[ OK ] Started Getty on tty4. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty1. [ 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 '10.128.1.46' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 55.543688][ T6805] input: syz0 as /devices/virtual/input/input5 [ 55.557507][ T6805] ================================================================== [ 55.565749][ T6805] BUG: KASAN: use-after-free in __mutex_lock+0x1033/0x13c0 [ 55.572949][ T6805] Read of size 8 at addr ffff8880a972d158 by task syz-executor198/6805 [ 55.581213][ T6805] [ 55.583546][ T6805] CPU: 1 PID: 6805 Comm: syz-executor198 Not tainted 5.7.0-rc6-next-20200522-syzkaller #0 [ 55.593429][ T6805] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 55.603483][ T6805] Call Trace: [ 55.606770][ T6805] dump_stack+0x18f/0x20d [ 55.611303][ T6805] ? __mutex_lock+0x1033/0x13c0 [ 55.616173][ T6805] ? __mutex_lock+0x1033/0x13c0 [ 55.621026][ T6805] print_address_description.constprop.0.cold+0xd3/0x413 [ 55.628024][ T6805] ? cdev_device_del+0x69/0x80 [ 55.632764][ T6805] ? evdev_disconnect+0x3d/0xb0 [ 55.637590][ T6805] ? __input_unregister_device+0x1b0/0x430 [ 55.643373][ T6805] ? input_unregister_device+0xb4/0xf0 [ 55.648821][ T6805] ? uinput_destroy_device+0x1e2/0x240 [ 55.654263][ T6805] ? vprintk_func+0x97/0x1a6 [ 55.658834][ T6805] ? __mutex_lock+0x1033/0x13c0 [ 55.663799][ T6805] kasan_report.cold+0x1f/0x37 [ 55.668553][ T6805] ? __mutex_lock+0x1033/0x13c0 [ 55.673386][ T6805] __mutex_lock+0x1033/0x13c0 [ 55.678049][ T6805] ? evdev_cleanup+0x21/0x190 [ 55.682708][ T6805] ? print_usage_bug+0x240/0x240 [ 55.687625][ T6805] ? trace_hardirqs_off+0x50/0x220 [ 55.692797][ T6805] ? mutex_trylock+0x2c0/0x2c0 [ 55.697537][ T6805] ? mark_held_locks+0x9f/0xe0 [ 55.702276][ T6805] ? kfree+0x1eb/0x2b0 [ 55.706330][ T6805] ? lockdep_hardirqs_on_prepare+0x3a2/0x590 [ 55.712287][ T6805] ? kfree_const+0x51/0x60 [ 55.716685][ T6805] ? evdev_cleanup+0x21/0x190 [ 55.721338][ T6805] evdev_cleanup+0x21/0x190 [ 55.725820][ T6805] evdev_disconnect+0x45/0xb0 [ 55.730477][ T6805] __input_unregister_device+0x1b0/0x430 [ 55.736100][ T6805] input_unregister_device+0xb4/0xf0 [ 55.741363][ T6805] uinput_destroy_device+0x1e2/0x240 [ 55.746628][ T6805] ? uinput_destroy_device+0x240/0x240 [ 55.752071][ T6805] uinput_release+0x37/0x50 [ 55.756549][ T6805] __fput+0x33e/0x880 [ 55.760510][ T6805] task_work_run+0xf4/0x1b0 [ 55.765005][ T6805] do_exit+0xb5e/0x2e10 [ 55.769146][ T6805] ? fsnotify_first_mark+0x191/0x200 [ 55.774425][ T6805] ? debug_smp_processor_id+0x2f/0x185 [ 55.779931][ T6805] ? mm_update_next_owner+0x7a0/0x7a0 [ 55.785333][ T6805] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 55.791313][ T6805] ? vfs_write+0x161/0x5d0 [ 55.795719][ T6805] do_group_exit+0x125/0x340 [ 55.800303][ T6805] __x64_sys_exit_group+0x3a/0x50 [ 55.805312][ T6805] do_syscall_64+0xf6/0x7d0 [ 55.809928][ T6805] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 55.815875][ T6805] RIP: 0033:0x43fa18 [ 55.819770][ T6805] Code: Bad RIP value. [ 55.823818][ T6805] RSP: 002b:00007ffe16b5b238 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 55.832215][ T6805] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043fa18 [ 55.840309][ T6805] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 