syzbot


INFO: task hung in tty_release_struct

Status: auto-closed as invalid on 2020/08/28 17:40
Reported-by: syzbot+14edf875449ce6074b55@syzkaller.appspotmail.com
First crash: 900d, last: 790d
similar bugs (4):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in tty_release_struct 2 714d 721d 0/22 auto-closed as invalid on 2020/10/13 06:21
upstream INFO: task hung in tty_release_struct (2) 7 148d 284d 0/22 closed as invalid on 2022/02/07 19:19
upstream INFO: task hung in tty_release_struct (3) 3 90d 134d 0/22 auto-closed as invalid on 2022/06/29 20:46
android-414 INFO: task hung in tty_release_struct 7 1295d 1173d 0/1 auto-closed as invalid on 2019/06/10 11:00

Sample crash report:
base_sock_release(ffff888042d434c0) sk=ffff888059fbc340
INFO: task syz-executor.0:9939 blocked for more than 140 seconds.
      Not tainted 4.14.177-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D28576  9939   6348 0x80000002
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
 tty_release_struct+0x2c/0x50 drivers/tty/tty_io.c:1615
 tty_release+0xaa6/0xd60 drivers/tty/tty_io.c:1776
 __fput+0x25f/0x790 fs/file_table.c:210
 task_work_run+0x113/0x190 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x9f2/0x2b00 kernel/exit.c:858
 do_group_exit+0x100/0x310 kernel/exit.c:955
 get_signal+0x385/0x1ca0 kernel/signal.c:2423
 do_signal+0x7c/0x1690 arch/x86/kernel/signal.c:814
 exit_to_usermode_loop+0x159/0x220 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c829
RSP: 002b:00007fad78365cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000078bf08 RCX: 000000000045c829
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000078bf08
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007ffe260b7faf R14: 00007fad783669c0 R15: 000000000078bf0c
INFO: task syz-executor.0:9945 blocked for more than 140 seconds.
      Not tainted 4.14.177-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D28576  9945   6348 0x80000002
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
 tty_release_struct+0x2c/0x50 drivers/tty/tty_io.c:1615
 tty_release+0xaa6/0xd60 drivers/tty/tty_io.c:1776
 __fput+0x25f/0x790 fs/file_table.c:210
 task_work_run+0x113/0x190 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x9f2/0x2b00 kernel/exit.c:858
 do_group_exit+0x100/0x310 kernel/exit.c:955
 get_signal+0x385/0x1ca0 kernel/signal.c:2423
 do_signal+0x7c/0x1690 arch/x86/kernel/signal.c:814
 exit_to_usermode_loop+0x159/0x220 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c829
RSP: 002b:00007fad78365cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000078bf08 RCX: 000000000045c829
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000078bf08
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007ffe260b7faf R14: 00007fad783669c0 R15: 000000000078bf0c
INFO: task syz-executor.0:9949 blocked for more than 140 seconds.
      Not tainted 4.14.177-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D28496  9949   6348 0x80000002
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
 tty_release_struct+0x2c/0x50 drivers/tty/tty_io.c:1615
 tty_release+0xaa6/0xd60 drivers/tty/tty_io.c:1776
 __fput+0x25f/0x790 fs/file_table.c:210
 task_work_run+0x113/0x190 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x9f2/0x2b00 kernel/exit.c:858
 do_group_exit+0x100/0x310 kernel/exit.c:955
 get_signal+0x385/0x1ca0 kernel/signal.c:2423
 do_signal+0x7c/0x1690 arch/x86/kernel/signal.c:814
 exit_to_usermode_loop+0x159/0x220 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c829
RSP: 002b:00007fad78365cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000078bf08 RCX: 000000000045c829
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000078bf08
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007ffe260b7faf R14: 00007fad783669c0 R15: 000000000078bf0c
INFO: task syz-executor.4:17462 blocked for more than 140 seconds.
      Not tainted 4.14.177-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D28576 17462   6357 0x80000002
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
 tty_release_struct+0x2c/0x50 drivers/tty/tty_io.c:1615
 tty_release+0xaa6/0xd60 drivers/tty/tty_io.c:1776
 __fput+0x25f/0x790 fs/file_table.c:210
 task_work_run+0x113/0x190 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x9f2/0x2b00 kernel/exit.c:858
 do_group_exit+0x100/0x310 kernel/exit.c:955
 get_signal+0x385/0x1ca0 kernel/signal.c:2423
 do_signal+0x7c/0x1690 arch/x86/kernel/signal.c:814
 exit_to_usermode_loop+0x159/0x220 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c829
RSP: 002b:00007fccffcc2cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000078c048 RCX: 000000000045c829
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000078c048
RBP: 000000000078c040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078c04c
R13: 00007ffed933e37f R14: 00007fccffcc39c0 R15: 000000000078c04c
INFO: task syz-executor.3:21192 blocked for more than 140 seconds.
      Not tainted 4.14.177-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D28576 21192   6353 0x80000002
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_timeout+0x946/0xe40 kernel/time/timer.c:1723
 __down_common kernel/locking/semaphore.c:221 [inline]
 __down+0x160/0x290 kernel/locking/semaphore.c:238
 down+0x57/0x80 kernel/locking/semaphore.c:62
