syzbot


INFO: task hung in tty_release_struct

Status: auto-closed as invalid on 2020/10/13 06:21
Subsystems: serial
[Documentation on labels]
First crash: 1381d, last: 1374d
Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in tty_release_struct 1 490d 490d 0/1 auto-obsoleted due to no activity on 2023/04/15 07:55
linux-4.14 INFO: task hung in tty_release_struct 2 1450d 1560d 0/1 auto-closed as invalid on 2020/08/28 17:40
upstream INFO: task hung in tty_release_struct (6) serial 1 96d 96d 0/26 auto-obsoleted due to no activity on 2024/04/13 21:30
upstream INFO: task hung in tty_release_struct (2) serial 7 808d 944d 0/26 closed as invalid on 2022/02/07 19:19
upstream INFO: task hung in tty_release_struct (3) serial 3 750d 794d 0/26 auto-closed as invalid on 2022/06/29 20:46
android-414 INFO: task hung in tty_release_struct 7 1955d 1834d 0/1 auto-closed as invalid on 2019/06/10 11:00
upstream INFO: task hung in tty_release_struct (5) serial 1 285d 285d 0/26 auto-obsoleted due to no activity on 2023/10/07 22:46
upstream INFO: task hung in tty_release_struct (4) serial 2 569d 607d 0/26 auto-obsoleted due to no activity on 2023/01/03 08:49

Sample crash report:
INFO: task syz-executor.0:12502 blocked for more than 143 seconds.
      Not tainted 5.8.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D28384 12502   6913 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3453 [inline]
 __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178
 schedule+0xd0/0x2a0 kernel/sched/core.c:4253
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4312
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103
 tty_release_struct+0xa9/0xe0 drivers/tty/tty_io.c:1624
 tty_release+0xc67/0xf60 drivers/tty/tty_io.c:1785
 __fput+0x33c/0x880 fs/file_table.c:281
 task_work_run+0xdd/0x190 kernel/task_work.c:135
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:216 [inline]
 __prepare_exit_to_usermode+0x1e9/0x1f0 arch/x86/entry/common.c:246
 do_syscall_64+0x6c/0xe0 arch/x86/entry/common.c:368
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x416721
Code: Bad RIP value.
RSP: 002b:00007ffd39dbf190 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000007 RCX: 0000000000416721
RDX: 0000000000000000 RSI: ffffffff87e7391b RDI: 0000000000000006
RBP: 0000000000000001 R08: ffffffff812a6f80 R09: 000000008f953987
R10: 00007ffd39dbf280 R11: 0000000000000293 R12: 000000000078c900
R13: 000000000078c900 R14: ffffffffffffffff R15: 000000000078bfac
INFO: task syz-executor.0:12503 blocked for more than 143 seconds.
      Not tainted 5.8.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D27984 12503   6913 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:3453 [inline]
 __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178
 schedule+0xd0/0x2a0 kernel/sched/core.c:4253
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4312
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103
 tty_open_by_driver drivers/tty/tty_io.c:1947 [inline]
 tty_open+0x51d/0xf60 drivers/tty/tty_io.c:2031
 chrdev_open+0x266/0x770 fs/char_dev.c:414
 do_dentry_open+0x501/0x1290 fs/open.c:828
 do_open fs/namei.c:3243 [inline]
 path_openat+0x1bb9/0x2750 fs/namei.c:3360
 do_filp_open+0x17e/0x3c0 fs/namei.c:3387
 do_sys_openat2+0x16f/0x3b0 fs/open.c:1179
 do_sys_open fs/open.c:1195 [inline]
 ksys_open include/linux/syscalls.h:1388 [inline]
 __do_sys_open fs/open.c:1201 [inline]
 __se_sys_open fs/open.c:1199 [inline]
 __x64_sys_open+0x119/0x1c0 fs/open.c:1199
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x416921
Code: Bad RIP value.