55.848270][ T6805] RBP: 00000000004bf268 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 55.856235][ T6805] R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000000001 [ 55.864186][ T6805] R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000 [ 55.873053][ T6805] [ 55.875381][ T6805] Allocated by task 6805: [ 55.879698][ T6805] save_stack+0x1b/0x40 [ 55.883829][ T6805] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 55.889436][ T6805] kmem_cache_alloc_trace+0x153/0x7d0 [ 55.894796][ T6805] evdev_connect+0x80/0x4d0 [ 55.899273][ T6805] input_attach_handler+0x194/0x200 [ 55.904571][ T6805] input_register_device.cold+0xf5/0x246 [ 55.910399][ T6805] uinput_ioctl_handler.isra.0+0x1210/0x1d80 [ 55.916375][ T6805] ksys_ioctl+0x11a/0x180 [ 55.920769][ T6805] __x64_sys_ioctl+0x6f/0xb0 [ 55.925335][ T6805] do_syscall_64+0xf6/0x7d0 [ 55.929863][ T6805] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 55.935738][ T6805] [ 55.938062][ T6805] Freed by task 6805: [ 55.942022][ T6805] save_stack+0x1b/0x40 [ 55.946166][ T6805] __kasan_slab_free+0xf7/0x140 [ 55.950989][ T6805] kfree+0x109/0x2b0 [ 55.954873][ T6805] device_release+0x71/0x200 [ 55.959464][ T6805] kobject_put+0x1c8/0x2f0 [ 55.963857][ T6805] cdev_device_del+0x69/0x80 [ 55.968437][ T6805] evdev_disconnect+0x3d/0xb0 [ 55.973090][ T6805] __input_unregister_device+0x1b0/0x430 [ 55.978711][ T6805] input_unregister_device+0xb4/0xf0 [ 55.984007][ T6805] uinput_destroy_device+0x1e2/0x240 [ 55.989279][ T6805] uinput_release+0x37/0x50 [ 55.994043][ T6805] __fput+0x33e/0x880 [ 55.998221][ T6805] task_work_run+0xf4/0x1b0 [ 56.002721][ T6805] do_exit+0xb5e/0x2e10 [ 56.006870][ T6805] do_group_exit+0x125/0x340 [ 56.011458][ T6805] __x64_sys_exit_group+0x3a/0x50 [ 56.016475][ T6805] do_syscall_64+0xf6/0x7d0 [ 56.020960][ T6805] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 56.026834][ T6805] [ 56.029146][ T6805] The buggy address belongs to the object at ffff8880a972d000 [ 56.029146][ T6805] which belongs to the cache kmalloc-2k of size 2048 [ 56.043785][ T6805] The buggy address is located 344 bytes inside of [ 56.043785][ T6805] 2048-byte region [ffff8880a972d000, ffff8880a972d800) [ 56.057212][ T6805] The buggy address belongs to the page: [ 56.062821][ T6805] page:ffffea0002a5cb40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 56.071909][ T6805] flags: 0xfffe0000000200(slab) [ 56.076746][ T6805] raw: 00fffe0000000200 ffffea00026b3788 ffff8880aa001950 ffff8880aa000e00 [ 56.085305][ T6805] raw: 0000000000000000 ffff8880a972d000 0000000100000001 0000000000000000 [ 56.094141][ T6805] page dumped because: kasan: bad access detected [ 56.100613][ T6805] [ 56.102918][ T6805] Memory state around the buggy address: [ 56.108523][ T6805] ffff8880a972d000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 56.116656][ T6805] ffff8880a972d080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 56.124692][ T6805] >ffff8880a972d100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 56.132723][ T6805] ^ [ 56.139642][ T6805] ffff8880a972d180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 56.148017][ T6805] ffff8880a972d200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 56.156054][ T6805] ================================================================== [ 56.164091][ T6805] Disabling lock debugging due to kernel taint [ 56.171553][ T6805] Kernel panic - not syncing: panic_on_warn set ... [ 56.178163][ T6805] CPU: 1 PID: 6805 Comm: syz-executor198 Tainted: G B 5.7.0-rc6-next-20200522-syzkaller #0 [ 56.189428][ T6805] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 56.199477][ T6805] Call Trace: [ 56.202766][ T6805] dump_stack+0x18f/0x20d [ 56.207101][ T6805] ? __mutex_lock+0xf50/0x13c0 [ 56.211840][ T6805] panic+0x2e3/0x75c [ 56.215733][ T6805] ? __warn_printk+0xf3/0xf3 [ 56.220297][ T6805] ? preempt_schedule_common+0x5e/0xc0 [ 56.225727][ T6805] ? __mutex_lock+0x1033/0x13c0 [ 56.230562][ T6805] ? __mutex_lock+0x1033/0x13c0 [ 56.235389][ T6805] ? preempt_schedule_thunk+0x16/0x18 [ 56.240733][ T6805] ? trace_hardirqs_on+0x55/0x230 [ 56.245745][ T6805] ? __mutex_lock+0x1033/0x13c0 [ 56.250574][ T6805] ? __mutex_lock+0x1033/0x13c0 [ 56.255407][ T6805] end_report+0x4d/0x53 [ 56.259535][ T6805] kasan_report.cold+0xd/0x37 [ 56.264187][ T6805] ? __mutex_lock+0x1033/0x13c0 [ 56.269354][ T6805] __mutex_lock+0x1033/0x13c0 [ 56.274005][ T6805] ? evdev_cleanup+0x21/0x190 [ 56.278845][ T6805] ? print_usage_bug+0x240/0x240 [ 56.283782][ T6805] ? trace_hardirqs_off+0x50/0x220 [ 56.288900][ T6805] ? mutex_trylock+0x2c0/0x2c0 [ 56.293644][ T6805] ? mark_held_locks+0x9f/0xe0 [ 56.298381][ T6805] ? kfree+0x1eb/0x2b0 [ 56.303725][ T6805] ? lockdep_hardirqs_on_prepare+0x3a2/0x590 [ 56.309696][ T6805] ? kfree_const+0x51/0x60 [ 56.314183][ T6805] ? evdev_cleanup+0x21/0x190 [ 56.318829][ T6805] evdev_cleanup+0x21/0x190 [ 56.323318][ T6805] evdev_disconnect+0x45/0xb0 [ 56.327970][ T6805] __input_unregister_device+0x1b0/0x430 [ 56.333587][ T6805] input_unregister_device+0xb4/0xf0 [ 56.338857][ T6805] uinput_destroy_device+0x1e2/0x240 [ 56.344231][ T6805] ? uinput_destroy_device+0x240/0x240 [ 56.349660][ T6805] uinput_release+0x37/0x50 [ 56.354149][ T6805] __fput+0x33e/0x880 [ 56.358120][ T6805] task_work_run+0xf4/0x1b0 [ 56.362719][ T6805] do_exit+0xb5e/0x2e10 [ 56.366884][ T6805] ? fsnotify_first_mark+0x191/0x200 [ 56.372248][ T6805] ? debug_smp_processor_id+0x2f/0x185 [ 56.377697][ T6805] ? mm_update_next_owner+0x7a0/0x7a0 [ 56.383109][ T6805] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 56.389084][ T6805] ? vfs_write+0x161/0x5d0 [ 56.393597][ T6805] do_group_exit+0x125/0x340 [ 56.398169][ T6805] __x64_sys_exit_group+0x3a/0x50 [ 56.403315][ T6805] do_syscall_64+0xf6/0x7d0 [ 56.407804][ T6805] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 56.413721][ T6805] RIP: 0033:0x43fa18 [ 56.417908][ T6805] Code: Bad RIP value. [ 56.421967][ T6805] RSP: 002b:00007ffe16b5b238 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 56.430354][ T6805] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043fa18 [ 56.438310][ T6805] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 56.446279][ T6805] RBP: 00000000004bf268 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 56.454223][ T6805] R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000000001 [ 56.462166][ T6805] R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000 [ 56.471677][ T6805] Kernel Offset: disabled [ 56.476010][ T6805] Rebooting in 86400 seconds..