 console_lock+0x24/0x70 kernel/printk/printk.c:2216
 con_shutdown+0x3d/0x90 drivers/tty/vt/vt.c:2941
 release_tty+0xb6/0x7a0 drivers/tty/tty_io.c:1501
 tty_release_struct+0x37/0x50 drivers/tty/tty_io.c:1616
 tty_release+0xaa6/0xd60 drivers/tty/tty_io.c:1776
 __fput+0x25f/0x790 fs/file_table.c:210
 task_work_run+0x113/0x190 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x9f2/0x2b00 kernel/exit.c:858
 do_group_exit+0x100/0x310 kernel/exit.c:955
 get_signal+0x385/0x1ca0 kernel/signal.c:2423
 do_signal+0x7c/0x1690 arch/x86/kernel/signal.c:814
 exit_to_usermode_loop+0x159/0x220 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c829
RSP: 002b:00007f2ad5742cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000078bfa8 RCX: 000000000045c829
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000078bfa8
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bfac
R13: 00007ffe6c482cbf R14: 00007f2ad57439c0 R15: 000000000078bfac
INFO: task syz-executor.1:28007 blocked for more than 140 seconds.
      Not tainted 4.14.177-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D28688 28007   6358 0x00000004
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
 fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1497
 __fput+0x25f/0x790 fs/file_table.c:210
 task_work_run+0x113/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1d6/0x220 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x416421
RSP: 002b:00007ffeb03259f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000416421
RDX: 0000001b30b20000 RSI: 0000000000001bb6 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00000000f6c41bb6 R09: 00000000f6c41bba
R10: 00007ffeb0325ae0 R11: 0000000000000293 R12: 000000000078c900
R13: 000000000078c900 R14: ffffffffffffffff R15: 000000000078c04c
INFO: task syz-executor.2:28008 blocked for more than 140 seconds.
      Not tainted 4.14.177-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D28688 28008   6352 0x00000004
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
 fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1497
 __fput+0x25f/0x790 fs/file_table.c:210
 task_work_run+0x113/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1d6/0x220 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x416421
RSP: 002b:00007ffe83822fc0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000416421
RDX: 0000000000000000 RSI: 0000000000001cee RDI: 0000000000000005
RBP: 0000000000000001 R08: 00000000f74bdcee R09: 00000000f74bdcf2
R10: 00007ffe838230b0 R11: 0000000000000293 R12: 000000000078c900
R13: 000000000078c900 R14: ffffffffffffffff R15: 000000000078bf0c
INFO: task syz-executor.4:28049 blocked for more than 140 seconds.
      Not tainted 4.14.177-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D28880 28049   6357 0x00000004
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
 fb_open+0xb7/0x400 drivers/video/fbdev/core/fbmem.c:1468
 chrdev_open+0x1fc/0x540 fs/char_dev.c:423
 do_dentry_open+0x732/0xe90 fs/open.c:777
 vfs_open+0x105/0x220 fs/open.c:888
 do_last fs/namei.c:3428 [inline]
 path_openat+0x8ca/0x3c50 fs/namei.c:3569
 do_filp_open+0x18e/0x250 fs/namei.c:3603
 do_sys_open+0x29d/0x3f0 fs/open.c:1081
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c829
RSP: 002b:00007fccffce3c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000004f71c0 RCX: 000000000045c829
RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000079a R14: 00000000004ca4cf R15: 00007fccffce46d4
INFO: task syz-executor.3:28033 blocked for more than 140 seconds.
      Not tainted 4.14.177-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D28448 28033   6353 0x00000004
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
 fb_open+0xb7/0x400 drivers/video/fbdev/core/fbmem.c:1468
 chrdev_open+0x1fc/0x540 fs/char_dev.c:423
 do_dentry_open+0x732/0xe90 fs/open.c:777
 vfs_open+0x105/0x220 fs/open.c:888
 do_last fs/namei.c:3428 [inline]
 path_openat+0x8ca/0x3c50 fs/namei.c:3569
 do_filp_open+0x18e/0x250 fs/namei.c:3603
 do_sys_open+0x29d/0x3f0 fs/open.c:1081
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c829
RSP: 002b:00007f2ad5763c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000004f71c0 RCX: 000000000045c829
RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000079a R14: 00000000004ca4cf R15: 00007f2ad57646d4
INFO: task syz-executor.3:28052 blocked for more than 140 seconds.
      Not tainted 4.14.177-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D29728 28052   6353 0x00000004
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893
 fb_open+0xb7/0x400 drivers/video/fbdev/core/fbmem.c:1468
 chrdev_open+0x1fc/0x540 fs/char_dev.c:423
 do_dentry_open+0x732/0xe90 fs/open.c:777
 vfs_open+0x105/0x220 fs/open.c:888
 do_last fs/namei.c:3428 [inline]
 path_openat+0x8ca/0x3c50 fs/namei.c:3569
 do_filp_open+0x18e/0x250 fs/namei.c:3603
 do_sys_open+0x29d/0x3f0 fs/open.c:1081
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c829
RSP: 002b:00007f2ad5721c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000004f71c0 RCX: 000000000045c829
RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 000000000078c040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000079a R14: 00000000004ca4cf R15: 00007f2ad57226d4

