INFO: task syz-executor.2:14515 can't die for more than 143 seconds. syz-executor.2 D28128 14515 7375 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1447 __fput+0x33e/0x880 fs/file_table.c:280 task_work_run+0xf4/0x1b0 kernel/task_work.c:123 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x2fa/0x360 arch/x86/entry/common.c:165 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x416621 Code: 4c 24 08 e8 11 96 04 00 48 8b 6c 24 58 48 83 c4 60 c3 bb 02 00 00 00 e9 c2 fe ff ff 31 db e9 bb fe ff ff 48 8b 84 24 a0 00 00 <00> 48 89 04 24 48 c7 44 24 08 00 00 00 00 48 8b 44 24 68 48 89 44 RSP: 002b:00007ffdae268890 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000416621 RDX: 0000000000000000 RSI: 0000000000001dae RDI: 0000000000000004 RBP: 0000000000000001 R08: 000000009c417dae R09: 000000009c417db2 R10: 00007ffdae268980 R11: 0000000000000293 R12: 000000000078c900 R13: 000000000078c900 R14: ffffffffffffffff R15: 000000000078bfac INFO: task syz-executor.2:14515 blocked for more than 143 seconds. Not tainted 5.7.0-rc1-next-20200415-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28128 14515 7375 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1447 __fput+0x33e/0x880 fs/file_table.c:280 task_work_run+0xf4/0x1b0 kernel/task_work.c:123 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x2fa/0x360 arch/x86/entry/common.c:165 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x416621 Code: 4c 24 08 e8 11 96 04 00 48 8b 6c 24 58 48 83 c4 60 c3 bb 02 00 00 00 e9 c2 fe ff ff 31 db e9 bb fe ff ff 48 8b 84 24 a0 00 00 <00> 48 89 04 24 48 c7 44 24 08 00 00 00 00 48 8b 44 24 68 48 89 44 RSP: 002b:00007ffdae268890 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000416621 RDX: 0000000000000000 RSI: 0000000000001dae RDI: 0000000000000004 RBP: 0000000000000001 R08: 000000009c417dae R09: 000000009c417db2 R10: 00007ffdae268980 R11: 0000000000000293 R12: 000000000078c900 R13: 000000000078c900 R14: ffffffffffffffff R15: 000000000078bfac INFO: task syz-executor.5:14522 can't die for more than 143 seconds. syz-executor.5 R running task 27696 14522 7709 0x00004006 Call Trace: INFO: task syz-executor.5:14525 can't die for more than 143 seconds. syz-executor.5 D28576 14525 7709 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] do_fb_ioctl+0x1b5/0x6e0 drivers/video/fbdev/core/fbmem.c:1168 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca29 Code: 48 8d 3d 32 36 23 01 e8 f5 22 00 00 eb 98 48 8d 3d 2c 36 23 01 e8 e7 22 00 00 e9 70 ff ff ff 48 8d 3d 3b 36 23 01 e8 d6 22 00 <00> e9 44 ff ff ff 48 8d 3d 22 36 23 01 e8 c5 22 00 00 e9 18 ff ff RSP: 002b:00007f48c2c64c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e9380 RCX: 000000000045ca29 RDX: 0000000000400200 RSI: 0000000000008912 RDI: 000000000000000a RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000415 R14: 00000000004c6d64 R15: 00007f48c2c656d4 INFO: task syz-executor.5:14525 blocked for more than 143 seconds. Not tainted 5.7.0-rc1-next-20200415-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28576 14525 7709 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] do_fb_ioctl+0x1b5/0x6e0 drivers/video/fbdev/core/fbmem.c:1168 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca29 Code: 48 8d 3d 32 36 23 01 e8 f5 22 00 00 eb 98 48 8d 3d 2c 36 23 01 e8 e7 22 00 00 e9 70 ff ff ff 48 8d 3d 3b 36 23 01 e8 d6 22 00 <00> e9 44 ff ff ff 48 8d 3d 22 36 23 01 e8 c5 22 00 00 e9 18 ff ff RSP: 002b:00007f48c2c64c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e9380 RCX: 000000000045ca29 RDX: 0000000000400200 RSI: 0000000000008912 RDI: 000000000000000a RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000415 R14: 00000000004c6d64 R15: 00007f48c2c656d4 INFO: task syz-executor.5:14528 can't die for more than 143 seconds. syz-executor.5 D27472 14528 7709 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4b6/0x12a0 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x1e70/0x27f0 fs/namei.c:3346 do_filp_open+0x192/0x260 fs/namei.c:3373 do_sys_openat2+0x585/0x7d0 fs/open.c:1148 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca29 Code: 48 8d 3d 32 36 23 01 e8 f5 22 00 00 eb 98 