INFO: task hung in lock_fb_info
6 views
Skip to first unread message
syzbot
Jan 11, 2020, 6:48:11 AM1/11/20
to syzkaller...@googlegroups.com
Hello,
syzbot found the following crash on:
HEAD commit: cb1f9a16 Linux 4.19.94
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15bc69e1e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=9d03b07719ed036e
dashboard link: https://syzkaller.appspot.com/bug?extid=4316d53a51a3e21d8adb
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
Unfortunately, I don't have any reproducer for this crash yet.
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+4316d5...@syzkaller.appspotmail.com
INFO: task syz-executor.1:13292 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 D29544 13292 8063 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
lock_fb_info+0x1f/0x80 drivers/video/fbdev/core/fbmem.c:81
do_fb_ioctl+0x22b/0xab0 drivers/video/fbdev/core/fbmem.c:1212
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:00007f7dc13b6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045af49
RDX: 0000000000000000 RSI: 000000004020565b RDI: 0000000000000004
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7dc13b76d4
R13: 00000000004d21c8 R14: 00000000004df1c8 R15: 00000000ffffffff
INFO: task syz-executor.1:13301 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 D27864 13301 8063 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: 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:00007f7dc1374c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045af49
RDX: 0000000000000000 RSI: 00000000200001c0 RDI: ffffffffffffff9c
RBP: 000000000075c118 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7dc13756d4
R13: 00000000004c88ce R14: 00000000004e0e30 R15: 00000000ffffffff
INFO: task syz-executor.4:13288 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 D28240 13288 8075 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: 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:00007f325d0e5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045af49
RDX: 0000000000000000 RSI: 00000000200001c0 RDI: ffffffffffffff9c
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f325d0e66d4
R13: 00000000004c88ce R14: 00000000004e0e30 R15: 00000000ffffffff
Showing all locks held in the system:
1 lock held by khungtaskd/1079:
#0: 0000000009d48362 (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/7895:
#0: 00000000a785ad0e (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110
fs/file.c:767
2 locks held by getty/8017:
#0: 0000000068c5b562 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000dbc278a0 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8018:
#0: 00000000f73428af (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 000000007eee27ed (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8019:
#0: 000000003fd48963 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000c972303c (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8020:
#0: 00000000d7d2b226 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000a182b625 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8021:
#0: 000000000992722e (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000265d0be7 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8022:
#0: 0000000075a534c4 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 000000006f1e39fd (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8023:
#0: 000000003a6c8418 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 0000000023787150 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
3 locks held by syz-executor.1/13286:
1 lock held by syz-executor.1/13292:
#0: 000000005a4be6fa (&fb_info->lock){+.+.}, at: lock_fb_info+0x1f/0x80
drivers/video/fbdev/core/fbmem.c:81
1 lock held by syz-executor.1/13301:
#0: 000000005a4be6fa (&fb_info->lock){+.+.}, at: fb_open+0xd7/0x450
drivers/video/fbdev/core/fbmem.c:1457
1 lock held by syz-executor.4/13288:
#0: 000000005a4be6fa (&fb_info->lock){+.+.}, at: fb_open+0xd7/0x450
drivers/video/fbdev/core/fbmem.c:1457
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 1079 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 1089 Comm: khugepaged Not tainted 4.19.94-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:23 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:67 [inline]
RIP: 0010:write_comp_data+0x9/0x70 kernel/kcov.c:122
Code: 12 00 00 8b 80 d4 12 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89
34 d1 48 89 11 5d c3 0f 1f 00 65 4c 8b 04 25 40 ee 01 00 <65> 8b 05 c0 d7
96 7e a9 00 01 1f 00 75 51 41 8b 80 d0 12 00 00 83
RSP: 0018:ffff8880a7ce7b18 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffffea0001032940 RCX: ffffffff81999c5b
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007
RBP: ffff8880a7ce7b20 R08: ffff8880a7cb4440 R09: fffff9400020652f
R10: fffff9400020652e R11: ffffea0001032973 R12: ffffea0001032940
R13: ffffea0001032948 R14: 0000000000000000 R15: dead000000000100
FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 0000000008e6d000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
compound_head include/linux/page-flags.h:144 [inline]
PageMlocked include/linux/page-flags.h:354 [inline]
page_remove_rmap mm/rmap.c:1316 [inline]
page_remove_rmap+0x13b/0x12c0 mm/rmap.c:1297
__collapse_huge_page_copy mm/khugepaged.c:676 [inline]
collapse_huge_page+0x2384/0x3d10 mm/khugepaged.c:1063
khugepaged_scan_pmd mm/khugepaged.c:1219 [inline]
khugepaged_scan_mm_slot mm/khugepaged.c:1757 [inline]
khugepaged_do_scan mm/khugepaged.c:1838 [inline]
khugepaged+0x2e9a/0x3f20 mm/khugepaged.c:1883
kthread+0x354/0x420 kernel/kthread.c:246
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot found the following crash on:
HEAD commit: cb1f9a16 Linux 4.19.94
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15bc69e1e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=9d03b07719ed036e
dashboard link: https://syzkaller.appspot.com/bug?extid=4316d53a51a3e21d8adb
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
Unfortunately, I don't have any reproducer for this crash yet.