Showing all locks held in the system:
1 lock held by khungtaskd/1056:
 #0:  (tasklist_lock){.+.+}, at: [<ffffffff81465d43>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548
1 lock held by in:imklog/6034:
 #0:  (&f->f_pos_lock){+.+.}, at: [<ffffffff8191b8f6>] __fdget_pos+0xa6/0xc0 fs/file.c:769
1 lock held by syz-executor.0/9939:
 #0:  (tty_mutex){+.+.}, at: [<ffffffff8339ceec>] tty_release_struct+0x2c/0x50 drivers/tty/tty_io.c:1615
1 lock held by syz-executor.0/9945:
 #0:  (tty_mutex){+.+.}, at: [<ffffffff8339ceec>] tty_release_struct+0x2c/0x50 drivers/tty/tty_io.c:1615
1 lock held by syz-executor.0/9949:
 #0:  (tty_mutex){+.+.}, at: [<ffffffff8339ceec>] tty_release_struct+0x2c/0x50 drivers/tty/tty_io.c:1615
1 lock held by syz-executor.4/17462:
 #0:  (tty_mutex){+.+.}, at: [<ffffffff8339ceec>] tty_release_struct+0x2c/0x50 drivers/tty/tty_io.c:1615
1 lock held by syz-executor.3/21192:
 #0:  (tty_mutex){+.+.}, at: [<ffffffff8339ceec>] tty_release_struct+0x2c/0x50 drivers/tty/tty_io.c:1615
1 lock held by syz-executor.1/28007:
 #0:  (&fb_info->lock){+.+.}, at: [<ffffffff8317279e>] fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1497
1 lock held by syz-executor.2/28008:
 #0:  (&fb_info->lock){+.+.}, at: [<ffffffff8317279e>] fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1497
1 lock held by syz-executor.4/28049:
 #0:  (&fb_info->lock){+.+.}, at: [<ffffffff831730a7>] fb_open+0xb7/0x400 drivers/video/fbdev/core/fbmem.c:1468
1 lock held by syz-executor.3/28033:
 #0:  (&fb_info->lock){+.+.}, at: [<ffffffff831730a7>] fb_open+0xb7/0x400 drivers/video/fbdev/core/fbmem.c:1468
1 lock held by syz-executor.3/28052:
 #0:  (&fb_info->lock){+.+.}, at: [<ffffffff831730a7>] fb_open+0xb7/0x400 drivers/video/fbdev/core/fbmem.c:1468
1 lock held by syz-executor.0/28042:
 #0:  (&fb_info->lock){+.+.}, at: [<ffffffff831730a7>] fb_open+0xb7/0x400 drivers/video/fbdev/core/fbmem.c:1468

