Warning: Permanently added '10.128.10.24' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program syzkaller login: [ 91.864594][ T9588] ================================================================== [ 91.864656][ T9588] BUG: KASAN: use-after-free in con_shutdown+0x7f/0x90 [ 91.864666][ T9588] Write of size 8 at addr ffff888096a54108 by task syz-executor856/9588 [ 91.864669][ T9588] [ 91.864683][ T9588] CPU: 0 PID: 9588 Comm: syz-executor856 Not tainted 5.6.0-rc3-next-20200228-syzkaller #0 [ 91.864690][ T9588] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 91.864694][ T9588] Call Trace: [ 91.864710][ T9588] dump_stack+0x188/0x20d [ 91.864723][ T9588] ? con_shutdown+0x7f/0x90 [ 91.864736][ T9588] ? con_shutdown+0x7f/0x90 [ 91.864759][ T9588] print_address_description.constprop.0.cold+0xd3/0x315 [ 91.864771][ T9588] ? con_shutdown+0x7f/0x90 [ 91.864785][ T9588] ? con_shutdown+0x7f/0x90 [ 91.864794][ T9588] __kasan_report.cold+0x1a/0x32 [ 91.864812][ T9588] ? con_shutdown+0x7f/0x90 [ 91.864830][ T9588] kasan_report+0xe/0x20 [ 91.864844][ T9588] con_shutdown+0x7f/0x90 [ 91.864855][ T9588] ? update_region+0x140/0x140 [ 91.864867][ T9588] release_tty+0xca/0x450 [ 91.864883][ T9588] tty_release_struct+0x37/0x50 [ 91.864897][ T9588] tty_release+0xbc7/0xe90 [ 91.864924][ T9588] ? do_tty_hangup+0x30/0x30 [ 91.864936][ T9588] __fput+0x2da/0x850 [ 91.864964][ T9588] task_work_run+0x13f/0x1b0 [ 91.864985][ T9588] do_exit+0xb53/0x2e10 [ 91.865013][ T9588] ? mm_update_next_owner+0x7a0/0x7a0 [ 91.865027][ T9588] ? up_read+0x1a8/0x750 [ 91.865046][ T9588] ? down_read_nested+0x430/0x430 [ 91.865064][ T9588] ? handle_mm_fault+0x29e/0x660 [ 91.865085][ T9588] do_group_exit+0x125/0x340 [ 91.865103][ T9588] __x64_sys_exit_group+0x3a/0x50 [ 91.865117][ T9588] do_syscall_64+0xf6/0x790 [ 91.865136][ T9588] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 91.865146][ T9588] RIP: 0033:0x43ff38 [ 91.865159][ T9588] Code: 00 00 be 3c 00 00 00 eb 19 66 0f 1f 84 00 00 00 00 00 48 89 d7 89 f0 0f 05 48 3d 00 f0 ff ff 77 21 f4 48 89 d7 44 89 c0 0f 05 <48> 3d 00 f0 ff ff 76 e0 f7 d8 64 41 89 01 eb d8 0f 1f 84 00 00 00 [ 91.865165][ T9588] RSP: 002b:00007ffe36d29e18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 91.865177][ T9588] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 91.865184][ T9588] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 91.865191][ T9588] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 91.865197][ T9588] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 91.865204][ T9588] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 91.865232][ T9588] [ 91.865238][ T9588] Allocated by task 9588: [ 91.865250][ T9588] save_stack+0x1b/0x40 [ 91.865262][ T9588] __kasan_kmalloc.constprop.0+0xbf/0xd0 [ 91.865273][ T9588] kmem_cache_alloc_trace+0x153/0x7d0 [ 91.865282][ T9588] vc_allocate+0x1e2/0x6e0 [ 91.865290][ T9588] con_install+0x4f/0x400 [ 91.865302][ T9588] tty_init_dev+0xf5/0x460 [ 91.865310][ T9588] tty_open+0x47f/0xb30 [ 91.865322][ T9588] chrdev_open+0x219/0x5c0 [ 91.865333][ T9588] do_dentry_open+0x49e/0x1250 [ 91.865345][ T9588] path_openat+0x122a/0x3230 [ 91.865356][ T9588] do_filp_open+0x192/0x260 [ 91.865367][ T9588] do_sys_openat2+0x54c/0x740 [ 91.865378][ T9588] do_sys_open+0xc3/0x140 [ 91.865389][ T9588] do_syscall_64+0xf6/0x790 [ 91.865400][ T9588] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 91.865404][ T9588] [ 91.865409][ T9588] Freed by task 9597: [ 91.865420][ T9588] save_stack+0x1b/0x40 [ 91.865431][ T9588] __kasan_slab_free+0xf7/0x140 [ 91.865441][ T9588] kfree+0x109/0x2b0 [ 91.865450][ T9588] vt_disallocate_all+0x283/0x370 [ 91.865459][ T9588] vt_ioctl+0x79e/0x2450 [ 91.865469][ T9588] tty_ioctl+0xedd/0x1440 [ 91.865479][ T9588] ksys_ioctl+0x11a/0x180 [ 91.865488][ T9588] __x64_sys_ioctl+0x6f/0xb0 [ 91.865498][ T9588] do_syscall_64+0xf6/0x790 [ 91.865508][ T9588] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 