[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [ 41.082200] audit: type=1800 audit(1576234205.551:33): pid=7455 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 Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 45.107493] kauditd_printk_skb: 1 callbacks suppressed [ 45.107506] audit: type=1400 audit(1576234209.581:35): avc: denied { map } for pid=7632 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 Warning: Permanently added '10.128.10.5' (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 [ 66.979316] audit: type=1400 audit(1576234231.451:36): avc: denied { map } for pid=7644 comm="syz-executor795" path="/root/syz-executor795529962" 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 67.423385] ================================================================== [ 67.431181] BUG: KASAN: use-after-free in n_tty_receive_buf_common+0x26a4/0x2ab0 [ 67.431195] Read of size 1 at addr ffff88808ef9b0c1 by task syz-executor795/7728 [ 67.431198] [ 67.431213] CPU: 1 PID: 7728 Comm: syz-executor795 Not tainted 4.19.89-syzkaller #0 [ 67.431221] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 67.431225] Call Trace: [ 67.431242] dump_stack+0x197/0x210 [ 67.431260] ? n_tty_receive_buf_common+0x26a4/0x2ab0 [ 67.431277] print_address_description.cold+0x7c/0x20d [ 67.431292] ? n_tty_receive_buf_common+0x26a4/0x2ab0 [ 67.431306] kasan_report.cold+0x8c/0x2ba [ 67.431327] __asan_report_load1_noabort+0x14/0x20 [ 67.431340] n_tty_receive_buf_common+0x26a4/0x2ab0 [ 67.431355] ? find_held_lock+0x35/0x130 [ 67.431384] n_tty_receive_buf2+0x34/0x40 [ 67.431400] tty_ldisc_receive_buf+0xad/0x1c0 [ 67.431413] ? add_wait_queue+0x112/0x170 [ 67.431424] ? n_tty_receive_buf_common+0x2ab0/0x2ab0 [ 67.431442] paste_selection+0x1ff/0x443 [ 67.431460] ? set_selection+0x1370/0x1370 [ 67.431478] ? lock_downgrade+0x880/0x880 [ 67.431490] ? wake_up_q+0x100/0x100 [ 67.431515] tioclinux+0x133/0x470 [ 67.543871] vt_ioctl+0x19ab/0x2530 [ 67.543890] ? complete_change_console+0x3a0/0x3a0 [ 67.552456] ? avc_has_extended_perms+0xa78/0x10f0 [ 67.552474] ? lock_downgrade+0x880/0x880 [ 67.552491] ? avc_ss_reset+0x190/0x190 [ 67.552505] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 67.552522] ? tty_jobctrl_ioctl+0x50/0xcd0 [ 67.552535] ? complete_change_console+0x3a0/0x3a0 [ 67.552549] tty_ioctl+0x7f3/0x1510 [ 67.552564] ? tty_vhangup+0x30/0x30 [ 67.552576] ? thp_get_unmapped_area+0x1f0/0x1f0 [ 67.552596] ? __handle_mm_fault+0x7d1/0x3f80 [ 67.596666] ? __might_sleep+0x95/0x190 [ 67.596684] ? tty_vhangup+0x30/0x30 [ 67.596702] do_vfs_ioctl+0xd5f/0x1380 [ 67.596718] ? selinux_file_ioctl+0x46f/0x5e0 [ 67.596731] ? selinux_file_ioctl+0x125/0x5e0 [ 67.596745] ? ioctl_preallocate+0x210/0x210 [ 67.596759] ? selinux_file_mprotect+0x620/0x620 [ 67.596775] ? gup_pgd_range+0x1afc/0x3910 [ 67.596789] ? write_comp_data+0x5b/0x70 [ 67.596807] ? up_read+0x1a/0x110 [ 67.596820] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 67.596837] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 67.596851] ? security_file_ioctl+0x8d/0xc0 [ 67.596868] ksys_ioctl+0xab/0xd0 [ 67.596886] __x64_sys_ioctl+0x73/0xb0 [ 