[ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Getty on tty1. [ OK ] Started Serial Getty on ttyS0. [ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.28' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 57.079599][ T6830] input: syz1 as /devices/virtual/input/input5 [ 57.095931][ T6830] ================================================================== [ 57.104154][ T6830] BUG: KASAN: use-after-free in __mutex_lock+0x1033/0x13c0 [ 57.111357][ T6830] Read of size 8 at addr ffff8880a7395158 by task syz-executor466/6830 [ 57.119588][ T6830] [ 57.121921][ T6830] CPU: 0 PID: 6830 Comm: syz-executor466 Not tainted 5.7.0-rc6-next-20200522-syzkaller #0 [ 57.131801][ T6830] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 57.141854][ T6830] Call Trace: [ 57.145158][ T6830] dump_stack+0x18f/0x20d [ 57.149466][ T6830] ? __mutex_lock+0x1033/0x13c0 [ 57.154310][ T6830] ? __mutex_lock+0x1033/0x13c0 [ 57.159153][ T6830] print_address_description.constprop.0.cold+0xd3/0x413 [ 57.166526][ T6830] ? cdev_device_del+0x69/0x80 [ 57.171411][ T6830] ? evdev_disconnect+0x3d/0xb0 [ 57.176266][ T6830] ? __input_unregister_device+0x1b0/0x430 [ 57.182145][ T6830] ? input_unregister_device+0xb4/0xf0 [ 57.187604][ T6830] ? uinput_destroy_device+0x1e2/0x240 [ 57.193046][ T6830] ? vprintk_func+0x97/0x1a6 [ 57.197616][ T6830] ? __mutex_lock+0x1033/0x13c0 [ 57.202483][ T6830] kasan_report.cold+0x1f/0x37 [ 57.207228][ T6830] ? __mutex_lock+0x1033/0x13c0 [ 57.212404][ T6830] __mutex_lock+0x1033/0x13c0 [ 57.217063][ T6830] ? evdev_cleanup+0x21/0x190 [ 57.221717][ T6830] ? print_usage_bug+0x240/0x240 [ 57.226631][ T6830] ? trace_hardirqs_off+0x50/0x220 [ 57.231736][ T6830] ? mutex_trylock+0x2c0/0x2c0 [ 57.236597][ T6830] ? mark_held_locks+0x9f/0xe0 [ 57.241349][ T6830] ? kfree+0x1eb/0x2b0 [ 57.245406][ T6830] ? lockdep_hardirqs_on_prepare+0x3a2/0x590 [ 57.251390][ T6830] ? kfree_const+0x51/0x60 [ 57.255798][ T6830] ? evdev_cleanup+0x21/0x190 [ 57.260467][ T6830] evdev_cleanup+0x21/0x190 [ 57.264976][ T6830] evdev_disconnect+0x45/0xb0 [ 57.269633][ T6830] __input_unregister_device+0x1b0/0x430 [ 57.275371][ T6830] input_unregister_device+0xb4/0xf0 [ 57.280637][ T6830] uinput_destroy_device+0x1e2/0x240 [ 57.285905][ T6830] ? uinput_destroy_device+0x240/0x240 [ 57.291423][ T6830] uinput_release+0x37/0x50 [ 57.295929][ T6830] __fput+0x33e/0x880 [ 57.299901][ T6830] task_work_run+0xf4/0x1b0 [ 57.304392][ T6830] do_exit+0xb5e/0x2e10 [ 57.308527][ T6830] ? fsnotify_first_mark+0x191/0x200 [ 57.313810][ T6830] ? uinput_dev_upload_effect+0x1e0/0x1e0 [ 57.319522][ T6830] ? mm_update_next_owner+0x7a0/0x7a0 [ 57.324872][ T6830] ? vfs_write+0x161/0x5d0 [ 57.329299][ T6830] do_group_exit+0x125/0x340 [ 57.333885][ T6830] __x64_sys_exit_group+0x3a/0x50 [ 57.338898][ T6830] do_syscall_64+0xf6/0x7d0 [ 57.343384][ T6830] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 57.349277][ T6830] RIP: 0033:0x43f9e8 [ 57.353170][ T6830] Code: Bad RIP value. [ 57.357224][ T6830] RSP: 002b:00007ffcc2ed4ff8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 57.366081][ T6830] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043f9e8 [ 57.374052][ T6830] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 