INFO: task syz-executor025:7028 blocked for more than 143 seconds. Not tainted 5.6.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor025 D28496 7028 7026 0x00004004 Call Trace: context_switch kernel/sched/core.c:3378 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4094 schedule+0x188/0x220 kernel/sched/core.c:4168 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4227 __mutex_lock_common+0x129f/0x2fc0 kernel/locking/mutex.c:1033 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 __mutex_lock kernel/locking/mutex.c:1103 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x498/0x580 fs/char_dev.c:414 cd_forget+0x150/0x150 include/linux/spinlock.h:393 do_dentry_open+0x82e/0x10b0 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x2790/0x38b0 fs/namei.c:3346 do_filp_open+0x191/0x3a0 fs/namei.c:3373 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock+0x24/0x40 kernel/locking/spinlock.c:183 spin_unlock include/linux/spinlock.h:393 [inline] __alloc_fd+0x566/0x600 fs/file.c:534 do_sys_openat2+0x463/0x770 fs/open.c:1148 do_sys_open fs/open.c:1164 [inline] __do_sys_openat fs/open.c:1178 [inline] __se_sys_openat fs/open.c:1173 [inline] __x64_sys_openat+0x1c8/0x1f0 fs/open.c:1173 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INFO: task syz-executor025:7029 blocked for more than 143 seconds. Not tainted 5.6.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor025 D28528 7029 7025 0x00004004 Call Trace: context_switch kernel/sched/core.c:3378 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4094 schedule+0x188/0x220 kernel/sched/core.c:4168 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4227 __mutex_lock_common+0x129f/0x2fc0 kernel/locking/mutex.c:1033 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 __mutex_lock kernel/locking/mutex.c:1103 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x498/0x580 fs/char_dev.c:414 cd_forget+0x150/0x150 include/linux/spinlock.h:393 do_dentry_open+0x82e/0x10b0 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x2790/0x38b0 fs/namei.c:3346 do_filp_open+0x191/0x3a0 fs/namei.c:3373 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock+0x24/0x40 kernel/locking/spinlock.c:183 spin_unlock include/linux/spinlock.h:393 [inline] __alloc_fd+0x566/0x600 fs/file.c:534 do_sys_openat2+0x463/0x770 fs/open.c:1148 do_sys_open fs/open.c:1164 [inline] __do_sys_openat fs/open.c:1178 [inline] __se_sys_openat fs/open.c:1173 [inline] __x64_sys_openat+0x1c8/0x1f0 fs/open.c:1173 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INFO: task syz-executor025:7030 blocked for more than 143 seconds. Not tainted 5.6.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor025 D27616 7030 7022 0x00004004 Call Trace: context_switch kernel/sched/core.c:3378 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4094 schedule+0x188/0x220 kernel/sched/core.c:4168 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4227 __mutex_lock_common+0x129f/0x2fc0 kernel/locking/mutex.c:1033 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 __mutex_lock kernel/locking/mutex.c:1103 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x498/0x580 fs/char_dev.c:414 cd_forget+0x150/0x150 include/linux/spinlock.h:393 do_dentry_open+0x82e/0x10b0 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x2790/0x38b0 fs/namei.c:3346 do_filp_open+0x191/0x3a0 fs/namei.c:3373 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock+0x24/0x40 kernel/locking/spinlock.c:183 spin_unlock include/linux/spinlock.h:393 [inline] __alloc_fd+0x566/0x600 fs/file.c:534 do_sys_openat2+0x463/0x770 fs/open.c:1148 do_sys_open fs/open.c:1164 [inline] __do_sys_openat fs/open.c:1178 [inline] __se_sys_openat fs/open.c:1173 [inline] __x64_sys_openat+0x1c8/0x1f0 fs/open.c:1173 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INFO: task syz-executor025:7031 blocked for more than 143 seconds. Not tainted 5.6.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor025 D28352 7031 7027 0x00004004 Call Trace: context_switch kernel/sched/core.c:3378 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4094 schedule+0x188/0x220 kernel/sched/core.c:4168 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4227 __mutex_lock_common+0x129f/0x2fc0 kernel/locking/mutex.c:1033 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 __mutex_lock kernel/locking/mutex.c:1103 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x498/0x580 fs/char_dev.c:414 cd_forget+0x150/0x150 include/linux/spinlock.h:393 do_dentry_open+0x82e/0x10b0 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x2790/0x38b0 fs/namei.c:3346 do_filp_open+0x191/0x3a0 fs/namei.c:3373 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock+0x24/0x40 kernel/locking/spinlock.c:183 spin_unlock include/linux/spinlock.h:393 [inline] __alloc_fd+0x566/0x600 fs/file.c:534 do_sys_openat2+0x463/0x770 fs/open.c:1148 do_sys_open fs/open.c:1164 [inline] __do_sys_openat fs/open.c:1178 [inline] __se_sys_openat fs/open.c:1173 [inline] __x64_sys_openat+0x1c8/0x1f0 fs/open.c:1173 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INFO: task syz-executor025:7032 blocked for more than 143 seconds. Not tainted 5.6.