syzbot


INFO: task hung in fb_release
Status: auto-closed as invalid on 2020/11/15 14:18
Reported-by: syzbot+9643afdc01eac6585374@syzkaller.appspotmail.com
First crash: 860d, last: 673d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in fb_release C done 64 648d 882d 0/22 closed as dup on 2020/07/27 23:00
linux-4.14 INFO: task hung in fb_release C done 48 664d 895d 1/1 fixed on 2020/08/28 16:06

Sample crash report:
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
NOHZ: local_softirq_pending 08
INFO: task syz-executor.5:7848 blocked for more than 140 seconds.
      Not tainted 4.19.133-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D28032  7848   6866 0x00000006
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x647/0x1260 kernel/locking/mutex.c:1072
 fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1486
 __fput+0x2ce/0x890 fs/file_table.c:278
 task_work_run+0x148/0x1c0 kernel/task_work.c:113
 get_signal+0x1b64/0x1f70 kernel/signal.c:2399
 do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:821
 exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c1d9
Code: 18 0f 57 c0 0f 11 44 24 20 48 c7 44 24 30 64 00 00 00 0f 11 44 24 38 48 89 5c 24 48 e8 c0 dc ff ff 48 8b 44 24 50 48 85 c0 75 <12> 48 8b 8c 24 c8 01 00 00 0f ba e1 00 0f 83 13 01 00 00 48 83 f8
RSP: 002b:00007fc922260c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 000000000000ce80 RCX: 000000000045c1d9
RDX: 0000000020000200 RSI: 0000000000004601 RDI: 0000000000000007
RBP: 000000000078bfe0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bfac
R13: 00007ffec7ba0caf R14: 00007fc9222619c0 R15: 000000000078bfac
INFO: task syz-executor.5:7889 blocked for more than 140 seconds.
      Not tainted 4.19.133-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D29496  7889   6866 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_timeout+0x90e/0xef0 kernel/time/timer.c:1782
 __down_common kernel/locking/semaphore.c:221 [inline]
 __down+0x183/0x2a0 kernel/locking/semaphore.c:238
 down+0x57/0x80 kernel/locking/semaphore.c:62
 console_lock+0x25/0x80 kernel/printk/printk.c:2244
 do_fb_ioctl+0x33e/0xb50 drivers/video/fbdev/core/fbmem.c:1109
 fb_ioctl+0xdd/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+0xcdb/0x12e0 fs/ioctl.c:688
 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c1d9
Code: 18 0f 57 c0 0f 11 44 24 20 48 c7 44 24 30 64 00 00 00 0f 11 44 24 38 48 89 5c 24 48 e8 c0 dc ff ff 48 8b 44 24 50 48 85 c0 75 <12> 48 8b 8c 24 c8 01 00 00 0f ba e1 00 0f 83 13 01 00 00 48 83 f8
RSP: 002b:00007fc9221dcc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000000ce80 RCX: 000000000045c1d9
RDX: 0000000020000200 RSI: 0000000000004601 RDI: 0000000000000006
RBP: 000000000078c260 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078c22c
R13: 00007ffec7ba0caf R14: 00007fc9221dd9c0 R15: 000000000078c22c
INFO: task syz-executor.5:7890 blocked for more than 140 seconds.
      Not tainted 4.19.133-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D29496  7890   6866 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_timeout+0x90e/0xef0 kernel/time/timer.c:1782
 __down_common kernel/locking/semaphore.c:221 [inline]
 __down+0x183/0x2a0 kernel/locking/semaphore.c:238
 down+0x57/0x80 kernel/locking/semaphore.c:62
 console_lock+0x25/0x80 kernel/printk/printk.c:2244
 do_fb_ioctl+0x33e/0xb50 drivers/video/fbdev/core/fbmem.c:1109
 fb_ioctl+0xdd/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+0xcdb/0x12e0 fs/ioctl.c:688
 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c1d9
Code: 18 0f 57 c0 0f 11 44 24 20 48 c7 44 24 30 64 00 00 00 0f 11 44 24 38 48 89 5c 24 48 e8 c0 dc ff ff 48 8b 44 24 50 48 85 c0 75 <12> 48 8b 8c 24 c8 01 00 00 0f ba e1 00 0f 83 13 01 00 00 48 83 f8
RSP: 002b:00007fc9221bbc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000000ce80 RCX: 000000000045c1d9
RDX: 0000000020000200 RSI: 0000000000004601 RDI: 0000000000000007
RBP: 000000000078c300 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078c2cc
R13: 00007ffec7ba0caf R14: 00007fc9221bc9c0 R15: 000000000078c2cc
INFO: task syz-executor.4:7886 blocked for more than 140 seconds.
