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INFO: task hung in do_fb_ioctl

Status: auto-closed as invalid on 2020/05/08 18:42
Reported-by: syzbot+a3d9d9e414f58e012298@syzkaller.appspotmail.com
First crash: 1779d, last: 1779d
▶ ▼ Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in do_fb_ioctl (4) fbdev 1 558d 558d 0/28 auto-obsoleted due to no activity on 2023/07/13 16:33
upstream INFO: task hung in do_fb_ioctl (3) fbdev 2 785d 810d 0/28 auto-obsoleted due to no activity on 2023/01/02 23:29
upstream INFO: task hung in do_fb_ioctl (2) fbdev 1 1005d 1005d 0/28 auto-closed as invalid on 2022/05/22 20:52
upstream INFO: task hung in do_fb_ioctl fbdev 47 1569d 1777d 0/28 closed as dup on 2020/07/27 22:56
linux-4.14 INFO: task hung in do_fb_ioctl C error 24 1458d 1817d 0/1 upstream: reported C repro on 2019/12/03 05:09
linux-4.19 INFO: task hung in do_fb_ioctl (2) C done 7 1189d 1604d 1/1 fixed on 2021/09/21 12:35

Sample crash report:
kobject: 'loop3' (000000004538227c): fill_kobj_path: path = '/devices/virtual/block/loop3'
kobject: 'loop3' (000000004538227c): kobject_uevent_env
kobject: 'loop3' (000000004538227c): fill_kobj_path: path = '/devices/virtual/block/loop3'
kobject: 'kvm' (000000003af06b39): kobject_uevent_env
kobject: 'kvm' (000000003af06b39): fill_kobj_path: path = '/devices/virtual/misc/kvm'
INFO: task syz-executor.2:23764 blocked for more than 140 seconds.
      Not tainted 4.19.94-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D29400 23764   7906 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_timeout+0x8c8/0xfc0 kernel/time/timer.c:1782
 __down_common kernel/locking/semaphore.c:221 [inline]
 __down+0x176/0x2c0 kernel/locking/semaphore.c:238
 down+0x64/0x90 kernel/locking/semaphore.c:62
 console_lock+0x29/0x80 kernel/printk/printk.c:2244
 do_fb_ioctl+0x3e1/0xab0 drivers/video/fbdev/core/fbmem.c:1109
 fb_ioctl+0xe6/0x130 drivers/video/fbdev/core/fbmem.c:1230
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45af49
Code: cc 48 8b 05 71 ce 7e 01 48 85 c0 74 6f 48 8b 05 cd c9 7e 01 48 85 c0 74 63 64 48 8b 04 25 f8 ff ff ff 48 85 c0 74 5a 48 8b 40 <30> 48 85 c0 74 4c 8b 88 38 01 00 00 85 c9 74 42 48 8b 88 c0 00 00
RSP: 002b:00007f5880634c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045af49
RDX: 0000000020000040 RSI: 0000000000004601 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f58806356d4
R13: 00000000004c3903 R14: 00000000004d9f18 R15: 00000000ffffffff
INFO: task syz-executor.2:23779 blocked for more than 140 seconds.
      Not tainted 4.19.94-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D29224 23779   7906 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457
 chrdev_open+0x245/0x6b0 fs/char_dev.c:423
 do_dentry_open+0x4c3/0x1210 fs/open.c:796
 vfs_open+0xa0/0xd0 fs/open.c:905
 do_last fs/namei.c:3418 [inline]
 path_openat+0x10d7/0x45e0 fs/namei.c:3534
 do_filp_open+0x1a1/0x280 fs/namei.c:3564
 do_sys_open+0x3fe/0x550 fs/open.c:1088
 __do_sys_openat fs/open.c:1115 [inline]
 __se_sys_openat fs/open.c:1109 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1109
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45af49
Code: cc 48 8b 05 71 ce 7e 01 48 85 c0 74 6f 48 8b 05 cd c9 7e 01 48 85 c0 74 63 64 48 8b 04 25 f8 ff ff ff 48 85 c0 74 5a 48 8b 40 <30> 48 85 c0 74 4c 8b 88 38 01 00 00 85 c9 74 42 48 8b 88 c0 00 00
RSP: 002b:00007f5880613c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045af49
RDX: 0000000000000000 RSI: 0000000020000000 RDI: ffffffffffffff9c
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f58806146d4
R13: 00000000004c88ce R14: 00000000004e0e30 R15: 00000000ffffffff
INFO: task syz-executor.1:23778 blocked for more than 140 seconds.