48 8d 3d 2c 36 23 01 e8 e7 22 00 00 e9 70 ff ff ff 48 8d 3d 3b 36 23 01 e8 d6 22 00 <00> e9 44 ff ff ff 48 8d 3d 22 36 23 01 e8 c5 22 00 00 e9 18 ff ff RSP: 002b:00007f48c2c43c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f7640 RCX: 000000000045ca29 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007a0 R14: 00000000004ca744 R15: 00007f48c2c446d4 INFO: task syz-executor.5:14528 blocked for more than 143 seconds. Not tainted 5.7.0-rc1-next-20200415-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D27472 14528 7709 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4b6/0x12a0 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x1e70/0x27f0 fs/namei.c:3346 do_filp_open+0x192/0x260 fs/namei.c:3373 do_sys_openat2+0x585/0x7d0 fs/open.c:1148 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca29 Code: 48 8d 3d 32 36 23 01 e8 f5 22 00 00 eb 98 48 8d 3d 2c 36 23 01 e8 e7 22 00 00 e9 70 ff ff ff 48 8d 3d 3b 36 23 01 e8 d6 22 00 <00> e9 44 ff ff ff 48 8d 3d 22 36 23 01 e8 c5 22 00 00 e9 18 ff ff RSP: 002b:00007f48c2c43c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f7640 RCX: 000000000045ca29 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007a0 R14: 00000000004ca744 R15: 00007f48c2c446d4 INFO: task syz-executor.3:14524 can't die for more than 143 seconds. syz-executor.3 D28400 14524 7427 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4b6/0x12a0 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x1e70/0x27f0 fs/namei.c:3346 do_filp_open+0x192/0x260 fs/namei.c:3373 do_sys_openat2+0x585/0x7d0 fs/open.c:1148 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca29 Code: 48 8d 3d 32 36 23 01 e8 f5 22 00 00 eb 98 48 8d 3d 2c 36 23 01 e8 e7 22 00 00 e9 70 ff ff ff 48 8d 3d 3b 36 23 01 e8 d6 22 00 <00> e9 44 ff ff ff 48 8d 3d 22 36 23 01 e8 c5 22 00 00 e9 18 ff ff RSP: 002b:00007f58f6a02c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f7640 RCX: 000000000045ca29 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007a0 R14: 00000000004ca744 R15: 00007f58f6a036d4 INFO: task syz-executor.3:14524 blocked for more than 143 seconds. Not tainted 5.7.0-rc1-next-20200415-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28400 14524 7427 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4b6/0x12a0 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x1e70/0x27f0 fs/namei.c:3346 do_filp_open+0x192/0x260 fs/namei.c:3373 do_sys_openat2+0x585/0x7d0 fs/open.c:1148 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca29 Code: 48 8d 3d 32 36 23 01 e8 f5 22 00 00 eb 98 48 8d 3d 2c 36 23 01 e8 e7 22 00 00 e9 70 ff ff ff 48 8d 3d 3b 36 23 01 e8 d6 22 00 <00> e9 44 ff ff ff 48 8d 3d 22 36 23 01 e8 c5 22 00 00 e9 18 ff ff RSP: 002b:00007f58f6a02c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f7640 RCX: 000000000045ca29 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007a0 R14: 00000000004ca744 R15: 00007f58f6a036d4 INFO: task syz-executor.3:14526 can't die for more than 143 seconds. syz-executor.3 D28400 14526 7427 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4b6/0x12a0 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x1e70/0x27f0 fs/namei.c:3346 do_filp_open+0x192/0x260 fs/namei.c:3373 do_sys_openat2+0x585/0x7d0 fs/open.c:1148 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca29 Code: 48 8d 3d 32 36 23 01 e8 f5 22 00 00 eb 98 48 8d 3d 2c 36 23 01 e8 e7 22 00 00 e9 70 ff ff ff 48 8d 3d 3b 36 23 01 e8 d6 22 00 <00> e9 44 ff ff ff 48 8d 3d 22 36 23 01 e8 c5 22 00 00 e9 18 ff ff RSP: 002b:00007f58f69e1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f7640 RCX: 000000000045ca29 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007a0 R14: 00000000004ca744 R15: 00007f58f69e26d4 INFO: task syz-executor.3:14526 blocked for more than 143 seconds. Not tainted 5.7.0-rc1-next-20200415-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28400 14526 7427 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4b6/0x12a0 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x1e70/0x27f0 fs/namei.c:3346 do_filp_open+0x192/0x260 fs/namei.c:3373 do_sys_openat2+0x585/0x7d0 fs/open.c:1148 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca29 