RSP: 002b:00007fbcd9763ba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 000000000050b160 RCX: 0000000000416921
RDX: 0000000000000000 RSI: 0004000000101041 RDI: 00007fbcd9763bd0
RBP: 000000000078bf00 R08: 0000000000000000 R09: 000000000000000a
R10: 0000000000000064 R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000c6b R14: 00000000004cec7f R15: 00007fbcd97646d4
INFO: task syz-executor.2:12530 blocked for more than 143 seconds.
      Not tainted 5.8.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D28384 12530   7103 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:3453 [inline]
 __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178
 schedule+0xd0/0x2a0 kernel/sched/core.c:4253
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4312
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103
 tty_release_struct+0xa9/0xe0 drivers/tty/tty_io.c:1624
 tty_release+0xc67/0xf60 drivers/tty/tty_io.c:1785
 __fput+0x33c/0x880 fs/file_table.c:281
 task_work_run+0xdd/0x190 kernel/task_work.c:135
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:216 [inline]
 __prepare_exit_to_usermode+0x1e9/0x1f0 arch/x86/entry/common.c:246
 do_syscall_64+0x6c/0xe0 arch/x86/entry/common.c:368
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x416721
Code: Bad RIP value.
RSP: 002b:00007ffc929adb10 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000008 RCX: 0000000000416721
RDX: 0000000000000000 RSI: 0000000000001c83 RDI: 0000000000000007
RBP: 0000000000000001 R08: 000000009100bc83 R09: 000000009100bc87
R10: 00007ffc929adc00 R11: 0000000000000293 R12: 000000000078c900
R13: 000000000078c900 R14: ffffffffffffffff R15: 000000000078bfac
INFO: task syz-executor.1:12538 blocked for more than 143 seconds.
      Not tainted 5.8.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D27736 12538   7057 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3453 [inline]
 __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178
 schedule+0xd0/0x2a0 kernel/sched/core.c:4253
 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1873
 __down_common kernel/locking/semaphore.c:220 [inline]
 __down+0x183/0x2a0 kernel/locking/semaphore.c:237
 down+0x57/0x80 kernel/locking/semaphore.c:61
 console_lock+0x25/0x80 kernel/printk/printk.c:2309
 con_install+0x8c/0x5c0 drivers/tty/vt/vt.c:3252
 tty_driver_install_tty drivers/tty/tty_io.c:1228 [inline]
 tty_init_dev.part.0+0x9e/0x610 drivers/tty/tty_io.c:1341
 tty_init_dev include/linux/err.h:36 [inline]
 tty_open_by_driver drivers/tty/tty_io.c:1983 [inline]
 tty_open+0xb2e/0xf60 drivers/tty/tty_io.c:2031
 chrdev_open+0x266/0x770 fs/char_dev.c:414
 do_dentry_open+0x501/0x1290 fs/open.c:828
 do_open fs/namei.c:3243 [inline]
 path_openat+0x1bb9/0x2750 fs/namei.c:3360
 do_filp_open+0x17e/0x3c0 fs/namei.c:3387
 do_sys_openat2+0x16f/0x3b0 fs/open.c:1179
 do_sys_open fs/open.c:1195 [inline]
 ksys_open include/linux/syscalls.h:1388 [inline]
 __do_sys_open fs/open.c:1201 [inline]
 __se_sys_open fs/open.c:1199 [inline]
 __x64_sys_open+0x119/0x1c0 fs/open.c:1199
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x416921
Code: Bad RIP value.
RSP: 002b:00007f206540f7a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 000000000050ade0 RCX: 0000000000416921
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007f206540f7d0
RBP: 000000000078bf00 R08: 0000000000000000 R09: 000000000000000e
R10: 0000000000000064 R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000c5d R14: 00000000004ceb70 R15: 00007f20654106d4
INFO: task syz-executor.1:12539 blocked for more than 143 seconds.