      Not tainted 4.19.94-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D29112 23778   7904 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457
 chrdev_open+0x245/0x6b0 fs/char_dev.c:423
 do_dentry_open+0x4c3/0x1210 fs/open.c:796
 vfs_open+0xa0/0xd0 fs/open.c:905
 do_last fs/namei.c:3418 [inline]
 path_openat+0x10d7/0x45e0 fs/namei.c:3534
 do_filp_open+0x1a1/0x280 fs/namei.c:3564
 do_sys_open+0x3fe/0x550 fs/open.c:1088
 __do_sys_openat fs/open.c:1115 [inline]
 __se_sys_openat fs/open.c:1109 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1109
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45af49
Code: cc 48 8b 05 71 ce 7e 01 48 85 c0 74 6f 48 8b 05 cd c9 7e 01 48 85 c0 74 63 64 48 8b 04 25 f8 ff ff ff 48 85 c0 74 5a 48 8b 40 <30> 48 85 c0 74 4c 8b 88 38 01 00 00 85 c9 74 42 48 8b 88 c0 00 00
RSP: 002b:00007ff131727c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045af49
RDX: 0000000000000000 RSI: 0000000020000000 RDI: ffffffffffffff9c
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff1317286d4
R13: 00000000004c88ce R14: 00000000004e0e30 R15: 00000000ffffffff
INFO: task syz-executor.5:23757 blocked for more than 140 seconds.
      Not tainted 4.19.94-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D28216 23757   7920 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 fb_release+0x55/0x150 drivers/video/fbdev/core/fbmem.c:1486
 __fput+0x2dd/0x8b0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:167
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x414ae1
Code: 60 89 44 24 10 8b 44 24 64 83 c8 10 89 44 24 14 8b 44 24 68 89 44 24 18 8b 44 24 6c 89 44 24 1c e8 74 d7 fe ff 48 8b 44 24 20 <48> 8b 4c 24 28 e9 72 ff ff ff 48 8b 44 24 38 48 89 04 24 48 8b 44
RSP: 002b:00007ffda81dbf70 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000414ae1
RDX: 0000001b32920000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000001 R08: 0000000068919a43 R09: 0000000068919a47
R10: 00007ffda81dc050 R11: 0000000000000293 R12: 000000000075bf20
R13: 00000000001026fa R14: 0000000000760768 R15: 000000000075bf2c
INFO: task syz-executor.3:23772 blocked for more than 140 seconds.
      Not tainted 4.19.94-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D28632 23772   7910 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457
 chrdev_open+0x245/0x6b0 fs/char_dev.c:423
 do_dentry_open+0x4c3/0x1210 fs/open.c:796
 vfs_open+0xa0/0xd0 fs/open.c:905
 do_last fs/namei.c:3418 [inline]
 path_openat+0x10d7/0x45e0 fs/namei.c:3534
 do_filp_open+0x1a1/0x280 fs/namei.c:3564
 do_sys_open+0x3fe/0x550 fs/open.c:1088
 __do_sys_openat fs/open.c:1115 [inline]
 __se_sys_openat fs/open.c:1109 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1109
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45af49
Code: cc 48 8b 05 71 ce 7e 01 48 85 c0 74 6f 48 8b 05 cd c9 7e 01 48 85 c0 74 63 64 48 8b 04 25 f8 ff ff ff 48 85 c0 74 5a 48 8b 40 <30> 48 85 c0 74 4c 8b 88 38 01 00 00 85 c9 74 42 48 8b 88 c0 00 00
RSP: 002b:00007fa39cdd4c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045af49
RDX: 0000000000000000 RSI: 0000000020000000 RDI: ffffffffffffff9c
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa39cdd56d4
R13: 00000000004c88ce R14: 00000000004e0e30 R15: 00000000ffffffff
INFO: task syz-executor.3:23777 blocked for more than 140 seconds.