Code: 48 8d 3d 32 36 23 01 e8 f5 22 00 00 eb 98 48 8d 3d 2c 36 23 01 e8 e7 22 00 00 e9 70 ff ff ff 48 8d 3d 3b 36 23 01 e8 d6 22 00 <00> e9 44 ff ff ff 48 8d 3d 22 36 23 01 e8 c5 22 00 00 e9 18 ff ff RSP: 002b:00007f58f69e1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f7640 RCX: 000000000045ca29 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007a0 R14: 00000000004ca744 R15: 00007f58f69e26d4 Showing all locks held in the system: 1 lock held by khungtaskd/1167: #0: ffffffff899befc0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5754 1 lock held by in:imklog/6802: #0: ffff8880a46cc0f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 4 locks held by rs:main Q:Reg/6803: 2 locks held by agetty/7031: #0: ffff88809fcd5098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900012dc2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x220/0x1b30 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.2/14515: #0: ffff8880a2c3c078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a2c3c078 (&fb_info->lock){+.+.}-{3:3}, at: fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1447 2 locks held by syz-executor.5/14522: 1 lock held by syz-executor.5/14525: #0: ffff8880a2c3c078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a2c3c078 (&fb_info->lock){+.+.}-{3:3}, at: do_fb_ioctl+0x1b5/0x6e0 drivers/video/fbdev/core/fbmem.c:1168 1 lock held by syz-executor.5/14528: #0: ffff8880a2c3c078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a2c3c078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by syz-executor.3/14524: #0: ffff8880a2c3c078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a2c3c078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by syz-executor.3/14526: #0: ffff8880a2c3c078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a2c3c078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1167 Comm: khungtaskd Not tainted 5.7.0-rc1-next-20200415-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+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:249 [inline] watchdog+0xde3/0x14e0 kernel/hung_task.c:333 kthread+0x388/0x470 kernel/kthread.c:268 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 6803 Comm: rs:main Q:Reg Not tainted 5.7.0-rc1-next-20200415-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:759 [inline] RIP: 0010:lock_acquire+0x24d/0x8f0 kernel/locking/lockdep.c:4937 Code: 05 06 00 00 83 ab cc 08 00 00 01 0f 85 46 04 00 00 48 c7 c0 e0 c4 94 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 <0f> 85 c6 05 00 00 48 83 3d 35 42 3b 08 00 0f 84 65 04 00 00 48 8b RSP: 0018:ffffc9000a0a79c8 EFLAGS: 00000046 RAX: 1ffffffff132989c RBX: ffff8880901463c0 RCX: 29a4ca71a0a98111 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff888090146c8c RBP: 0000000000000000 R08: 0000000000000001 R09: fffffbfff186274e R10: ffffffff8c313a6f R11: fffffbfff186274d R12: 0000000000000000 R13: ffff88808aa1b388 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fb62e216700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6ebc4f9000 CR3: 00000000a913d000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: down_write+0x8d/0x150 kernel/locking/rwsem.c:1531 inode_lock include/linux/fs.h:797 [inline] ext4_buffered_write_iter+0xb3/0x450 fs/ext4/file.c:264 ext4_file_write_iter+0x1ec/0x13f0 fs/ext4/file.c:642 call_write_iter include/linux/fs.h:1907 [inline] new_sync_write+0x4a2/0x700 fs/read_write.c:484 __vfs_write+0xc9/0x100 fs/read_write.c:497 vfs_write+0x268/0x5d0 fs/read_write.c:559 ksys_write+0x12d/0x250 fs/read_write.c:612 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x7fb630c5a1cd Code: c2 20 00 00 75 10 b8 01 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ae fc ff ff 48 89 04 24 b8 01 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 f7 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007fb62e215580 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fb6240286a0 RCX: 00007fb630c5a1cd RDX: 0000000000001000 RSI: 00007fb6240286a0 RDI: 000000000000000a RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007fb624028420 R13: 00007fb62e2155a0 R14: 0000000000000051 R15: 0000000000001000