Warning: Permanently added '10.128.0.76' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 54.960705] kauditd_printk_skb: 5 callbacks suppressed [ 54.960722] audit: type=1400 audit(1579785135.355:36): avc: denied { map } for pid=8280 comm="syz-executor163" path="/root/syz-executor163690929" dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 executing program [ 55.049636] ================================================================== [ 55.049691] BUG: KASAN: use-after-free in con_shutdown+0x85/0x90 [ 55.049702] Write of size 8 at addr ffff88809259f7c8 by task syz-executor163/8298 [ 55.049706] [ 55.049719] CPU: 0 PID: 8298 Comm: syz-executor163 Not tainted 4.19.98-syzkaller #0 [ 55.049727] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 55.049732] Call Trace: [ 55.049749] dump_stack+0x197/0x210 [ 55.049766] ? con_shutdown+0x85/0x90 [ 55.049785] print_address_description.cold+0x7c/0x20d [ 55.049801] ? con_shutdown+0x85/0x90 [ 55.049815] kasan_report.cold+0x8c/0x2ba [ 55.049830] ? set_palette+0x1c0/0x1c0 [ 55.049848] __asan_report_store8_noabort+0x17/0x20 [ 55.049862] con_shutdown+0x85/0x90 [ 55.049876] release_tty+0xe4/0x4d0 [ 55.049893] tty_release_struct+0x3c/0x50 [ 55.049909] tty_release+0xbcb/0xe90 [ 55.049932] ? tty_release_struct+0x50/0x50 [ 55.049946] __fput+0x2dd/0x8b0 [ 55.049968] ____fput+0x16/0x20 [ 55.049983] task_work_run+0x145/0x1c0 [ 55.050004] do_exit+0xc1f/0x30d0 [ 55.050022] ? get_signal+0x384/0x1fc0 [ 55.050042] ? mm_update_next_owner+0x660/0x660 [ 55.050064] ? _raw_spin_unlock_irq+0x28/0x90 [ 55.050077] ? get_signal+0x384/0x1fc0 [ 55.050091] ? _raw_spin_unlock_irq+0x28/0x90 [ 55.050110] do_group_exit+0x135/0x370 [ 55.050128] get_signal+0x3ec/0x1fc0 [ 55.050149] ? __fget+0x340/0x540 [ 55.050172] do_signal+0x95/0x1960 [ 55.050184] ? tty_vhangup+0x30/0x30 [ 55.050200] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 55.050215] ? do_vfs_ioctl+0x120/0x1380 [ 55.050229] ? selinux_file_ioctl+0x46c/0x5d0 [ 55.050247] ? setup_sigcontext+0x7d0/0x7d0 [ 55.050261] ? ioctl_preallocate+0x210/0x210 [ 55.050278] ? selinux_file_mprotect+0x620/0x620 [ 55.050308] ? __x64_sys_futex+0x40d/0x590 [ 55.050327] ? exit_to_usermode_loop+0x43/0x2c0 [ 55.050341] ? do_syscall_64+0x53d/0x620 [ 55.050355] ? exit_to_usermode_loop+0x43/0x2c0 [ 55.050372] ? lockdep_hardirqs_on+0x415/0x5d0 [ 55.050388] ? trace_hardirqs_on+0x67/0x220 [ 55.050408] exit_to_usermode_loop+0x244/0x2c0 [ 55.050428] do_syscall_64+0x53d/0x620 [ 55.050448] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 55.050459] RIP: 0033:0x4467b9 [ 55.050471] Code: Bad RIP value. [ 55.050479] RSP: 002b:00007fc97bf52db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 55.050493] RAX: fffffffffffffe00 RBX: 00000000006dbc28 RCX: 00000000004467b9 [ 55.050501] RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000006dbc28 [ 55.050509] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000 [ 55.050517] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c [ 55.050526] R13: 00007ffc2287e90f R14: 00007fc97bf539c0 R15: 000000000000002d [ 55.050545] [ 55.050551] Allocated by task 8298: [ 55.050564] save_stack+0x45/0xd0 [ 55.050575] kasan_kmalloc+0xce/0xf0 [ 55.050587] kmem_cache_alloc_trace+0x152/0x760 [ 55.050599] vc_allocate+0x1f5/0x760 [ 55.050610] con_install+0x52/0x410 [ 55.050622] tty_init_dev+0xf7/0x460 [ 55.050634] tty_open+0x4bf/0xb70 [ 55.050644] chrdev_open+0x245/0x6b0 [ 55.050655] do_dentry_open+0x4c3/0x1210 [ 55.050693] vfs_open+0xa0/0xd0 [ 55.050704] path_openat+0x10d7/0x45e0 [ 55.050715] do_filp_open+0x1a1/0x280 [ 55.050726] do_sys_open+0x3fe/0x550 [ 55.050737] __x64_sys_open+0x7e/0xc0 [ 55.050749] do_syscall_64+0xfd/0x620 [ 55.050762] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 55.050766] [ 55.050771] Freed by task 8291: [ 55.050782] save_stack+0x45/0xd0 [ 55.050794] __kasan_slab_free+0x102/0x150 [ 55.050808] kasan_slab_free+0xe/0x10 [ 55.050818] kfree+0xcf/0x220 [ 55.050829] vt_disallocate_all+0x2bd/0x3e0 [ 55.050840] vt_ioctl+0xc38/0x2530 [ 55.050852] tty_ioctl+0x7f3/0x1510 [ 55.050863] do_vfs_ioctl+0xd5f/0x1380 [ 55.050875] ksys_ioctl+0xab/0xd0 [ 55.050886] __x64_sys_ioctl+0x73/0xb0 [ 55.050899] do_syscall_64+0xfd/0x620 [ 55.050911] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 55.050915] [ 55.050925] The buggy address belongs to the object at ffff88809259f6c0 [ 55.050925] which belongs to the cache kmalloc-2048 of size 2048 [ 55.050936] The buggy address is located 264 bytes inside of [ 55.050936] 2048-byte region [ffff88809259f6c0, ffff88809259fec0) [ 55.050940] The buggy address belongs to the page: [ 55.050952] page:ffffea0002496780 count:1 mapcount:0 mapping:ffff88812c31cc40 index:0x0 compound_mapcount: 0 [ 55.050966] flags: 0xfffe0000008100(slab|head) [ 55.050986] raw: 00fffe0000008100 ffffea0002682c88 ffffea00027ed488 ffff88812c31cc40 [ 55.051001] raw: 0000000000000000 ffff88809259e5c0 0000000100000003 0000000000000000 [ 55.051007] page dumped because: kasan: bad access detected [ 55.051010] [ 55.051014] Memory state around the buggy address: [ 55.051025] ffff88809259f680: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 55.051037] ffff88809259f700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 55.051048] >ffff88809259f780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 55.051053] ^ [ 55.051063] ffff88809259f800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 55.051074] ffff88809259f880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 55.051079] ================================================================== [ 55.051084] Disabling lock debugging due to kernel taint [ 55.051090] Kernel panic - not syncing: panic_on_warn set ... [ 55.051090] [ 55.051104] CPU: 0 PID: 8298 Comm: syz-executor163 Tainted: G B 4.19.98-syzkaller #0 [ 55.051112] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 55.051115] Call Trace: [ 55.051129] dump_stack+0x197/0x210 [ 55.051145] ? con_shutdown+0x85/0x90 [ 55.051155] panic+0x26a/0x50e [ 55.051166] ? __warn_printk+0xf3/0xf3 [ 55.051183] ? lock_downgrade+0x880/0x880 [ 55.051198] ? trace_hardirqs_on+0x67/0x220 [ 55.051210] ? trace_hardirqs_on+0x5e/0x220 [ 55.051226] ? con_shutdown+0x85/0x90 [ 55.051240] kasan_end_report+0x47/0x4f [ 55.051255] kasan_report.cold+0xa9/0x2ba [ 55.051269] ? set_palette+0x1c0/0x1c0 [ 55.051284] __asan_report_store8_noabort+0x17/0x20 [ 55.051297] con_shutdown+0x85/0x90 [ 55.051310] release_tty+0xe4/0x4d0 [ 55.051326] tty_release_struct+0x3c/0x50 [ 55.051339] tty_release+0xbcb/0xe90 [ 55.051357] ? tty_release_struct+0x50/0x50 [ 55.051369] __fput+0x2dd/0x8b0 [ 55.051385] ____fput+0x16/0x20 [ 55.051397] task_work_run+0x145/0x1c0 [ 55.051412] do_exit+0xc1f/0x30d0 [ 55.051427] ? get_signal+0x384/0x1fc0 [ 55.051442] ? mm_update_next_owner+0x660/0x660 [ 55.051457] ? _raw_spin_unlock_irq+0x28/0x90 [ 55.051469] ? get_signal+0x384/0x1fc0 [ 55.051481] ? _raw_spin_unlock_irq+0x28/0x90 [ 55.051496] do_group_exit+0x135/0x370 [ 55.051512] get_signal+0x3ec/0x1fc0 [ 55.051527] ? __fget+0x340/0x540 [ 55.051545] do_signal+0x95/0x1960 [ 55.051556] ? tty_vhangup+0x30/0x30 [ 55.051570] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 55.051582] ? do_vfs_ioctl+0x120/0x1380 [ 55.051594] ? selinux_file_ioctl+0x46c/0x5d0 [ 55.051608] ? setup_sigcontext+0x7d0/0x7d0 [ 55.051622] ? ioctl_preallocate+0x210/0x210 [ 55.051635] ? selinux_file_mprotect+0x620/0x620 [ 55.051655] ? __x64_sys_futex+0x40d/0x590 [ 55.051680] ? exit_to_usermode_loop+0x43/0x2c0 [ 55.051693] ? do_syscall_64+0x53d/0x620 [ 55.051707] ? exit_to_usermode_loop+0x43/0x2c0 [ 55.051722] ? lockdep_hardirqs_on+0x415/0x5d0 [ 55.051735] ? trace_hardirqs_on+0x67/0x220 [ 55.051751] exit_to_usermode_loop+0x244/0x2c0 [ 55.051768] do_syscall_64+0x53d/0x620 [ 55.051784] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 55.051793] RIP: 0033:0x4467b9 [ 55.051803] Code: Bad RIP value. [ 55.051810] RSP: 002b:00007fc97bf52db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca [ 55.051823] RAX: fffffffffffffe00 RBX: 00000000006dbc28 RCX: 00000000004467b9 [ 55.051830] RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000006dbc28 [ 55.051837] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000 [ 55.051845] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c [ 55.051852] R13: 00007ffc2287e90f R14: 00007fc97bf539c0 R15: 000000000000002d [ 55.053189] Kernel Offset: disabled