      Not tainted 4.19.133-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D29496  7886   6851 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_timeout+0x90e/0xef0 kernel/time/timer.c:1782
 __down_common kernel/locking/semaphore.c:221 [inline]
 __down+0x183/0x2a0 kernel/locking/semaphore.c:238
 down+0x57/0x80 kernel/locking/semaphore.c:62
 console_lock+0x25/0x80 kernel/printk/printk.c:2244
 do_fb_ioctl+0x33e/0xb50 drivers/video/fbdev/core/fbmem.c:1109
 fb_ioctl+0xdd/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+0xcdb/0x12e0 fs/ioctl.c:688
 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c1d9
Code: 18 0f 57 c0 0f 11 44 24 20 48 c7 44 24 30 64 00 00 00 0f 11 44 24 38 48 89 5c 24 48 e8 c0 dc ff ff 48 8b 44 24 50 48 85 c0 75 <12> 48 8b 8c 24 c8 01 00 00 0f ba e1 00 0f 83 13 01 00 00 48 83 f8
RSP: 002b:00007fe440e40c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000000ce80 RCX: 000000000045c1d9
RDX: 0000000020000200 RSI: 0000000000004601 RDI: 0000000000000006
RBP: 000000000078bfe0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bfac
R13: 00007ffe0bb5136f R14: 00007fe440e419c0 R15: 000000000078bfac
INFO: task syz-executor.4:7888 blocked for more than 140 seconds.
      Not tainted 4.19.133-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D28952  7888   6851 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_timeout+0x90e/0xef0 kernel/time/timer.c:1782
 __down_common kernel/locking/semaphore.c:221 [inline]
 __down+0x183/0x2a0 kernel/locking/semaphore.c:238
 down+0x57/0x80 kernel/locking/semaphore.c:62
 console_lock+0x25/0x80 kernel/printk/printk.c:2244
 do_fb_ioctl+0x33e/0xb50 drivers/video/fbdev/core/fbmem.c:1109
 fb_ioctl+0xdd/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+0xcdb/0x12e0 fs/ioctl.c:688
 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c1d9
Code: 18 0f 57 c0 0f 11 44 24 20 48 c7 44 24 30 64 00 00 00 0f 11 44 24 38 48 89 5c 24 48 e8 c0 dc ff ff 48 8b 44 24 50 48 85 c0 75 <12> 48 8b 8c 24 c8 01 00 00 0f ba e1 00 0f 83 13 01 00 00 48 83 f8
RSP: 002b:00007fe440dfec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000000ce80 RCX: 000000000045c1d9
RDX: 0000000020000200 RSI: 0000000000004601 RDI: 0000000000000006
RBP: 000000000078c120 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078c0ec
R13: 00007ffe0bb5136f R14: 00007fe440dff9c0 R15: 000000000078c0ec
INFO: task syz-executor.3:7913 blocked for more than 140 seconds.
      Not tainted 4.19.133-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D29520  7913   6762 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x647/0x1260 kernel/locking/mutex.c:1072
 fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457
 chrdev_open+0x266/0x770 fs/char_dev.c:423
 do_dentry_open+0x4aa/0x1160 fs/open.c:796
 do_last fs/namei.c:3421 [inline]
 path_openat+0x793/0x2df0 fs/namei.c:3537
 do_filp_open+0x18c/0x3f0 fs/namei.c:3567
 do_sys_open+0x3b3/0x520 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c1d9
Code: 18 0f 57 c0 0f 11 44 24 20 48 c7 44 24 30 64 00 00 00 0f 11 44 24 38 48 89 5c 24 48 e8 c0 dc ff ff 48 8b 44 24 50 48 85 c0 75 <12> 48 8b 8c 24 c8 01 00 00 0f ba e1 00 0f 83 13 01 00 00 48 83 f8
RSP: 002b:00007f79b54eec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000020880 RCX: 000000000045c1d9
RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 000000000078bf48 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007fff91f63baf R14: 00007f79b54ef9c0 R15: 000000000078bf0c
INFO: task syz-executor.3:7916 blocked for more than 140 seconds.