      Not tainted 5.8.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D26104 12539   7057 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:3453 [inline]
 __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178
 schedule+0xd0/0x2a0 kernel/sched/core.c:4253
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4312
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103
 tty_open_by_driver drivers/tty/tty_io.c:1947 [inline]
 tty_open+0x51d/0xf60 drivers/tty/tty_io.c:2031
 chrdev_open+0x266/0x770 fs/char_dev.c:414
 do_dentry_open+0x501/0x1290 fs/open.c:828
 do_open fs/namei.c:3243 [inline]
 path_openat+0x1bb9/0x2750 fs/namei.c:3360
 do_filp_open+0x17e/0x3c0 fs/namei.c:3387
 do_sys_openat2+0x16f/0x3b0 fs/open.c:1179
 do_sys_open fs/open.c:1195 [inline]
 ksys_open include/linux/syscalls.h:1388 [inline]
 __do_sys_open fs/open.c:1201 [inline]
 __se_sys_open fs/open.c:1199 [inline]
 __x64_sys_open+0x119/0x1c0 fs/open.c:1199
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x416921
Code: Bad RIP value.
RSP: 002b:00007f20653ee7a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 000000000050ade0 RCX: 0000000000416921
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007f20653ee7d0
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 000000000000000e
R10: 0000000000000064 R11: 0000000000000293 R12: 00000000ffffffff
R13: 0000000000000c5d R14: 00000000004ceb70 R15: 00007f20653ef6d4
INFO: task syz-executor.3:12575 blocked for more than 143 seconds.
      Not tainted 5.8.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D26944 12575   7264 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3453 [inline]
 __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178
 schedule+0xd0/0x2a0 kernel/sched/core.c:4253
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4312
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103
 ptmx_open drivers/tty/pty.c:844 [inline]
 ptmx_open+0x103/0x360 drivers/tty/pty.c:811
 chrdev_open+0x266/0x770 fs/char_dev.c:414
 do_dentry_open+0x501/0x1290 fs/open.c:828
 do_open fs/namei.c:3243 [inline]
 path_openat+0x1bb9/0x2750 fs/namei.c:3360
 do_filp_open+0x17e/0x3c0 fs/namei.c:3387
 do_sys_openat2+0x16f/0x3b0 fs/open.c:1179
 do_sys_open fs/open.c:1195 [inline]
 __do_sys_openat fs/open.c:1209 [inline]
 __se_sys_openat fs/open.c:1204 [inline]
 __x64_sys_openat+0x13f/0x1f0 fs/open.c:1204
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cb29
Code: Bad RIP value.
RSP: 002b:00007f0f8ccfac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000004f8f20 RCX: 000000000045cb29
RDX: 0000000000000000 RSI: 0000000020000140 RDI: ffffffffffffff9c
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000007e2 R14: 00000000004cacca R15: 00007f0f8ccfb6d4
INFO: task syz-executor.3:12577 blocked for more than 143 seconds.
      Not tainted 5.8.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D28392 12577   7264 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:3453 [inline]
 __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178
 schedule+0xd0/0x2a0 kernel/sched/core.c:4253
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4312
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103
 ptmx_open drivers/tty/pty.c:844 [inline]
 ptmx_open+0x103/0x360 drivers/tty/pty.c:811
 chrdev_open+0x266/0x770 fs/char_dev.c:414
 do_dentry_open+0x501/0x1290 fs/open.c:828
 do_open fs/namei.c:3243 [inline]
 path_openat+0x1bb9/0x2750 fs/namei.c:3360
 do_filp_open+0x17e/0x3c0 fs/namei.c:3387
 do_sys_openat2+0x16f/0x3b0 fs/open.c:1179
 do_sys_open fs/open.c:1195 [inline]
 __do_sys_openat fs/open.c:1209 [inline]
 __se_sys_openat fs/open.c:1204 [inline]
 __x64_sys_openat+0x13f/0x1f0 fs/open.c:1204
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cb29
Code: Bad RIP value.