      Not tainted 4.19.94-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D29224 23777   7910 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457
 chrdev_open+0x245/0x6b0 fs/char_dev.c:423
 do_dentry_open+0x4c3/0x1210 fs/open.c:796
 vfs_open+0xa0/0xd0 fs/open.c:905
 do_last fs/namei.c:3418 [inline]
 path_openat+0x10d7/0x45e0 fs/namei.c:3534
 do_filp_open+0x1a1/0x280 fs/namei.c:3564
 do_sys_open+0x3fe/0x550 fs/open.c:1088
 __do_sys_openat fs/open.c:1115 [inline]
 __se_sys_openat fs/open.c:1109 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1109
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45af49
Code: cc 48 8b 05 71 ce 7e 01 48 85 c0 74 6f 48 8b 05 cd c9 7e 01 48 85 c0 74 63 64 48 8b 04 25 f8 ff ff ff 48 85 c0 74 5a 48 8b 40 <30> 48 85 c0 74 4c 8b 88 38 01 00 00 85 c9 74 42 48 8b 88 c0 00 00
RSP: 002b:00007fa39cdb3c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045af49
RDX: 0000000000000000 RSI: 0000000020000000 RDI: ffffffffffffff9c
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa39cdb46d4
R13: 00000000004c88ce R14: 00000000004e0e30 R15: 00000000ffffffff
INFO: task syz-executor.0:23771 blocked for more than 140 seconds.
      Not tainted 4.19.94-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D29224 23771   8465 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457
 chrdev_open+0x245/0x6b0 fs/char_dev.c:423
 do_dentry_open+0x4c3/0x1210 fs/open.c:796
 vfs_open+0xa0/0xd0 fs/open.c:905
 do_last fs/namei.c:3418 [inline]
 path_openat+0x10d7/0x45e0 fs/namei.c:3534
 do_filp_open+0x1a1/0x280 fs/namei.c:3564
 do_sys_open+0x3fe/0x550 fs/open.c:1088
 __do_sys_openat fs/open.c:1115 [inline]
 __se_sys_openat fs/open.c:1109 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1109
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45af49
Code: cc 48 8b 05 71 ce 7e 01 48 85 c0 74 6f 48 8b 05 cd c9 7e 01 48 85 c0 74 63 64 48 8b 04 25 f8 ff ff ff 48 85 c0 74 5a 48 8b 40 <30> 48 85 c0 74 4c 8b 88 38 01 00 00 85 c9 74 42 48 8b 88 c0 00 00
RSP: 002b:00007fa57a2dcc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045af49
RDX: 0000000000000000 RSI: 0000000020000000 RDI: ffffffffffffff9c
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa57a2dd6d4
R13: 00000000004c88ce R14: 00000000004e0e30 R15: 00000000ffffffff
INFO: task syz-executor.0:23776 blocked for more than 140 seconds.
      Not tainted 4.19.94-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D29224 23776   8465 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457
 chrdev_open+0x245/0x6b0 fs/char_dev.c:423
 do_dentry_open+0x4c3/0x1210 fs/open.c:796
 vfs_open+0xa0/0xd0 fs/open.c:905
 do_last fs/namei.c:3418 [inline]
 path_openat+0x10d7/0x45e0 fs/namei.c:3534
 do_filp_open+0x1a1/0x280 fs/namei.c:3564
 do_sys_open+0x3fe/0x550 fs/open.c:1088
 __do_sys_openat fs/open.c:1115 [inline]
 __se_sys_openat fs/open.c:1109 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1109
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45af49
Code: cc 48 8b 05 71 ce 7e 01 48 85 c0 74 6f 48 8b 05 cd c9 7e 01 48 85 c0 74 63 64 48 8b 04 25 f8 ff ff ff 48 85 c0 74 5a 48 8b 40 <30> 48 85 c0 74 4c 8b 88 38 01 00 00 85 c9 74 42 48 8b 88 c0 00 00
RSP: 002b:00007fa57a2bbc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045af49
RDX: 0000000000000000 RSI: 0000000020000000 RDI: ffffffffffffff9c
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa57a2bc6d4
R13: 00000000004c88ce R14: 00000000004e0e30 R15: 00000000ffffffff
INFO: task syz-executor.4:23770 blocked for more than 140 seconds.