      Not tainted 4.19.133-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D28152  7916   6762 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x647/0x1260 kernel/locking/mutex.c:1072
 fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457
 chrdev_open+0x266/0x770 fs/char_dev.c:423
 do_dentry_open+0x4aa/0x1160 fs/open.c:796
 do_last fs/namei.c:3421 [inline]
 path_openat+0x793/0x2df0 fs/namei.c:3537
 do_filp_open+0x18c/0x3f0 fs/namei.c:3567
 do_sys_open+0x3b3/0x520 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c1d9
Code: 18 0f 57 c0 0f 11 44 24 20 48 c7 44 24 30 64 00 00 00 0f 11 44 24 38 48 89 5c 24 48 e8 c0 dc ff ff 48 8b 44 24 50 48 85 c0 75 <12> 48 8b 8c 24 c8 01 00 00 0f ba e1 00 0f 83 13 01 00 00 48 83 f8
RSP: 002b:00007f79b54cdc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000020880 RCX: 000000000045c1d9
RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 000000000078bfe8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bfac
R13: 00007fff91f63baf R14: 00007f79b54ce9c0 R15: 000000000078bfac
INFO: task syz-executor.0:7919 blocked for more than 140 seconds.
      Not tainted 4.19.133-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D29464  7919   6464 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x647/0x1260 kernel/locking/mutex.c:1072
 fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457
 chrdev_open+0x266/0x770 fs/char_dev.c:423
 do_dentry_open+0x4aa/0x1160 fs/open.c:796
 do_last fs/namei.c:3421 [inline]
 path_openat+0x793/0x2df0 fs/namei.c:3537
 do_filp_open+0x18c/0x3f0 fs/namei.c:3567
 do_sys_open+0x3b3/0x520 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c1d9
Code: 18 0f 57 c0 0f 11 44 24 20 48 c7 44 24 30 64 00 00 00 0f 11 44 24 38 48 89 5c 24 48 e8 c0 dc ff ff 48 8b 44 24 50 48 85 c0 75 <12> 48 8b 8c 24 c8 01 00 00 0f ba e1 00 0f 83 13 01 00 00 48 83 f8
RSP: 002b:00007fbee6d92c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000020880 RCX: 000000000045c1d9
RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 000000000078bf48 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007fffca122b9f R14: 00007fbee6d939c0 R15: 000000000078bf0c
INFO: task syz-executor.0:7933 blocked for more than 140 seconds.
      Not tainted 4.19.133-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D29520  7933   6464 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x647/0x1260 kernel/locking/mutex.c:1072
 fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457
 chrdev_open+0x266/0x770 fs/char_dev.c:423
 do_dentry_open+0x4aa/0x1160 fs/open.c:796
 do_last fs/namei.c:3421 [inline]
 path_openat+0x793/0x2df0 fs/namei.c:3537
 do_filp_open+0x18c/0x3f0 fs/namei.c:3567
 do_sys_open+0x3b3/0x520 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c1d9
Code: 18 0f 57 c0 0f 11 44 24 20 48 c7 44 24 30 64 00 00 00 0f 11 44 24 38 48 89 5c 24 48 e8 c0 dc ff ff 48 8b 44 24 50 48 85 c0 75 <12> 48 8b 8c 24 c8 01 00 00 0f ba e1 00 0f 83 13 01 00 00 48 83 f8
RSP: 002b:00007fbee6d50c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000020880 RCX: 000000000045c1d9
RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 000000000078c088 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078c04c
R13: 00007fffca122b9f R14: 00007fbee6d519c0 R15: 000000000078c04c
INFO: task syz-executor.1:7924 blocked for more than 140 seconds.
      Not tainted 4.19.133-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D28256  7924   6582 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3515
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0x647/0x1260 kernel/locking/mutex.c:1072
 fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457
 chrdev_open+0x266/0x770 fs/char_dev.c:423
 do_dentry_open+0x4aa/0x1160 fs/open.c:796
 do_last fs/namei.c:3421 [inline]
 path_openat+0x793/0x2df0 fs/namei.c:3537
 do_filp_open+0x18c/0x3f0 fs/namei.c:3567
 do_sys_open+0x3b3/0x520 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c1d9
Code: 18 0f 57 c0 0f 11 44 24 20 48 c7 44 24 30 64 00 00 00 0f 11 44 24 38 48 89 5c 24 48 e8 c0 dc ff ff 48 8b 44 24 50 48 85 c0 75 <12> 48 8b 8c 24 c8 01 00 00 0f ba e1 00 0f 83 13 01 00 00 48 83 f8
RSP: 002b:00007fe984891c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000020880 RCX: 000000000045c1d9
RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 000000000078bf48 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007ffee904a0bf R14: 00007fe9848929c0 R15: 000000000078bf0c

Showing all locks held in the system:
1 lock held by khungtaskd/1075:
 #0: 00000000aa95fb92 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440