RSP: 002b:00007f0f8ccd9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000004f8f20 RCX: 000000000045cb29
RDX: 0000000000000000 RSI: 0000000020000140 RDI: ffffffffffffff9c
RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000007e2 R14: 00000000004cacca R15: 00007f0f8ccda6d4
INFO: task syz-executor.3:12576 blocked for more than 143 seconds.
      Not tainted 5.8.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D28376 12576  12575 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3453 [inline]
 __schedule+0x8e1/0x1eb0 kernel/sched/core.c:4178
 schedule+0xd0/0x2a0 kernel/sched/core.c:4253
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4312
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103
 tty_open_by_driver drivers/tty/tty_io.c:1947 [inline]
 tty_open+0x51d/0xf60 drivers/tty/tty_io.c:2031
 chrdev_open+0x266/0x770 fs/char_dev.c:414
 do_dentry_open+0x501/0x1290 fs/open.c:828
 do_open fs/namei.c:3243 [inline]
 path_openat+0x1bb9/0x2750 fs/namei.c:3360
 do_filp_open+0x17e/0x3c0 fs/namei.c:3387
 do_sys_openat2+0x16f/0x3b0 fs/open.c:1179
 do_sys_open fs/open.c:1195 [inline]
 __do_sys_openat fs/open.c:1209 [inline]
 __se_sys_openat fs/open.c:1204 [inline]
 __x64_sys_openat+0x13f/0x1f0 fs/open.c:1204
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cb29
Code: Bad RIP value.
RSP: 002b:00007f0f8ccfac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000004f9f20 RCX: 000000000045cb29
RDX: 0000000000000002 RSI: 0000000020000200 RDI: ffffffffffffff9c
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000822 R14: 00000000004cb193 R15: 00007f0f8ccfb6d4

Showing all locks held in the system:
1 lock held by khungtaskd/1142:
 #0: ffffffff89bc1180 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5779
1 lock held by in:imklog/6582:
 #0: ffff8880a92d9af0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826
1 lock held by syz-executor.3/8482:
 #0: ffffffff8a1762c8 (tty_mutex){+.+.}-{3:3}, at: tty_release_struct+0xa9/0xe0 drivers/tty/tty_io.c:1624
2 locks held by syz-executor.4/12501:
1 lock held by syz-executor.0/12502:
 #0: ffffffff8a1762c8 (tty_mutex){+.+.}-{3:3}, at: tty_release_struct+0xa9/0xe0 drivers/tty/tty_io.c:1624
1 lock held by syz-executor.0/12503:
 #0: ffffffff8a1762c8 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:1947 [inline]
 #0: ffffffff8a1762c8 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x51d/0xf60 drivers/tty/tty_io.c:2031
1 lock held by syz-executor.2/12530:
 #0: ffffffff8a1762c8 (tty_mutex){+.+.}-{3:3}, at: tty_release_struct+0xa9/0xe0 drivers/tty/tty_io.c:1624
2 locks held by syz-executor.1/12538:
 #0: ffffffff8a1762c8 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:1947 [inline]
 #0: ffffffff8a1762c8 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x51d/0xf60 drivers/tty/tty_io.c:2031
 #1: ffff8880a6ce01c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: tty_lock+0xbd/0x120 drivers/tty/tty_mutex.c:19
1 lock held by syz-executor.1/12539:
 #0: ffffffff8a1762c8 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:1947 [inline]
 #0: ffffffff8a1762c8 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x51d/0xf60 drivers/tty/tty_io.c:2031
1 lock held by syz-executor.3/12575:
 #0: ffffffff8a1762c8 (tty_mutex){+.+.}-{3:3}, at: ptmx_open drivers/tty/pty.c:844 [inline]