      Not tainted 4.19.94-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D29224 23770   7914 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457
 chrdev_open+0x245/0x6b0 fs/char_dev.c:423
 do_dentry_open+0x4c3/0x1210 fs/open.c:796
 vfs_open+0xa0/0xd0 fs/open.c:905
 do_last fs/namei.c:3418 [inline]
 path_openat+0x10d7/0x45e0 fs/namei.c:3534
 do_filp_open+0x1a1/0x280 fs/namei.c:3564
 do_sys_open+0x3fe/0x550 fs/open.c:1088
 __do_sys_openat fs/open.c:1115 [inline]
 __se_sys_openat fs/open.c:1109 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1109
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45af49
Code: cc 48 8b 05 71 ce 7e 01 48 85 c0 74 6f 48 8b 05 cd c9 7e 01 48 85 c0 74 63 64 48 8b 04 25 f8 ff ff ff 48 85 c0 74 5a 48 8b 40 <30> 48 85 c0 74 4c 8b 88 38 01 00 00 85 c9 74 42 48 8b 88 c0 00 00
RSP: 002b:00007fec9a779c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045af49
RDX: 0000000000000000 RSI: 0000000020000000 RDI: ffffffffffffff9c
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fec9a77a6d4
R13: 00000000004c88ce R14: 00000000004e0e30 R15: 00000000ffffffff
INFO: task syz-executor.4:23775 blocked for more than 140 seconds.
      Not tainted 4.19.94-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D29112 23775   7914 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457
 chrdev_open+0x245/0x6b0 fs/char_dev.c:423
 do_dentry_open+0x4c3/0x1210 fs/open.c:796
 vfs_open+0xa0/0xd0 fs/open.c:905
 do_last fs/namei.c:3418 [inline]
 path_openat+0x10d7/0x45e0 fs/namei.c:3534
 do_filp_open+0x1a1/0x280 fs/namei.c:3564
 do_sys_open+0x3fe/0x550 fs/open.c:1088
 __do_sys_openat fs/open.c:1115 [inline]
 __se_sys_openat fs/open.c:1109 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1109
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45af49
Code: Bad RIP value.
RSP: 002b:00007fec9a758c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045af49
RDX: 0000000000000000 RSI: 0000000020000000 RDI: ffffffffffffff9c
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fec9a7596d4
R13: 00000000004c88ce R14: 00000000004e0e30 R15: 00000000ffffffff

Showing all locks held in the system:
1 lock held by khungtaskd/1082:
 #0: 00000000548d1535 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438
1 lock held by khugepaged/1089:
1 lock held by rsyslogd/7740:
 #0: 00000000748d92ec (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767
2 locks held by getty/7861:
 #0: 000000007b3fd7fb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000004771156e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7862:
 #0: 00000000cc45ad99 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000006624e47e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7863:
 #0: 00000000932d987c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000be95329e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7864:
 #0: 000000007d00374f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000002f3e1ec2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7865:
 #0: 0000000030dad7d7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000004d8b4203 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7866:
 #0: 000000001cc40f31 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000037e5611 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/7867:
 #0: 00000000e9e4cfae (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000f6b77800 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
1 lock held by syz-executor.2/23779:
 #0: 0000000017c41aab (&fb_info->lock){+.+.}, at: fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457
3 locks held by syz-executor.1/23763:
1 lock held by syz-executor.1/23778:
 #0: 0000000017c41aab (&fb_info->lock){+.+.}, at: fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457
1 lock held by syz-executor.5/23757:
 #0: 0000000017c41aab (&fb_info->lock){+.+.}, at: fb_release+0x55/0x150 drivers/video/fbdev/core/fbmem.c:1486
1 lock held by syz-executor.3/23772:
 #0: 0000000017c41aab (&fb_info->lock){+.+.}, at: fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457
1 lock held by syz-executor.3/23777:
 #0: 0000000017c41aab (&fb_info->lock){+.+.}, at: fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457
1 lock held by syz-executor.0/23771:
 #0: 0000000017c41aab (&fb_info->lock){+.+.}, at: fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457
1 lock held by syz-executor.0/23776:
 #0: 0000000017c41aab (&fb_info->lock){+.+.}, at: fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457
1 lock held by syz-executor.4/23770:
 #0: 0000000017c41aab (&fb_info->lock){+.+.}, at: fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457
1 lock held by syz-executor.4/23775:
 #0: 0000000017c41aab (&fb_info->lock){+.+.}, at: fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 1082 Comm: khungtaskd Not tainted 4.19.94-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+0x197/0x210 lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
 watchdog+0x9df/0xee0 kernel/hung_task.c:287
 kthread+0x354/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 23763 Comm: syz-executor.1 Not tainted 4.19.94-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:44 [inline]
RIP: 0010:bitfill_aligned+0x39/0x210 drivers/video/fbdev/core/cfbfillrect.c:35
Code: 55 45 89 cd 41 54 45 89 c4 53 48 89 cb 48 83 ec 18 e8 8b df df fd 31 ff 44 89 e6 e8 01 e1 df fd 45 85 e4 74 79 e8 77 df df fd <43> 8d 3c 3c 44 89 f9 31 d2 48 c7 c6 ff ff ff ff 89 7d c4 48 89 f0
RSP: 0018:ffff8880644a7160 EFLAGS: 00000246
RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc90008097000
RDX: 0000000000040000 RSI: ffffffff838b6579 RDI: 0000000000000005
RBP: ffff8880644a71a0 R08: ffff888063d64040 R09: 0000000000000040
R10: ffffed10432ac1cb R11: ffff888219560e5f R12: 0000000000000040
R13: 0000000000000040 R14: ffff8880000a0000 R15: 0000000000000000
FS:  00007ff131749700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 000000004e121000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 cfb_fillrect+0x423/0x7c0 drivers/video/fbdev/core/cfbfillrect.c:327
 vga16fb_fillrect+0x6ce/0x19b0 drivers/video/fbdev/vga16fb.c:951
 bit_clear_margins+0x30b/0x530 drivers/video/fbdev/core/bitblit.c:232
 fbcon_clear_margins+0x2e3/0x370 drivers/video/fbdev/core/fbcon.c:1339
 fbcon_switch+0xe7d/0x1a40 drivers/video/fbdev/core/fbcon.c:2321
 redraw_screen+0x37d/0x8e0 drivers/tty/vt/vt.c:997
 fbcon_modechanged+0x5f3/0x900 drivers/video/fbdev/core/fbcon.c:2969
 fbcon_event_notify+0x1bd/0x1dba drivers/video/fbdev/core/fbcon.c:3344
 notifier_call_chain+0xc2/0x230 kernel/notifier.c:93
 __blocking_notifier_call_chain kernel/notifier.c:317 [inline]
 __blocking_notifier_call_chain kernel/notifier.c:304 [inline]
 blocking_notifier_call_chain kernel/notifier.c:328 [inline]
 blocking_notifier_call_chain+0x94/0xb0 kernel/notifier.c:325
 fb_notifier_call_chain+0x25/0x30 drivers/video/fbdev/core/fb_notify.c:45
 fb_set_var+0xc8f/0xe80 drivers/video/fbdev/core/fbmem.c:1042
 do_fb_ioctl+0x450/0xab0 drivers/video/fbdev/core/fbmem.c:1115
 fb_ioctl+0xe6/0x130 drivers/video/fbdev/core/fbmem.c:1230
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45af49
Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ff131748c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045af49
RDX: 0000000020000040 RSI: 0000000000004601 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff1317496d4
R13: 00000000004c3903 R14: 00000000004d9f18 R15: 00000000ffffffff

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/01/09 18:40 linux-4.19.y cb1f9a169a0e 4de4e9f0 .config console log report ci2-linux-4-19
* Struck through repros no longer work on HEAD.