1 lock held by in:imklog/6141:
 #0: 00000000c636e3d0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767
1 lock held by syz-executor.5/7848:
 #0: 0000000058b60574 (&fb_info->lock){+.+.}, at: fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1486
3 locks held by syz-executor.2/7874:
1 lock held by syz-executor.3/7913:
 #0: 0000000058b60574 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457
1 lock held by syz-executor.3/7916:
 #0: 0000000058b60574 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457
1 lock held by syz-executor.0/7919:
 #0: 0000000058b60574 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457
1 lock held by syz-executor.0/7933:
 #0: 0000000058b60574 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457
1 lock held by syz-executor.1/7924:
 #0: 0000000058b60574 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457
1 lock held by syz-executor.1/7928:
 #0: 0000000058b60574 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457

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

NMI backtrace for cpu 1
CPU: 1 PID: 1075 Comm: khungtaskd Not tainted 4.19.133-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+0x1fc/0x2fe lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
 watchdog+0x991/0xe60 kernel/hung_task.c:287
 kthread+0x30b/0x410 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7874 Comm: syz-executor.2 Not tainted 4.19.133-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:193 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:69 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x1c/0x50 kernel/kcov.c:101
Code: 76 f4 26 0a 00 00 00 00 e9 39 ec ff ff 90 48 8b 34 24 65 48 8b 04 25 40 ee 01 00 65 8b 15 ec 44 98 7e 81 e2 00 01 1f 00 75 2b <8b> 90 d8 12 00 00 83 fa 02 75 20 48 8b 88 e0 12 00 00 8b 80 dc 12
RSP: 0018:ffff88804d2d72b8 EFLAGS: 00000246
RAX: ffff88804b38c0c0 RBX: 0000000000000050 RCX: ffffffff8385d7e4
RDX: 0000000000000000 RSI: ffffffff8385d7d0 RDI: 0000000000000004
RBP: 0000000000000040 R08: 0000000000000001 R09: 0000000000000050
R10: 0000000000000004 R11: 0000000000000000 R12: ffff8880000a0040
R13: ffff8880000a0000 R14: 0000000000000000 R15: 00000000f0543124
FS:  00007f8141154700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3d62dac000 CR3: 000000009b371000 CR4: 00000000001406f0
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+0x9c0/0x1940 drivers/video/fbdev/vga16fb.c:923
 bit_clear_margins+0x2d5/0x4a0 drivers/video/fbdev/core/bitblit.c:232
 fbcon_clear_margins+0x1e2/0x350 drivers/video/fbdev/core/fbcon.c:1342
 fbcon_switch+0x1038/0x1d26 drivers/video/fbdev/core/fbcon.c:2324
 redraw_screen+0x37d/0x870 drivers/tty/vt/vt.c:1015
 fbcon_modechanged+0x6e9/0x9f0 drivers/video/fbdev/core/fbcon.c:2972
 fbcon_event_notify+0x197/0x1d80 drivers/video/fbdev/core/fbcon.c:3347
 notifier_call_chain+0xc0/0x230 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+0x85/0xa0 kernel/notifier.c:325
 fb_set_var+0xc51/0xe20 drivers/video/fbdev/core/fbmem.c:1042
 do_fb_ioctl+0x3cf/0xb50 drivers/video/fbdev/core/fbmem.c:1115
 fb_ioctl+0xdd/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+0xcdb/0x12e0 fs/ioctl.c:688
 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c1d9
Code: 8d 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 5b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f8141153c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000000ce80 RCX: 000000000045c1d9
RDX: 0000000020000200 RSI: 0000000000004601 RDI: 000000000000000a
RBP: 000000000078c120 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078c0ec
R13: 00007ffff49bc72f R14: 00007f81411549c0 R15: 000000000078c0ec

Crashes (10):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-19 2020/07/18 14:17 linux-4.19.y 17a87580a885 9c812472 .config log report
ci2-linux-4-19 2020/07/09 01:02 linux-4.19.y 399849e4654e 9f9845eb .config log report
ci2-linux-4-19 2020/06/16 07:35 linux-4.19.y 3fc898571b97 baca2611 .config log report
ci2-linux-4-19 2020/05/05 01:22 linux-4.19.y fdc072324f3c 9941337c .config log report
ci2-linux-4-19 2020/04/01 20:15 linux-4.19.y 54b4fa6d3955 a34e2c33 .config log report
ci2-linux-4-19 2020/03/02 18:43 linux-4.19.y a083db76118d 4a4e0509 .config log report
ci2-linux-4-19 2020/02/04 11:34 linux-4.19.y 32ee7492f104 93e5e335 .config log report
ci2-linux-4-19 2020/01/30 21:59 linux-4.19.y 7cdefde351b6 5ed23f9a .config log report
ci2-linux-4-19 2020/01/14 16:54 linux-4.19.y dcd888983542 32881205 .config log report
ci2-linux-4-19 2020/01/13 20:37 linux-4.19.y dcd888983542 99565c1a .config log report