 #0: ffffffff8a1762c8 (tty_mutex){+.+.}-{3:3}, at: ptmx_open+0x103/0x360 drivers/tty/pty.c:811
1 lock held by syz-executor.3/12577:
 #0: ffffffff8a1762c8 (tty_mutex){+.+.}-{3:3}, at: ptmx_open drivers/tty/pty.c:844 [inline]
 #0: ffffffff8a1762c8 (tty_mutex){+.+.}-{3:3}, at: ptmx_open+0x103/0x360 drivers/tty/pty.c:811
1 lock held by syz-executor.3/12576:
 #0: ffffffff8a1762c8 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:1947 [inline]
 #0: ffffffff8a1762c8 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x51d/0xf60 drivers/tty/tty_io.c:2031

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

NMI backtrace for cpu 0
CPU: 0 PID: 1142 Comm: khungtaskd Not tainted 5.8.0-rc3-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+0x18f/0x20d lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline]
 watchdog+0xd7d/0x1000 kernel/hung_task.c:295
 kthread+0x3b5/0x4a0 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 12501 Comm: syz-executor.4 Not tainted 5.8.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__sanitizer_cov_trace_pc+0x45/0x60 kernel/kcov.c:202
Code: f6 c4 01 74 35 8b 82 04 14 00 00 85 c0 74 2b 8b 82 e0 13 00 00 83 f8 02 75 20 48 8b 8a e8 13 00 00 8b 92 e4 13 00 00 48 8b 01 <48> 83 c0 01 48 39 c2 76 07 48 89 34 c1 48 89 01 c3 66 2e 0f 1f 84
RSP: 0018:ffffc90001bb74e8 EFLAGS: 00000246
RAX: 000000000003ffff RBX: 0000000000000000 RCX: ffffc900124cd000
RDX: 0000000000040000 RSI: ffffffff83c20172 RDI: 0000000000000004
RBP: 0000000000000040 R08: 0000000000000a00 R09: 0000000000000040
R10: 0000000000000a00 R11: 0000000000000000 R12: 0000000000000a00
R13: ffff8880000a0000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f0dcdf24700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f2bb5f09f8 CR3: 0000000093993000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 bitfill_aligned drivers/video/fbdev/core/cfbfillrect.c:55 [inline]
 bitfill_aligned+0xc2/0x200 drivers/video/fbdev/core/cfbfillrect.c:35
 cfb_fillrect+0x40b/0x7b0 drivers/video/fbdev/core/cfbfillrect.c:327
 vga16fb_fillrect+0x683/0x193b drivers/video/fbdev/vga16fb.c:951
 bit_clear_margins+0x2d5/0x4a0 drivers/video/fbdev/core/bitblit.c:232
 fbcon_clear_margins+0x1d5/0x230 drivers/video/fbdev/core/fbcon.c:1381
 fbcon_switch+0xb6e/0x16c0 drivers/video/fbdev/core/fbcon.c:2363
 redraw_screen+0x2ae/0x770 drivers/tty/vt/vt.c:1015
 fbcon_modechanged+0x575/0x710 drivers/video/fbdev/core/fbcon.c:3001
 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3048
 fb_set_var+0xae8/0xd60 drivers/video/fbdev/core/fbmem.c:1056
 do_fb_ioctl+0x33f/0x6c0 drivers/video/fbdev/core/fbmem.c:1109
 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1185
 vfs_ioctl fs/ioctl.c:48 [inline]
 ksys_ioctl+0x11a/0x180 fs/ioctl.c:753
 __do_sys_ioctl fs/ioctl.c:762 [inline]
 __se_sys_ioctl fs/ioctl.c:760 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cb29
Code: Bad RIP value.
RSP: 002b:00007f0dcdf23c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e55e0 RCX: 000000000045cb29
RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000002fd R14: 00000000004c58a5 R15: 00007f0dcdf246d4

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/07/08 19:01 upstream 7cc2a8ea1048 51095195 .config console log report ci-upstream-kasan-gce-selinux-root
2020/07/15 06:16 linux-next 5fb3d6042387 609fb517 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.