[ 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 '10.128.10.13' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 42.668424] ================================================================== [ 42.675927] BUG: KASAN: use-after-free in vgem_gem_dumb_create+0x22c/0x240 [ 42.682937] Read of size 8 at addr ffff8880aa10b880 by task syz-executor767/10900 [ 42.690538] [ 42.692151] CPU: 1 PID: 10900 Comm: syz-executor767 Not tainted 4.19.184-syzkaller #0 [ 42.700104] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.709441] Call Trace: [ 42.712018] dump_stack+0x1fc/0x2ef [ 42.715641] print_address_description.cold+0x54/0x219 [ 42.720909] kasan_report_error.cold+0x8a/0x1b9 [ 42.725574] ? vgem_gem_dumb_create+0x22c/0x240 [ 42.730232] __asan_report_load8_noabort+0x88/0x90 [ 42.735148] ? drm_gem_object_put_unlocked+0xc0/0x180 [ 42.740331] ? vgem_gem_dumb_create+0x22c/0x240 [ 42.744999] vgem_gem_dumb_create+0x22c/0x240 [ 42.749525] drm_mode_create_dumb+0x27c/0x300 [ 42.754014] drm_ioctl_kernel+0x208/0x2a0 [ 42.758185] ? drm_mode_create_dumb+0x300/0x300 [ 42.762836] ? drm_ioctl_permit+0x210/0x210 [ 42.767147] ? __might_fault+0x192/0x1d0 [ 42.771190] drm_ioctl+0x507/0x9c0 [ 42.774717] ? drm_mode_create_dumb+0x300/0x300 [ 42.779373] ? drm_getstats+0x20/0x20 [ 42.783165] ? signal_setup_done+0xdd/0x460 [ 42.787471] ? get_signal+0x1f70/0x1f70 [ 42.791432] ? futex_exit_release+0x220/0x220 [ 42.795913] ? drm_getstats+0x20/0x20 [ 42.799697] do_vfs_ioctl+0xcdb/0x12e0 [ 42.803573] ? lock_downgrade+0x720/0x720 [ 42.807707] ? check_preemption_disabled+0x41/0x280 [ 42.812707] ? ioctl_preallocate+0x200/0x200 [ 42.817101] ? __fget+0x356/0x510 [ 42.820539] ? do_dup2+0x450/0x450 [ 42.824062] ? __se_sys_futex+0x298/0x3b0 [ 42.828191] ? __fdget+0x1a0/0x230 [ 42.831718] ksys_ioctl+0x9b/0xc0 [ 42.835155] __x64_sys_ioctl+0x6f/0xb0 [ 42.839027] ? lockdep_hardirqs_on+0x3a8/0x5c0 [ 42.843592] do_syscall_64+0xf9/0x620 [ 42.847392] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 42.852564] RIP: 0033:0x44a3c9 [ 42.855740] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 00 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 [ 42.874628] RSP: 002b:00007ff7685901f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 42.882759] RAX: ffffffffffffffda RBX: 00000000004cb428 RCX: 000000000044a3c9 [ 42.890009] RDX: 00000000200001c0 RSI: 00000000c02064b2 RDI: 0000000000000004 [ 42.897259] RBP: 00000000004cb420 R08: 0000000000000000 R09: 0000000000000000 [ 42.904518] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cb42c [ 42.911771] R13: 00007ffee22fcb1f R14: 00007ff768590300 R15: 0000000000022000 [ 42.919028] [ 42.920638] Allocated by task 10900: [ 42.924338] kmem_cache_alloc_trace+0x12f/0x380 [ 42.928988] __vgem_gem_create+0x44/0xf0 [ 42.933030] vgem_gem_dumb_create+0xcf/0x240 [ 42.937419] drm_mode_create_dumb+0x27c/0x300 [ 42.941896] drm_ioctl_kernel+0x208/0x2a0 [ 42.946023] drm_ioctl+0x507/0x9c0 [ 42.949544] do_vfs_ioctl+0xcdb/0x12e0 [ 42.953413] ksys_ioctl+0x9b/0xc0 [ 42.956846] __x64_sys_ioctl+0x6f/0xb0 [ 42.960716] do_syscall_64+0xf9/0x620 [ 42.964514] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 42.969679] [ 42.971289] Freed by task 10900: [ 42.974640] kfree+0xcc/0x210 [ 42.977728] drm_gem_object_free+0x91/0x1c0 [ 42.982033] drm_gem_object_put_unlocked+0xd1/0x180 [ 42.987031] vgem_gem_dumb_create+0x10c/0x240 [ 42.991520] drm_mode_create_dumb+0x27c/0x300 [ 42.995999] drm_ioctl_kernel+0x208/0x2a0 [ 43.000145] drm_ioctl+0x507/0x9c0 [ 43.003683] do_vfs_ioctl+0xcdb/0x12e0 [ 43.007662] ksys_ioctl+0x9b/0xc0 [ 43.011107] __x64_sys_ioctl+0x6f/0xb0 [ 43.014980] do_syscall_64+0xf9/0x620 [ 43.018766] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 43.023934] [ 43.025545] The buggy address belongs to the object at ffff8880aa10b780 [ 43.025545] which belongs to