[ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty3. [ OK ] Started Getty on tty2. [ OK ] Reached target Login Prompts. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.44' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 59.768362][ T6791] input: syz1 as /devices/virtual/input/input5 [ 59.782940][ T6791] ================================================================== [ 59.791198][ T6791] BUG: KASAN: use-after-free in __mutex_lock+0x1033/0x13c0 [ 59.798403][ T6791] Read of size 8 at addr ffff8880a019f158 by task syz-executor054/6791 [ 59.806659][ T6791] [ 59.809003][ T6791] CPU: 0 PID: 6791 Comm: syz-executor054 Not tainted 5.7.0-rc6-next-20200522-syzkaller #0 [ 59.818924][ T6791] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 59.829455][ T6791] Call Trace: [ 59.832936][ T6791] dump_stack+0x18f/0x20d [ 59.838299][ T6791] ? __mutex_lock+0x1033/0x13c0 [ 59.843618][ T6791] ? __mutex_lock+0x1033/0x13c0 [ 59.848597][ T6791] print_address_description.constprop.0.cold+0xd3/0x413 [ 59.856045][ T6791] ? cdev_device_del+0x69/0x80 [ 59.860817][ T6791] ? evdev_disconnect+0x3d/0xb0 [ 59.865754][ T6791] ? __input_unregister_device+0x1b0/0x430 [ 59.871541][ T6791] ? input_unregister_device+0xb4/0xf0 [ 59.877102][ T6791] ? uinput_destroy_device+0x1e2/0x240 [ 59.882566][ T6791] ? vprintk_func+0x97/0x1a6 [ 59.887269][ T6791] ? __mutex_lock+0x1033/0x13c0 [ 59.892113][ T6791] kasan_report.cold+0x1f/0x37 [ 59.896860][ T6791] ? __mutex_lock+0x1033/0x13c0 [ 59.902146][ T6791] __mutex_lock+0x1033/0x13c0 [ 59.906815][ T6791] ? evdev_cleanup+0x21/0x190 [ 59.911751][ T6791] ? print_usage_bug+0x240/0x240 [ 59.916686][ T6791] ? trace_hardirqs_off+0x50/0x220 [ 59.921778][ T6791] ? mutex_trylock+0x2c0/0x2c0 [ 59.926540][ T6791] ? mark_held_locks+0x9f/0xe0 [ 59.931299][ T6791] ? kfree+0x1eb/0x2b0 [ 59.935603][ T6791] ? lockdep_hardirqs_on_prepare+0x3a2/0x590 [ 59.942467][ T6791] ? kfree_const+0x51/0x60 [ 59.946902][ T6791] ? evdev_cleanup+0x21/0x190 [ 59.955069][ T6791] evdev_cleanup+0x21/0x190 [ 59.959654][ T6791] evdev_disconnect+0x45/0xb0 [ 59.964448][ T6791] __input_unregister_device+0x1b0/0x430 [ 59.970606][ T6791] input_unregister_device+0xb4/0xf0 [ 59.976019][ T6791] uinput_destroy_device+0x1e2/0x240 [ 59.981502][ T6791] ? uinput_destroy_device+0x240/0x240 [ 59.987005][ T6791] uinput_release+0x37/0x50 [ 59.991522][ T6791] __fput+0x33e/0x880 [ 59.995527][ T6791] task_work_run+0xf4/0x1b0 [ 60.000897][ T6791] do_exit+0xb5e/0x2e10 [ 60.005216][ T6791] ? fsnotify_first_mark+0x191/0x200 [ 60.010682][ T6791] ? uinput_dev_upload_effect+0x1e0/0x1e0 [ 60.016382][ T6791] ? mm_update_next_owner+0x7a0/0x7a0 [ 60.021849][ T6791] ? vfs_write+0x161/0x5d0 [ 60.026302][ T6791] do_group_exit+0x125/0x340 [ 60.030925][ T6791] __x64_sys_exit_group+0x3a/0x50 [ 60.036150][ T6791] do_syscall_64+0xf6/0x7d0 [ 60.040685][ T6791] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 60.046565][ T6791] RIP: 0033:0x43f9e8 [ 60.050447][ T6791] Code: Bad RIP value. [ 60.054509][ T6791] RSP: 002b:00007ffd043eeff8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 60.062906][ T6791] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043f9e8 [ 60.070860][ T6791] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 60.078829][ T6791] RBP: 00000000004bf228 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 60.086797][ T6791] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 60.094766][ T6791] R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000 [ 60.103339][ T6791] [ 60.105658][ T6791] Allocated by task 6791: [ 60.109982][ T6791] save_stack+0x1b/0x40 [ 60.114127][ T6791] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 60.119744][ T6791] kmem_cache_alloc_trace+0x153/0x7d0 [ 60.125128][ T6791] evdev_connect+0x80/0x4d0 [ 60.130328][ T6791] input_attach_handler+0x194/0x200 [ 60.135508][ T6791] input_register_device.cold+0xf5/0x246 [ 60.141121][ T6791] uinput_ioctl_handler.isra.0+0x1210/0x1d80 [ 60.147079][ T6791] ksys_ioctl+0x11a/0x180 [ 60.151408][ T6791] __x64_sys_ioctl+0x6f/0xb0 [ 60.155988][ T6791] do_syscall_64+0xf6/0x7d0 [ 60.160654][ T6791] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 60.166641][ T6791] [ 60.168960][ T6791] Freed by task 6791: [ 60.173034][ T6791] save_stack+0x1b/0x40 [ 60.177316][ T6791] __kasan_slab_free+0xf7/0x140 [ 60.182264][ T6791] kfree+0x109/0x2b0 [ 60.186324][ T6791] device_release+0x71/0x200 [ 60.190917][ T6791] kobject_put+0x1c8/0x2f0 [ 60.195329][ T6791] cdev_device_del+0x69/0x80 [ 60.199919][ T6791] evdev_disconnect+0x3d/0xb0 [ 60.204754][ T6791] __input_unregister_device+0x1b0/0x430 [ 60.211502][ T6791] input_unregister_device+0xb4/0xf0 [ 60.216910][ T6791] uinput_destroy_device+0x1e2/0x240 [ 60.222475][ T6791] uinput_release+0x37/0x50 [ 60.226960][ T6791] __fput+0x33e/0x880 [ 60.232349][ T6791] task_work_run+0xf4/0x1b0 [ 60.237139][ T6791] do_exit+0xb5e/0x2e10 [ 60.241339][ T6791] do_group_exit+0x125/0x340 [ 60.245911][ T6791] __x64_sys_exit_group+0x3a/0x50 [ 60.254898][ T6791] do_syscall_64+0xf6/0x7d0 [ 60.259931][ T6791] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 60.267132][ T6791] [ 60.269455][ T6791] The buggy address belongs to the object at ffff8880a019f000 [ 60.269455][ T6791] which belongs to the cache kmalloc-2k of size 2048 [ 60.283513][ T6791] The buggy address is located 344 bytes inside of [ 60.283513][ T6791] 2048-byte region [ffff8880a019f000, ffff8880a019f800) [ 60.296878][ T6791] The buggy address belongs to the page: [ 60.302499][ T6791] page:ffffea00028067c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 [ 60.311826][ T6791] flags: 0xfffe0000000200(slab) [ 60.317671][ T6791] raw: 00fffe0000000200 ffffea00029b4348 ffff8880aa001950 ffff8880aa000e00 [ 60.326487][ T6791] raw: 0000000000000000 ffff8880a019f000 0000000100000001 0000000000000000 [ 60.336349][ T6791] page dumped because: kasan: bad access detected [ 60.343009][ T6791] [ 60.345481][ T6791] Memory state around the buggy address: [ 60.351104][ T6791] ffff8880a019f000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.359342][ T6791] ffff8880a019f080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.369500][ T6791] >ffff8880a019f100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.377786][ T6791] ^ [ 60.385184][ T6791] ffff8880a019f180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.394163][ T6791] ffff8880a019f200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 