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor025 D27696 7032 7024 0x00004004 Call Trace: context_switch kernel/sched/core.c:3378 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4094 schedule+0x188/0x220 kernel/sched/core.c:4168 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4227 __mutex_lock_common+0x129f/0x2fc0 kernel/locking/mutex.c:1033 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 __mutex_lock kernel/locking/mutex.c:1103 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x498/0x580 fs/char_dev.c:414 cd_forget+0x150/0x150 include/linux/spinlock.h:393 do_dentry_open+0x82e/0x10b0 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x2790/0x38b0 fs/namei.c:3346 do_filp_open+0x191/0x3a0 fs/namei.c:3373 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock+0x24/0x40 kernel/locking/spinlock.c:183 spin_unlock include/linux/spinlock.h:393 [inline] __alloc_fd+0x566/0x600 fs/file.c:534 do_sys_openat2+0x463/0x770 fs/open.c:1148 do_sys_open fs/open.c:1164 [inline] __do_sys_openat fs/open.c:1178 [inline] __se_sys_openat fs/open.c:1173 [inline] __x64_sys_openat+0x1c8/0x1f0 fs/open.c:1173 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Showing all locks held in the system: 1 lock held by khungtaskd/1134: #0: ffffffff892e6c10 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 lib/xarray.c:75 1 lock held by in:imklog/6668: #0: ffff88809fca6630 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x25d/0x2f0 fs/file.c:826 2 locks held by syz-executor025/7023: 1 lock held by syz-executor025/7028: #0: ffff8880a34d2078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a34d2078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by syz-executor025/7029: #0: ffff8880a34d2078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a34d2078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by syz-executor025/7030: #0: ffff8880a34d2078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a34d2078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by syz-executor025/7031: #0: ffff8880a34d2078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a34d2078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by syz-executor025/7032: #0: ffff8880a34d2078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a34d2078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1134 Comm: khungtaskd Not tainted 5.6.0-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+0x1e9/0x30e lib/dump_stack.c:118 nmi_cpu_backtrace+0x9f/0x180 lib/nmi_backtrace.c:101 arch_trigger_cpumask_backtrace+0x10/0x10 arch/x86/kernel/apic/hw_nmi.c:38 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xd2a/0xd40 kernel/hung_task.c:289 kthread+0x353/0x380 kernel/kthread.c:268 hungtask_pm_notify+0x50/0x50 kernel/hung_task.c:265 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1247 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7023 Comm: syz-executor025 Not tainted 5.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__writeq arch/x86/include/asm/io.h:98 [inline] RIP: 0010:bitfill_aligned+0x130/0x1f0 drivers/video/fbdev/core/cfbfillrect.c:64 Code: fd ab fd 44 8b 24 24 48 8b 44 24 18 31 d2 f7 74 24 04 89 c5 bf 07 00 00 00 89 c6 e8 4a 01 ac fd 83 fd 07 76 3b 4c 8b 7c 24 08 <4c> 89 33 4c 89 73 08 4c 89 73 10 4c 89 73 18 4c 89 73 20 4c 89 73 RSP: 0018:ffffc900021678f8 EFLAGS: 00000296 RAX: ffffffff83c75520 RBX: ffff8880000a0200 RCX: ffff888092a04380 RDX: 0000000000000000 RSI: 0000000000000050 RDI: 0000000000000007 RBP: 0000000000000010 R08: ffffffff83c754e6 R09: 0000000000000040 R10: ffff888092a04380 R11: 0000000000000002 R12: 0000000000000000 R13: ffffffffffffffff R14: 0000000000000000 R15: ffffffffffffffff FS: 00000000017f9880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f641f6541f0 CR3: 0000000093d6a000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bitfill_aligned_rev+0x1e0/0x1e0 drivers/video/fbdev/core/cfbfillrect.c:206 cfb_fillrect+0x57b/0x790 drivers/video/fbdev/core/cfbfillrect.c:327 bit_clear_margins+0x37b/0x620 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins drivers/video/fbdev/core/fbcon.c:1381 [inline] fbcon_switch+0x1448/0x1e40 drivers/video/fbdev/core/fbcon.c:2363 redraw_screen+0x4fc/0x16f0 drivers/tty/vt/vt.c:1009 fbcon_modechanged+0x8d5/0xd90 drivers/video/fbdev/core/fbcon.c:3000 fb_set_var+0x822/0xcc0 drivers/video/fbdev/core/fbmem.c:1056 do_fb_ioctl+0x502/0x6f0 drivers/video/fbdev/core/fbmem.c:1109 fb_write+0x540/0x540 drivers/video/fbdev/core/fbmem.c:849 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl fs/ioctl.c:763 [inline] __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:770 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x441419 Code: e8 ac e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffea286b408 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441419 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000003 RBP: 00000000006cb018 R08: 00000000004002c8 R09: 00000000004002c8 R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000402190 R13: 0000000000402220 R14: 0000000000000000 R15: 0000000000000000