[ 35.705055] audit: type=1800 audit(1585471458.245:33): pid=7256 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op="collect_data" cause="failed(directio)" comm="startpar" name="rc.local" dev="sda1" ino=2465 res=0 [ 35.732297] audit: type=1800 audit(1585471458.245:34): pid=7256 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op="collect_data" cause="failed(directio)" comm="startpar" name="rmnologin" dev="sda1" ino=2456 res=0 Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 37.411457] random: sshd: uninitialized urandom read (32 bytes read) [ 37.622943] audit: type=1400 audit(1585471460.165:35): avc: denied { map } for pid=7430 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 [ 37.674038] random: sshd: uninitialized urandom read (32 bytes read) [ 38.487241] random: sshd: uninitialized urandom read (32 bytes read) [ 44.916752] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.54' (ECDSA) to the list of known hosts. [ 50.483749] random: sshd: uninitialized urandom read (32 bytes read) executing program executing program executing program executing program executing program executing program executing program [ 50.621264] audit: type=1400 audit(1585471473.165:36): avc: denied { map } for pid=7442 comm="syz-executor729" path="/root/syz-executor729721826" dev="sda1" ino=16484 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 50.692476] ================================================================== [ 50.692511] BUG: KASAN: use-after-free in con_shutdown+0x7f/0x90 [ 50.692518] Write of size 8 at addr ffff888093e03748 by task syz-executor729/7450 [ 50.692520] [ 50.692529] CPU: 1 PID: 7450 Comm: syz-executor729 Not tainted 4.14.174-syzkaller #0 [ 50.692544] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.692547] Call Trace: [ 50.692561] dump_stack+0x13e/0x194 [ 50.692571] ? con_shutdown+0x7f/0x90 [ 50.692583] print_address_description.cold+0x7c/0x1e2 [ 50.692591] ? con_shutdown+0x7f/0x90 [ 50.692599] kasan_report.cold+0xa9/0x2ae [ 50.692607] ? set_palette+0x130/0x130 [ 50.692615] con_shutdown+0x7f/0x90 [ 50.692624] release_tty+0xb6/0x7a0 [ 50.692634] tty_release_struct+0x37/0x50 [ 50.692642] tty_release+0xaa6/0xd60 [ 50.692655] ? tty_release_struct+0x50/0x50 [ 50.692662] __fput+0x25f/0x790 [ 50.692677] task_work_run+0x113/0x190 [ 50.692689] do_exit+0x9f2/0x2b00 [ 50.692698] ? __do_page_fault+0x4e4/0xb40 [ 50.692709] ? mm_update_next_owner+0x5b0/0x5b0 [ 50.692719] ? lock_downgrade+0x6e0/0x6e0 [ 50.692733] do_group_exit+0x100/0x310 [ 50.692744] SyS_exit_group+0x19/0x20 [ 50.692750] ? do_group_exit+0x310/0x310 [ 50.692759] do_syscall_64+0x1d5/0x640 [ 50.692773] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 50.692780] RIP: 0033:0x43ff38 [ 50.692785] RSP: 002b:00007ffc6b69a188 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 50.692794] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 50.692799] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 50.692803] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 50.692807] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 50.692812] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 50.692826] [ 50.692830] Allocated by task 7450: [ 50.692838] save_stack+0x32/0xa0 [ 50.692845] kasan_kmalloc+0xbf/0xe0 [ 50.692851] kmem_cache_alloc_trace+0x14d/0x7b0 [ 50.692857] vc_allocate+0x142/0x550 [ 50.692863] con_install+0x4f/0x3e0 [ 50.692877] tty_init_dev+0xe1/0x3a0 [ 50.692884] tty_open+0x410/0x9c0 [ 50.692890] chrdev_open+0x1fc/0x540 [ 50.692898] do_dentry_open+0x732/0xe90 [ 50.692905] vfs_open+0x105/0x220 [ 50.692912] path_openat+0x8ca/0x3c50 [ 50.692918] do_filp_open+0x18e/0x250 [ 50.692924] do_sys_open+0x29d/0x3f0 [ 50.692930] do_syscall_64+0x1d5/0x640 [ 50.692937] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 50.692939] [ 50.692943] Freed by task 7451: [ 50.692948] save_stack+0x32/0xa0 [ 50.692955] kasan_slab_free+0x75/0xc0 [ 50.692960] kfree+0xcb/0x260 [ 50.692966] vt_disallocate_all+0x25c/0x340 [ 50.692971] vt_ioctl+0x6e3/0x1f00 [ 50.692977] tty_ioctl+0x6c5/0x1220 [ 50.692984] do_vfs_ioctl+0x75a/0xfe0 [ 50.692990] SyS_ioctl+0x7f/0xb0 [ 50.692997] do_syscall_64+0x1d5/0x640 [ 50.693004] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 50.693006] [ 50.693011] The buggy address belongs to the object at ffff888093e03640 [ 50.693011] which belongs to the cache kmalloc-2048 of size 2048 [ 50.693017] The buggy address is located 264 bytes inside of [ 50.693017] 2048-byte region [ffff888093e03640, ffff888093e03e40) [ 50.693020] The buggy address belongs to the page: [ 50.693027] page:ffffea00024f8080 count:1 mapcount:0 mapping:ffff888093e02540 index:0x0 compound_mapcount: 0 [ 50.693037] flags: 0xfffe0000008100(slab|head) [ 50.693046] raw: 00fffe0000008100 ffff888093e02540 0000000000000000 0000000100000003 [ 50.693055] raw: ffffea00024b44a0 ffffea00024f1a20 ffff88812fe56c40 0000000000000000 [ 50.693058] page dumped because: kasan: bad access detected [ 50.693060] [ 50.693063] Memory state around the buggy address: [ 50.693070] ffff888093e03600: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 50.693075] ffff888093e03680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 50.693081] >ffff888093e03700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 50.693085] ^ [ 50.693091] ffff888093e03780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 50.693097] ffff888093e03800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 50.693100] ================================================================== [ 50.693103] Disabling lock debugging due to kernel taint [ 50.693135] Kernel panic - not syncing: panic_on_warn set ... [ 50.693135] [ 50.693142] CPU: 1 PID: 7450 Comm: syz-executor729 Tainted: G B 4.14.174-syzkaller #0 [ 50.693146] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.693148] Call Trace: [ 50.693157] dump_stack+0x13e/0x194 [ 50.693165] panic+0x1f9/0x42d [ 50.693172] ? add_taint.cold+0x16/0x16 [ 50.693184] ? con_shutdown+0x7f/0x90 [ 50.693190] kasan_end_report+0x43/0x49 [ 50.693197] kasan_report.cold+0x12f/0x2ae [ 50.693204] ? set_palette+0x130/0x130 [ 50.693211] con_shutdown+0x7f/0x90 [ 50.693218] release_tty+0xb6/0x7a0 [ 50.693226] tty_release_struct+0x37/0x50 [ 50.693233] tty_release+0xaa6/0xd60 [ 50.693244] ? tty_release_struct+0x50/0x50 [ 50.693250] __fput+0x25f/0x790 [ 50.693260] task_work_run+0x113/0x190 [ 50.693269] do_exit+0x9f2/0x2b00 [ 50.693276] ? __do_page_fault+0x4e4/0xb40 [ 50.693284] ? mm_update_next_owner+0x5b0/0x5b0 [ 50.693292] ? lock_downgrade+0x6e0/0x6e0 [ 50.693302] do_group_exit+0x100/0x310 [ 50.693310] SyS_exit_group+0x19/0x20 [ 50.693316] ? do_group_exit+0x310/0x310 [ 50.693323] do_syscall_64+0x1d5/0x640 [ 50.693333] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 50.693338] RIP: 0033:0x43ff38 [ 50.693342] RSP: 002b:00007ffc6b69a188 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 50.693349] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ff38 [ 50.693353] RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 [ 50.693357] RBP: 00000000004bf950 R08: 00000000000000e7 R09: ffffffffffffffd0 [ 50.693361] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 [ 50.693365] R13: 00000000006d2180 R14: 0000000000000000 R15: 0000000000000000 [ 50.694535] Kernel Offset: disabled