the cache kmalloc-512 of size 512 [ 43.038201] The buggy address is located 256 bytes inside of [ 43.038201] 512-byte region [ffff8880aa10b780, ffff8880aa10b980) [ 43.050094] The buggy address belongs to the page: [ 43.055019] page:ffffea0002a842c0 count:1 mapcount:0 mapping:ffff88813bff0940 index:0xffff8880aa10b500 [ 43.064443] flags: 0xfff00000000100(slab) [ 43.068578] raw: 00fff00000000100 ffffea0002ab7188 ffffea0002c47a08 ffff88813bff0940 [ 43.076445] raw: ffff8880aa10b500 ffff8880aa10b000 0000000100000004 0000000000000000 [ 43.084304] page dumped because: kasan: bad access detected [ 43.089990] [ 43.091608] Memory state around the buggy address: [ 43.096520] ffff8880aa10b780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 43.103860] ffff8880aa10b800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 43.111220] >ffff8880aa10b880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 43.118556] ^ [ 43.121902] ffff8880aa10b900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 43.129244] ffff8880aa10b980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 43.136579] ================================================================== [ 43.143914] Disabling lock debugging due to kernel taint [ 43.150737] Kernel panic - not syncing: panic_on_warn set ... [ 43.150737] [ 43.158123] CPU: 1 PID: 10900 Comm: syz-executor767 Tainted: G B 4.19.184-syzkaller #0 [ 43.167481] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.176827] Call Trace: [ 43.179417] dump_stack+0x1fc/0x2ef [ 43.183038] panic+0x26a/0x50e [ 43.186349] ? __warn_printk+0xf3/0xf3 [ 43.190238] ? preempt_schedule_common+0x45/0xc0 [ 43.194983] ? ___preempt_schedule+0x16/0x18 [ 43.199390] ? trace_hardirqs_on+0x55/0x210 [ 43.203696] kasan_end_report+0x43/0x49 [ 43.207653] kasan_report_error.cold+0xa7/0x1b9 [ 43.212305] ? vgem_gem_dumb_create+0x22c/0x240 [ 43.216957] __asan_report_load8_noabort+0x88/0x90 [ 43.221875] ? drm_gem_object_put_unlocked+0xc0/0x180 [ 43.227045] ? vgem_gem_dumb_create+0x22c/0x240 [ 43.231782] vgem_gem_dumb_create+0x22c/0x240 [ 43.236261] drm_mode_create_dumb+0x27c/0x300 [ 43.240740] drm_ioctl_kernel+0x208/0x2a0 [ 43.244870] ? drm_mode_create_dumb+0x300/0x300 [ 43.249521] ? drm_ioctl_permit+0x210/0x210 [ 43.253824] ? __might_fault+0x192/0x1d0 [ 43.257865] drm_ioctl+0x507/0x9c0 [ 43.261384] ? drm_mode_create_dumb+0x300/0x300 [ 43.266039] ? drm_getstats+0x20/0x20 [ 43.269829] ? signal_setup_done+0xdd/0x460 [ 43.274131] ? get_signal+0x1f70/0x1f70 [ 43.278089] ? futex_exit_release+0x220/0x220 [ 43.282577] ? drm_getstats+0x20/0x20 [ 43.286361] do_vfs_ioctl+0xcdb/0x12e0 [ 43.290237] ? lock_downgrade+0x720/0x720 [ 43.294368] ? check_preemption_disabled+0x41/0x280 [ 43.299363] ? ioctl_preallocate+0x200/0x200 [ 43.303753] ? __fget+0x356/0x510 [ 43.307255] ? do_dup2+0x450/0x450 [ 43.310775] ? __se_sys_futex+0x298/0x3b0 [ 43.314902] ? __fdget+0x1a0/0x230 [ 43.318436] ksys_ioctl+0x9b/0xc0 [ 43.321874] __x64_sys_ioctl+0x6f/0xb0 [ 43.325740] ? lockdep_hardirqs_on+0x3a8/0x5c0 [ 43.330301] do_syscall_64+0xf9/0x620 [ 43.334127] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 43.339296] RIP: 0033:0x44a3c9 [ 43.342591] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 00 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 [ 43.361471] RSP: 002b:00007ff7685901f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 43.369158] RAX: ffffffffffffffda RBX: 00000000004cb428 RCX: 000000000044a3c9 [ 43.376410] RDX: 00000000200001c0 RSI: 00000000c02064b2 RDI: 0000000000000004 [ 43.383658] RBP: 00000000004cb420 R08: 0000000000000000 R09: 0000000000000000 [ 43.390905] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004cb42c [ 43.398153] R13: 00007ffee22fcb1f R14: 00007ff768590300 R15: 0000000000022000 [ 43.405999] Kernel Offset: disabled [ 43.409611] Rebooting in 86400 seconds..