x80004002 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_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1447 __fput+0x33e/0x880 fs/file_table.c:281 task_work_run+0xf4/0x1b0 kernel/task_work.c:123 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xb3f/0x2de0 kernel/exit.c:806 do_group_exit+0x125/0x340 kernel/exit.c:904 get_signal+0x47b/0x2510 kernel/signal.c:2739 do_signal+0x81/0x2240 arch/x86/kernel/signal.c:810 exit_to_usermode_loop+0x26c/0x360 arch/x86/entry/common.c:161 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca59 Code: 48 8d 3d e2 b7 28 01 e8 c5 22 00 00 e9 18 ff ff ff 48 8d 3d c9 b7 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:00007f6ea5613c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: 0000000000000008 RBX: 00000000004f8340 RCX: 000000000045ca59 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007bf R14: 00000000004ca9ed R15: 00007f6ea56146d4 INFO: task syz-executor.4:11062 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.4 D22792 11062 7365 0x00004004 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 e2 b7 28 01 e8 c5 22 00 00 e9 18 ff ff ff 48 8d 3d c9 b7 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:00007fc4b4981c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f8340 RCX: 000000000045ca59 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007bf R14: 00000000004ca9ed R15: 00007fc4b49826d4 INFO: task syz-executor.2:11072 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.2 D26232 11072 7023 0x00004004 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 e2 b7 28 01 e8 c5 22 00 00 e9 18 ff ff ff 48 8d 3d c9 b7 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:00007f9992b1cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f8340 RCX: 000000000045ca59 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007bf R14: 00000000004ca9ed R15: 00007f9992b1d6d4 Showing all locks held in the system: 1 lock held by khungtaskd/1148: #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/6474: #0: ffff8880973ab3f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 2 locks held by syz-executor.1/11046: 1 lock held by syz-executor.0/11050: #0: ffff888218f1d078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218f1d078 (&fb_info->lock){+.+.}-{3:3}, at: fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1447 1 lock held by syz-executor.4/11062: #0: ffff888218f1d078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218f1d078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by syz-executor.2/11072: #0: ffff888218f1d078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218f1d078 (&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: 1148 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 11046 Comm: syz-executor.1 Not tainted 5.7.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_pc+0x4a/0x60 kernel/kcov.c:203 Code: 35 8b 90 04 14 00 00 85 d2 74 2b 8b 90 e0 13 00 00 83 fa 02 75 20 48 8b 88 e8 13 00 00 8b 80 e4 13 00 00 48 8b 11 48 83 c2 01 <48> 39 d0 76 07 48 89 34 d1 48 89 11 c3 66 0f 1f 84 00 00 00 00 00 RSP: 0000:ffffc90016cef538 EFLAGS: 00000216 RAX: 0000000000040000 RBX: 0000000000000050 RCX: ffffc9000452d000 RDX: 0000000000040000 RSI: ffffffff83c71366 RDI: 0000000000000004 RBP: 000000000000001a R08: ffff88804cc3a0c0 R09: ffffed10431d31f4 R10: ffff888218e98f9f R11: ffffed10431d31f3 R12: ffff8880000a001a R13: ffff8880000a0000 R14: 0000000000000000 R15: 00000000f1aa1974 FS: 00007fa481be4700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c000465024 CR3: 00000000a6cab000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: writeb arch/x86/include/asm/io.h:65 [inline] vga16fb_fillrect+0x9c6/0x1960 drivers/video/fbdev/vga16fb.c:923 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_set_all_vcs+0x3b3/0x460 drivers/video/fbdev/core/fbcon.c:3038 fbcon_update_vcs+0x26/0x50 drivers/video/fbdev/core/fbcon.c:3045 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:00007fa481be3c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e5240 RCX: 000000000045ca59 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000004 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002fb R14: 00000000004c5797 R15: 00007fa481be46d4