91.865511][ T9588] [ 91.865520][ T9588] The buggy address belongs to the object at ffff888096a54000 [ 91.865520][ T9588] which belongs to the cache kmalloc-2k of size 2048 [ 91.865530][ T9588] The buggy address is located 264 bytes inside of [ 91.865530][ T9588] 2048-byte region [ffff888096a54000, ffff888096a54800) [ 91.865533][ T9588] The buggy address belongs to the page: [ 91.865544][ T9588] page:ffffea00025a9500 refcount:1 mapcount:0 mapping:0000000048c153d1 index:0x0 [ 91.865553][ T9588] flags: 0xfffe0000000200(slab) [ 91.865569][ T9588] raw: 00fffe0000000200 ffffea00026738c8 ffffea0002a14708 ffff8880aa000e00 [ 91.865582][ T9588] raw: 0000000000000000 ffff888096a54000 0000000100000001 0000000000000000 [ 91.865587][ T9588] page dumped because: kasan: bad access detected [ 91.865591][ T9588] [ 91.865595][ T9588] Memory state around the buggy address: [ 91.865605][ T9588] ffff888096a54000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 91.865614][ T9588] ffff888096a54080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 91.865624][ T9588] >ffff888096a54100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 91.865628][ T9588] ^ [ 91.865635][ T9588] ffff888096a54180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 91.865644][ T9588] ffff888096a54200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 91.865649][ T9588] ================================================================== [ 91.865653][ T9588] Disabling lock debugging due to kernel taint [ 91.865659][ T9588] Kernel panic - not syncing: panic_on_warn set ... [ 91.865672][ T9588] CPU: 0 PID: 9588 Comm: syz-executor856 Tainted: G B 5.6.0-rc3-next-20200228-syzkaller #0 [ 91.865677][ T9588] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 91.865680][ T9588] Call Trace: [ 91.865693][ T9588] dump_stack+0x188/0x20d [ 91.865708][ T9588] panic+0x2e3/0x75c [ 91.865721][ T9588] ? add_taint.cold+0x16/0x16 [ 91.865738][ T9588] ? print_shadow_for_address+0xb8/0x114 [ 91.865758][ T9588] ? trace_hardirqs_on+0x55/0x220 [ 91.865771][ T9588] ? con_shutdown+0x7f/0x90 [ 91.865779][ T9588] end_report+0x43/0x49 [ 91.865789][ T9588] ? con_shutdown+0x7f/0x90 [ 91.865797][ T9588] __kasan_report.cold+0xd/0x32 [ 91.865810][ T9588] ? con_shutdown+0x7f/0x90 [ 91.865823][ T9588] kasan_report+0xe/0x20 [ 91.865835][ T9588] con_shutdown+0x7f/0x90 [ 91.865847][ T9588] ? update_region+0x140/0x140 [ 91.865858][ T9588] release_tty+0xca/0x450 [ 91.865872][ T9588] tty_release_struct+0x37/0x50 [ 91.865884][ T9588] tty_release+0xbc7/0xe90 [ 91.865902][ T9588] ? do_tty_hangup+0x30/0x30 [ 91.865912][ T9588] __fput+0x2da/0x850 [ 91.865931][ T9588] task_work_run+0x13f/0x1b0 [ 91.865945][ T9588] do_exit+0xb53/0x2e10 [ 91.865963][ T9588] ? mm_update_next_owner+0x7a0/0x7a0 [ 91.865975][ T9588] ? up_read+0x1a8/0x750 [ 91.865989][ T9588] ? down_read_nested+0x430/0x430 [ 91.866002][ T9588] ? handle_mm_fault+0x29e/0x660 [ 91.866016][ T9588] do_group_exit+0x125/0x340 [ 91.866029][ T9588] __x64_sys_exit_group+0x3a/0x50 [ 91.866041][ T9588] do_syscall_64+0xf6/0x790 [ 91.866056][ T9588] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 91.866062][ T9588] RIP: 0033:0x43ff38 [ 91.866073][ T9588] Code: 00 00 be 3c 00 00 00 eb 19 66 0f 1f 84 00 00 00 00 00 48 89 d7 89 f0 0f 05 48 3d 00 f0 ff ff 77 21 f4 48 89 d7 44 89 c0 0f 05 <48> 3d 00 f0 ff ff 76 e0 f7 d8 64 41 89 01 eb d8 0f 1f 84 00 00 00 [ 91.866078][ T9588] RSP: 002b:00007ffe36d29e18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 91.866088][ T9588] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 91.866094][ T9588] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 91.866101][ T9588] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 91.866107][ T9588] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 91.866113][ T9588] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 91.867534][ T9588] Kernel Offset: disabled