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

NMI backtrace for cpu 0
CPU: 0 PID: 1056 Comm: khungtaskd Not tainted 4.14.177-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x13e/0x194 lib/dump_stack.c:58
 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x139/0x17e lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline]
 watchdog+0x5e2/0xb80 kernel/hung_task.c:274
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 28026 Comm: syz-executor.4 Not tainted 4.14.177-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff888062816400 task.stack: ffff888201088000
RIP: 0010:bitfill_aligned drivers/video/fbdev/core/cfbfillrect.c:44 [inline]
RIP: 0010:bitfill_aligned+0x4a/0x190 drivers/video/fbdev/core/cfbfillrect.c:35
RSP: 0018:ffff88820108f318 EFLAGS: 00000246
RAX: 000000000000001e RBX: ffff8880000a0000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff831b17bb RDI: 0000000000000780
RBP: 0000000000000780 R08: 0000000000000780 R09: 0000000000000040
R10: ffffed1014b5f533 R11: ffff8880a5afa99f R12: 0000000000000040
R13: ffffffffffffffff R14: 0000000000000000 R15: 0000000000000000
FS:  00007fccffd05700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000557ea87cb298 CR3: 00000002031bf000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 cfb_fillrect+0x3d5/0x720 drivers/video/fbdev/core/cfbfillrect.c:327
 vga16fb_fillrect+0x61e/0x1880 drivers/video/fbdev/vga16fb.c:951
 bit_clear_margins+0x2a4/0x480 drivers/video/fbdev/core/bitblit.c:232
 fbcon_clear_margins+0x285/0x310 drivers/video/fbdev/core/fbcon.c:1320
 fbcon_switch+0xcdf/0x1780 drivers/video/fbdev/core/fbcon.c:2302
 redraw_screen+0x331/0x770 drivers/tty/vt/vt.c:689
 fbcon_modechanged+0x59d/0x890 drivers/video/fbdev/core/fbcon.c:2949
 fbcon_event_notify+0x11a/0x1746 drivers/video/fbdev/core/fbcon.c:3302
 notifier_call_chain+0x107/0x1a0 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+0x79/0x90 kernel/notifier.c:325
 fb_set_var+0xaad/0xc70 drivers/video/fbdev/core/fbmem.c:1054
 do_fb_ioctl+0x3cc/0x840 drivers/video/fbdev/core/fbmem.c:1127
 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1242
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c829
RSP: 002b:00007fccffd04c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e4740 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: 00007fccffd056d4
Code: 2e 3f fe 85 ed 74 5f e8 45 2e 3f fe 41 8d 3c 2e 44 89 f1 31 d2 49 c7 c5 ff ff ff ff 4c 89 e8 48 d3 e0 48 89 04 24 89 f8 41 f7 f4 <89> d1 49 d3 e5 44 39 e7 49 f7 d5 77 41 e8 14 2e 3f fe 4d 85 ed 

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-14 2020/04/30 17:39 linux-4.14.y 050272a0423e 3698959a .config log report
ci2-linux-4-14 2020/01/11 07:11 linux-4.14.y b0cdffaa546e 4c04afaa .config log report