67.596901] do_syscall_64+0xfd/0x620 [ 67.596921] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 67.670200] RIP: 0033:0x441319 [ 67.670213] Code: e8 ac e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 67.670224] RSP: 002b:00007ffd31b7c7f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 67.700095] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441319 [ 67.700103] RDX: 0000000020000000 RSI: 000000000000541c RDI: 0000000000000003 [ 67.700109] RBP: 000000000001070d R08: 000000000000000d R09: 00000000004002c8 [ 67.700115] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402090 [ 67.700122] R13: 0000000000402120 R14: 0000000000000000 R15: 0000000000000000 [ 67.700141] [ 67.700149] Allocated by task 7726: [ 67.700168] save_stack+0x45/0xd0 [ 67.700180] kasan_kmalloc+0xce/0xf0 [ 67.700189] __kmalloc+0x15d/0x750 [ 67.700202] set_selection+0x7e4/0x1370 [ 67.700214] tioclinux+0x11c/0x470 [ 67.700224] vt_ioctl+0x19ab/0x2530 [ 67.700233] tty_ioctl+0x7f3/0x1510 [ 67.700244] do_vfs_ioctl+0xd5f/0x1380 [ 67.700254] ksys_ioctl+0xab/0xd0 [ 67.700264] __x64_sys_ioctl+0x73/0xb0 [ 67.700277] do_syscall_64+0xfd/0x620 [ 67.700291] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 67.700295] [ 67.700300] Freed by task 7727: [ 67.700310] save_stack+0x45/0xd0 [ 67.700321] __kasan_slab_free+0x102/0x150 [ 67.700332] kasan_slab_free+0xe/0x10 [ 67.700347] kfree+0xcf/0x220 [ 67.807697] set_selection+0x801/0x1370 [ 67.807708] tioclinux+0x11c/0x470 [ 67.807717] vt_ioctl+0x19ab/0x2530 [ 67.807726] tty_ioctl+0x7f3/0x1510 [ 67.807737] do_vfs_ioctl+0xd5f/0x1380 [ 67.807747] ksys_ioctl+0xab/0xd0 [ 67.807757] __x64_sys_ioctl+0x73/0xb0 [ 67.807770] do_syscall_64+0xfd/0x620 [ 67.807784] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 67.807788] [ 67.807798] The buggy address belongs to the object at ffff88808ef9b0c0 [ 67.807798] which belongs to the cache kmalloc-512 of size 512 [ 67.807809] The buggy address is located 1 bytes inside of [ 67.807809] 512-byte region [ffff88808ef9b0c0, ffff88808ef9b2c0) [ 67.807820] The buggy address belongs to the page: [ 67.807837] page:ffffea00023be6c0 count:1 mapcount:0 mapping:ffff88812c31c940 index:0x0 [ 67.881703] flags: 0xfffe0000000100(slab) [ 67.881720] raw: 00fffe0000000100 ffffea00023be5c8 ffffea00023be708 ffff88812c31c940 [ 67.881732] raw: 0000000000000000 ffff88808ef9b0c0 0000000100000006 0000000000000000 [ 67.881736] page dumped because: kasan: bad access detected [ 67.881739] [ 67.881743] Memory state around the buggy address: [ 67.881753] ffff88808ef9af80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 67.881762] ffff88808ef9b000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 67.881772] >ffff88808ef9b080: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 67.881777] ^ [ 67.881786] ffff88808ef9b100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 67.881796] ffff88808ef9b180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 67.881800] ================================================================== [ 67.881804] Disabling lock debugging due to kernel taint [ 67.882175] Kernel panic - not syncing: panic_on_warn set ... [ 67.882175] [ 67.976212] CPU: 