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+4316d5...@syzkaller.appspotmail.com
INFO: task syz-executor.1:13292 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 D29544 13292 8063 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
lock_fb_info+0x1f/0x80 drivers/video/fbdev/core/fbmem.c:81
do_fb_ioctl+0x22b/0xab0 drivers/video/fbdev/core/fbmem.c:1212
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:00007f7dc13b6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045af49
RDX: 0000000000000000 RSI: 000000004020565b RDI: 0000000000000004
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7dc13b76d4
R13: 00000000004d21c8 R14: 00000000004df1c8 R15: 00000000ffffffff
INFO: task syz-executor.1:13301 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 D27864 13301 8063 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: 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:00007f7dc1374c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045af49
RDX: 0000000000000000 RSI: 00000000200001c0 RDI: ffffffffffffff9c
RBP: 000000000075c118 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7dc13756d4
R13: 00000000004c88ce R14: 00000000004e0e30 R15: 00000000ffffffff
INFO: task syz-executor.4:13288 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 D28240 13288 8075 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: 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:00007f325d0e5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045af49
RDX: 0000000000000000 RSI: 00000000200001c0 RDI: ffffffffffffff9c
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f325d0e66d4
R13: 00000000004c88ce R14: 00000000004e0e30 R15: 00000000ffffffff
Showing all locks held in the system:
1 lock held by khungtaskd/1079:
#0: 0000000009d48362 (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/7895:
#0: 00000000a785ad0e (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110
fs/file.c:767
2 locks held by getty/8017:
#0: 0000000068c5b562 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000dbc278a0 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8018:
#0: 00000000f73428af (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 000000007eee27ed (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8019:
#0: 000000003fd48963 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000c972303c (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8020:
#0: 00000000d7d2b226 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000a182b625 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8021:
#0: 000000000992722e (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000265d0be7 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8022:
#0: 0000000075a534c4 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 000000006f1e39fd (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8023:
#0: 000000003a6c8418 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 0000000023787150 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
3 locks held by syz-executor.1/13286:
1 lock held by syz-executor.1/13292:
#0: 000000005a4be6fa (&fb_info->lock){+.+.}, at: lock_fb_info+0x1f/0x80
drivers/video/fbdev/core/fbmem.c:81
1 lock held by syz-executor.1/13301:
#0: 000000005a4be6fa (&fb_info->lock){+.+.}, at: fb_open+0xd7/0x450
drivers/video/fbdev/core/fbmem.c:1457
1 lock held by syz-executor.4/13288:
#0: 000000005a4be6fa (&fb_info->lock){+.+.}, at: fb_open+0xd7/0x450
drivers/video/fbdev/core/fbmem.c:1457
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 1079 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 1089 Comm: khugepaged Not tainted 4.19.94-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:23 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:67 [inline]
RIP: 0010:write_comp_data+0x9/0x70 kernel/kcov.c:122
Code: 12 00 00 8b 80 d4 12 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89
34 d1 48 89 11 5d c3 0f 1f 00 65 4c 8b 04 25 40 ee 01 00 <65> 8b 05 c0 d7
96 7e a9 00 01 1f 00 75 51 41 8b 80 d0 12 00 00 83
RSP: 0018:ffff8880a7ce7b18 EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffffea0001032940 RCX: ffffffff81999c5b
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007
RBP: ffff8880a7ce7b20 R08: ffff8880a7cb4440 R09: fffff9400020652f
R10: fffff9400020652e R11: ffffea0001032973 R12: ffffea0001032940
R13: ffffea0001032948 R14: 0000000000000000 R15: dead000000000100
FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 0000000008e6d000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
compound_head include/linux/page-flags.h:144 [inline]
PageMlocked include/linux/page-flags.h:354 [inline]
page_remove_rmap mm/rmap.c:1316 [inline]
page_remove_rmap+0x13b/0x12c0 mm/rmap.c:1297
__collapse_huge_page_copy mm/khugepaged.c:676 [inline]
collapse_huge_page+0x2384/0x3d10 mm/khugepaged.c:1063
khugepaged_scan_pmd mm/khugepaged.c:1219 [inline]
khugepaged_scan_mm_slot mm/khugepaged.c:1757 [inline]
khugepaged_do_scan mm/khugepaged.c:1838 [inline]
khugepaged+0x2e9a/0x3f20 mm/khugepaged.c:1883
kthread+0x354/0x420 kernel/kthread.c:246
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot
Aug 28, 2020, 12:48:10 PM8/28/20
to syzkaller...@googlegroups.com
Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.
Crashes did not happen for a while, no reproducer and no activity.
Reply all
Reply to author
Forward
0 new messages