60.402980][ T6791] ================================================================== [ 60.412006][ T6791] Disabling lock debugging due to kernel taint [ 60.418588][ T6791] Kernel panic - not syncing: panic_on_warn set ... [ 60.425201][ T6791] CPU: 0 PID: 6791 Comm: syz-executor054 Tainted: G B 5.7.0-rc6-next-20200522-syzkaller #0 [ 60.437778][ T6791] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.447926][ T6791] Call Trace: [ 60.451331][ T6791] dump_stack+0x18f/0x20d [ 60.456380][ T6791] ? __mutex_lock+0xf50/0x13c0 [ 60.461258][ T6791] panic+0x2e3/0x75c [ 60.465354][ T6791] ? __warn_printk+0xf3/0xf3 [ 60.470588][ T6791] ? preempt_schedule_common+0x5e/0xc0 [ 60.477036][ T6791] ? __mutex_lock+0x1033/0x13c0 [ 60.482044][ T6791] ? __mutex_lock+0x1033/0x13c0 [ 60.487386][ T6791] ? preempt_schedule_thunk+0x16/0x18 [ 60.492934][ T6791] ? trace_hardirqs_on+0x55/0x230 [ 60.498192][ T6791] ? __mutex_lock+0x1033/0x13c0 [ 60.503325][ T6791] ? __mutex_lock+0x1033/0x13c0 [ 60.508390][ T6791] end_report+0x4d/0x53 [ 60.512546][ T6791] kasan_report.cold+0xd/0x37 [ 60.517396][ T6791] ? __mutex_lock+0x1033/0x13c0 [ 60.522489][ T6791] __mutex_lock+0x1033/0x13c0 [ 60.527159][ T6791] ? evdev_cleanup+0x21/0x190 [ 60.531964][ T6791] ? print_usage_bug+0x240/0x240 [ 60.538376][ T6791] ? trace_hardirqs_off+0x50/0x220 [ 60.545327][ T6791] ? mutex_trylock+0x2c0/0x2c0 [ 60.550432][ T6791] ? mark_held_locks+0x9f/0xe0 [ 60.555367][ T6791] ? kfree+0x1eb/0x2b0 [ 60.561681][ T6791] ? lockdep_hardirqs_on_prepare+0x3a2/0x590 [ 60.569668][ T6791] ? kfree_const+0x51/0x60 [ 60.574232][ T6791] ? evdev_cleanup+0x21/0x190 [ 60.579036][ T6791] evdev_cleanup+0x21/0x190 [ 60.583553][ T6791] evdev_disconnect+0x45/0xb0 [ 60.588672][ T6791] __input_unregister_device+0x1b0/0x430 [ 60.594312][ T6791] input_unregister_device+0xb4/0xf0 [ 60.599605][ T6791] uinput_destroy_device+0x1e2/0x240 [ 60.605208][ T6791] ? uinput_destroy_device+0x240/0x240 [ 60.610673][ T6791] uinput_release+0x37/0x50 [ 60.615322][ T6791] __fput+0x33e/0x880 [ 60.619308][ T6791] task_work_run+0xf4/0x1b0 [ 60.623975][ T6791] do_exit+0xb5e/0x2e10 [ 60.628279][ T6791] ? fsnotify_first_mark+0x191/0x200 [ 60.634461][ T6791] ? uinput_dev_upload_effect+0x1e0/0x1e0 [ 60.640361][ T6791] ? mm_update_next_owner+0x7a0/0x7a0 [ 60.646158][ T6791] ? vfs_write+0x161/0x5d0 [ 60.651691][ T6791] do_group_exit+0x125/0x340 [ 60.657734][ T6791] __x64_sys_exit_group+0x3a/0x50 [ 60.662884][ T6791] do_syscall_64+0xf6/0x7d0 [ 60.667556][ T6791] entry_SYSCALL_64_after_hwframe+0x49/0xb3 [ 60.673440][ T6791] RIP: 0033:0x43f9e8 [ 60.679718][ T6791] Code: Bad RIP value. [ 60.685594][ T6791] RSP: 002b:00007ffd043eeff8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 60.694866][ T6791] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043f9e8 [ 60.703263][ T6791] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 60.711373][ T6791] RBP: 00000000004bf228 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 60.720241][ T6791] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 60.731289][ T6791] R13: 00000000006d1180 R14: 0000000000000000 R15: 0000000000000000 [ 60.740909][ T6791] Kernel Offset: disabled [ 60.745735][ T6791] Rebooting in 86400 seconds..