57.382038][ T6830] RBP: 00000000004bf228 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 57.389997][ T6830] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 57.397961][ T6830] R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000 [ 57.405918][ T6830] [ 57.408233][ T6830] Allocated by task 6830: [ 57.412545][ T6830] save_stack+0x1b/0x40 [ 57.416691][ T6830] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 57.422386][ T6830] kmem_cache_alloc_trace+0x153/0x7d0 [ 57.427744][ T6830] evdev_connect+0x80/0x4d0 [ 57.432222][ T6830] input_attach_handler+0x194/0x200 [ 57.437409][ T6830] input_register_device.cold+0xf5/0x246 [ 57.443035][ T6830] uinput_ioctl_handler.isra.0+0x1210/0x1d80 [ 57.448998][ T6830] ksys_ioctl+0x11a/0x180 [ 57.453318][ T6830] __x64_sys_ioctl+0x6f/0xb0 [ 57.457884][ T6830] do_syscall_64+0xf6/0x7d0 [ 57.462363][ T6830] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 57.468225][ T6830] [ 57.470527][ T6830] Freed by task 6830: [ 57.474839][ T6830] save_stack+0x1b/0x40 [ 57.478970][ T6830] __kasan_slab_free+0xf7/0x140 [ 57.483812][ T6830] kfree+0x109/0x2b0 [ 57.487682][ T6830] device_release+0x71/0x200 [ 57.492401][ T6830] kobject_put+0x1c8/0x2f0 [ 57.496816][ T6830] cdev_device_del+0x69/0x80 [ 57.501404][ T6830] evdev_disconnect+0x3d/0xb0 [ 57.506234][ T6830] __input_unregister_device+0x1b0/0x430 [ 57.511862][ T6830] input_unregister_device+0xb4/0xf0 [ 57.517150][ T6830] uinput_destroy_device+0x1e2/0x240 [ 57.522428][ T6830] uinput_release+0x37/0x50 [ 57.526907][ T6830] __fput+0x33e/0x880 [ 57.530911][ T6830] task_work_run+0xf4/0x1b0 [ 57.535425][ T6830] do_exit+0xb5e/0x2e10 [ 57.539742][ T6830] do_group_exit+0x125/0x340 [ 57.544313][ T6830] __x64_sys_exit_group+0x3a/0x50 [ 57.549772][ T6830] do_syscall_64+0xf6/0x7d0 [ 57.554387][ T6830] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 57.560356][ T6830] [ 57.562666][ T6830] The buggy address belongs to the object at ffff8880a7395000 [ 57.562666][ T6830] which belongs to the cache kmalloc-2k of size 2048 [ 57.576792][ T6830] The buggy address is located 344 bytes inside of [ 57.576792][ T6830] 2048-byte region [ffff8880a7395000, ffff8880a7395800) [ 57.590353][ T6830] The buggy address belongs to the page: [ 57.596147][ T6830] page:ffffea00029ce540 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 57.605350][ T6830] flags: 0xfffe0000000200(slab) [ 57.610195][ T6830] raw: 00fffe0000000200 ffffea00024bbcc8 ffff8880aa001950 ffff8880aa000e00 [ 57.618770][ T6830] raw: 0000000000000000 ffff8880a7395000 0000000100000001 0000000000000000 [ 57.627334][ T6830] page dumped because: kasan: bad access detected [ 57.633716][ T6830] [ 57.636032][ T6830] Memory state around the buggy address: [ 57.641639][ T6830] ffff8880a7395000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 57.651599][ T6830] ffff8880a7395080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 57.659634][ T6830] >ffff8880a7395100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 57.667678][ T6830] ^ [ 57.674595][ T6830] ffff8880a7395180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 57.682642][ T6830] ffff8880a7395200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 57.690731][ T6830] ================================================================== [ 57.699581][ T6830] Disabling lock debugging due to kernel taint [ 57.720812][ T6830] Kernel panic - not syncing: panic_on_warn set ... [ 57.727431][ T6830] CPU: 0 PID: 6830 Comm: syz-executor466 Tainted: G B 5.7.0-rc6-next-20200522-syzkaller #0 [ 57.738705][ T6830] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 57.749712][ T6830] Call Trace: [ 57.753473][ T6830] dump_stack+0x18f/0x20d [ 57.757836][ T6830] ? __mutex_lock+0xf50/0x13c0 [ 57.762597][ T6830] panic+0x2e3/0x75c [ 57.766591][ T6830] ? __warn_printk+0xf3/0xf3 [ 57.771179][ T6830] ? preempt_schedule_common+0x5e/0xc0 [ 57.776632][ T6830] ? __mutex_lock+0x1033/0x13c0 [ 57.781475][ T6830] ? __mutex_lock+0x1033/0x13c0 [ 57.786424][ T6830] ? preempt_schedule_thunk+0x16/0x18 [ 57.791792][ T6830] ? trace_hardirqs_on+0x55/0x230 [ 57.796806][ T6830] ? __mutex_lock+0x1033/0x13c0 [ 57.801727][ T6830] ? __mutex_lock+0x1033/0x13c0 [ 57.806571][ T6830] end_report+0x4d/0x53 [ 57.810712][ T6830] kasan_report.cold+0xd/0x37 [ 57.815381][ T6830] ? __mutex_lock+0x1033/0x13c0 [ 57.820204][ T6830] __mutex_lock+0x1033/0x13c0 [ 57.825380][ T6830] ? evdev_cleanup+0x21/0x190 [ 57.830047][ T6830] ? print_usage_bug+0x240/0x240 [ 57.834961][ T6830] ? trace_hardirqs_off+0x50/0x220 [ 57.840047][ T6830] ? mutex_trylock+0x2c0/0x2c0 [ 57.844797][ T6830] ? mark_held_locks+0x9f/0xe0 [ 57.849552][ T6830] ? kfree+0x1eb/0x2b0 [ 57.853605][ T6830] ? lockdep_hardirqs_on_prepare+0x3a2/0x590 [ 57.859557][ T6830] ? kfree_const+0x51/0x60 [ 57.863973][ T6830] ? evdev_cleanup+0x21/0x190 [ 57.868718][ T6830] evdev_cleanup+0x21/0x190 [ 57.873211][ T6830] evdev_disconnect+0x45/0xb0 [ 57.877949][ T6830] __input_unregister_device+0x1b0/0x430 [ 57.883557][ T6830] input_unregister_device+0xb4/0xf0 [ 57.888914][ T6830] uinput_destroy_device+0x1e2/0x240 [ 57.894206][ T6830] ? uinput_destroy_device+0x240/0x240 [ 57.900072][ T6830] uinput_release+0x37/0x50 [ 57.904561][ T6830] __fput+0x33e/0x880 [ 57.908516][ T6830] task_work_run+0xf4/0x1b0 [ 57.912996][ T6830] do_exit+0xb5e/0x2e10 [ 57.917127][ T6830] ? fsnotify_first_mark+0x191/0x200 [ 57.922386][ T6830] ? uinput_dev_upload_effect+0x1e0/0x1e0 [ 57.928078][ T6830] ? mm_update_next_owner+0x7a0/0x7a0 [ 57.933427][ T6830] ? vfs_write+0x161/0x5d0 [ 57.937836][ T6830] do_group_exit+0x125/0x340 [ 57.942423][ T6830] __x64_sys_exit_group+0x3a/0x50 [ 57.947421][ T6830] do_syscall_64+0xf6/0x7d0 [ 57.951899][ T6830] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 57.957762][ T6830] RIP: 0033:0x43f9e8 [ 57.961643][ T6830] Code: Bad RIP value. [ 57.965678][ T6830] RSP: 002b:00007ffcc2ed4ff8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 57.974074][ T6830] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043f9e8 [ 57.982038][ T6830] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 57.990688][ T6830] RBP: 00000000004bf228 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 57.998645][ T6830] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 58.006598][ T6830] R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000 [ 58.015970][ T6830] Kernel Offset: disabled [ 58.020293][ T6830] Rebooting in 86400 seconds..