1 PID: 7728 Comm: syz-executor795 Tainted: G B 4.19.89-syzkaller #0 [ 67.976219] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 67.976223] Call Trace: [ 67.976244] dump_stack+0x197/0x210 [ 67.976260] ? n_tty_receive_buf_common+0x26a4/0x2ab0 [ 67.976271] panic+0x26a/0x50e [ 67.976282] ? __warn_printk+0xf3/0xf3 [ 67.976295] ? n_tty_receive_buf_common+0x26a4/0x2ab0 [ 67.976308] ? preempt_schedule+0x4b/0x60 [ 67.976322] ? ___preempt_schedule+0x16/0x18 [ 67.976335] ? trace_hardirqs_on+0x5e/0x220 [ 67.976349] ? n_tty_receive_buf_common+0x26a4/0x2ab0 [ 67.976361] kasan_end_report+0x47/0x4f [ 67.976374] kasan_report.cold+0xa9/0x2ba [ 67.976389] __asan_report_load1_noabort+0x14/0x20 [ 67.976401] n_tty_receive_buf_common+0x26a4/0x2ab0 [ 67.976414] ? find_held_lock+0x35/0x130 [ 67.976435] n_tty_receive_buf2+0x34/0x40 [ 67.976446] tty_ldisc_receive_buf+0xad/0x1c0 [ 67.976463] ? add_wait_queue+0x112/0x170 [ 68.073334] ? n_tty_receive_buf_common+0x2ab0/0x2ab0 [ 68.073350] paste_selection+0x1ff/0x443 [ 68.073365] ? set_selection+0x1370/0x1370 [ 68.073381] ? lock_downgrade+0x880/0x880 [ 68.073393] ? wake_up_q+0x100/0x100 [ 68.073410] tioclinux+0x133/0x470 [ 68.073422] vt_ioctl+0x19ab/0x2530 [ 68.073436] ? complete_change_console+0x3a0/0x3a0 [ 68.073450] ? avc_has_extended_perms+0xa78/0x10f0 [ 68.073467] ? lock_downgrade+0x880/0x880 [ 68.115805] ? avc_ss_reset+0x190/0x190 [ 68.115818] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 68.115832] ? tty_jobctrl_ioctl+0x50/0xcd0 [ 68.115844] ? complete_change_console+0x3a0/0x3a0 [ 68.115862] tty_ioctl+0x7f3/0x1510 [ 68.115875] ? tty_vhangup+0x30/0x30 [ 68.115888] ? thp_get_unmapped_area+0x1f0/0x1f0 [ 68.115905] ? __handle_mm_fault+0x7d1/0x3f80 [ 68.115923] ? __might_sleep+0x95/0x190 [ 68.115935] ? tty_vhangup+0x30/0x30 [ 68.115949] do_vfs_ioctl+0xd5f/0x1380 [ 68.115964] ? selinux_file_ioctl+0x46f/0x5e0 [ 68.115974] ? selinux_file_ioctl+0x125/0x5e0 [ 68.115989] ? ioctl_preallocate+0x210/0x210 [ 68.176200] ? selinux_file_mprotect+0x620/0x620 [ 68.176216] ? gup_pgd_range+0x1afc/0x3910 [ 68.176228] ? write_comp_data+0x5b/0x70 [ 68.176243] ? up_read+0x1a/0x110 [ 68.176261] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 68.176275] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 68.176287] ? security_file_ioctl+0x8d/0xc0 [ 68.176301] ksys_ioctl+0xab/0xd0 [ 68.176314] __x64_sys_ioctl+0x73/0xb0 [ 68.176331] do_syscall_64+0xfd/0x620 [ 68.219506] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 68.219514] RIP: 0033:0x441319 [ 68.219527] Code: e8 ac e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 68.219533] RSP: 002b:00007ffd31b7c7f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 68.219545] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441319 [ 68.219552] RDX: 0000000020000000 RSI: 000000000000541c RDI: 0000000000000003 [ 68.219558] RBP: 000000000001070d R08: 000000000000000d R09: 00000000004002c8 [ 68.219565] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000402090 [ 68.219577] R13: 0000000000402120 R14: 0000000000000000 R15: 0000000000000000 [ 68.220890] Kernel Offset: disabled [ 68.295958] Rebooting in 86400 seconds..