[ 43.078169] audit: type=1800 audit(1575743220.724:32): pid=7700 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="ssh" dev="sda1" ino=2450 res=0 Starting mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 48.028536] kauditd_printk_skb: 2 callbacks suppressed [ 48.028551] audit: type=1400 audit(1575743225.754:35): avc: denied { map } for pid=7873 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 '10.128.0.158' (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 [ 54.639002] audit: type=1400 audit(1575743232.364:36): avc: denied { map } for pid=7885 comm="syz-executor086" path="/root/syz-executor086563204" 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 54.874881] ================================================================== [ 54.874919] BUG: KASAN: use-after-free in n_tty_receive_buf_common+0x24b0/0x28e0 [ 54.874929] Read of size 1 at addr ffff88808bb56841 by task syz-executor086/7933 [ 54.874932] [ 54.874945] CPU: 0 PID: 7933 Comm: syz-executor086 Not tainted 4.19.88-syzkaller #0 [ 54.874952] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 54.874957] Call Trace: [ 54.874972] dump_stack+0x197/0x210 [ 54.874988] ? n_tty_receive_buf_common+0x24b0/0x28e0 [ 54.875005] print_address_description.cold+0x7c/0x20d [ 54.875019] ? n_tty_receive_buf_common+0x24b0/0x28e0 [ 54.875033] kasan_report.cold+0x8c/0x2ba [ 54.875053] __asan_report_load1_noabort+0x14/0x20 [ 54.875066] n_tty_receive_buf_common+0x24b0/0x28e0 [ 54.875101] n_tty_receive_buf2+0x34/0x40 [ 54.875118] tty_ldisc_receive_buf+0xad/0x1c0 [ 54.875133] ? add_wait_queue+0x112/0x170 [ 54.875145] ? n_tty_receive_buf_common+0x28e0/0x28e0 [ 54.875161] paste_selection+0x1ff/0x443 [ 54.875177] ? set_selection+0x1370/0x1370 [ 54.875188] ? lock_downgrade+0x880/0x880 [ 54.875197] ? wake_up_q+0x100/0x100 [ 54.875211] tioclinux+0x133/0x470 [ 54.875220] vt_ioctl+0x19ab/0x2530 [ 54.875230] ? complete_change_console+0x3a0/0x3a0 [ 54.875241] ? avc_has_extended_perms+0xa78/0x10f0 [ 54.875268] ? fs_reclaim_acquire+0x20/0x20 [ 54.875285] ? avc_ss_reset+0x190/0x190 [ 54.875294] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 54.875304] ? tty_jobctrl_ioctl+0x50/0xcd0 [ 54.875312] ? complete_change_console+0x3a0/0x3a0 [ 54.875323] tty_ioctl+0x7f3/0x1510 [ 54.875333] ? rcu_read_lock_sched_held+0x110/0x130 [ 54.875342] ? tty_vhangup+0x30/0x30 [ 54.875356] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 54.875369] ? __might_sleep+0x95/0x190 [ 54.875376] ? find_held_lock+0x35/0x130 [ 54.875385] ? tty_vhangup+0x30/0x30 [ 54.875395] do_vfs_ioctl+0xd5f/0x1380 [ 54.875403] ? selinux_file_ioctl+0x46f/0x5e0 [ 54.875411] ? selinux_file_ioctl+0x125/0x5e0 [ 54.875420] ? ioctl_preallocate+0x210/0x210 [ 54.875427] ? selinux_file_mprotect+0x620/0x620 [ 54.875438] ? __sanitizer_cov_trace_cmp4+0xb/0x20 [ 54.875447] ? __fd_install+0x200/0x640 [ 54.875456] ? fd_install+0x4d/0x60 [ 54.875466] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 54.875474] ? security_file_ioctl+0x8d/0xc0 [ 54.875483] ksys_ioctl+0xab/0xd0 [ 54.875493] __x64_sys_ioctl+0x73/0xb0 [ 54.875503] do_syscall_64+0xfd/0x620 [ 54.875514] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 54.875521] RIP: 0033:0x441399 [ 54.875530] 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 [ 54.875535] RSP: 002b:00007ffe022fda78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 54.875543] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441399 [ 54.875548] RDX: 0000000020000040 RSI: 000000000000541c RDI: 0000000000000004 [ 54.875552] RBP: 000000000000d5f3 R08: 00000000004002c8 R09: 00000000004002c8 [ 54.875557] R10: 000000000000000d R11: 0000000000000246 R12: 0000000000402110 [ 54.875561] R13: 00000000004021a0 R14: 0000000000000000 R15: 0000000000000000 [ 54.875572] [ 54.875576] Allocated by task 7935: [ 54.875584] save_stack+0x45/0xd0 [ 54.875591] kasan_kmalloc+0xce/0xf0 [ 54.875597] __kmalloc+0x15d/0x750 [ 54.875604] set_selection+0x7e4/0x1370 [ 54.875610] tioclinux+0x11c/0x470 [ 54.875616] vt_ioctl+0x19ab/0x2530 [ 54.875623] tty_ioctl+0x7f3/0x1510 [ 54.875629] do_vfs_ioctl+0xd5f/0x1380 [ 54.875635] ksys_ioctl+0xab/0xd0 [ 54.875641] __x64_sys_ioctl+0x73/0xb0 [ 54.875648] do_syscall_64+0xfd/0x620 [ 54.875655] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 54.875657] [ 54.875660] Freed by task 7936: [ 54.875666] save_stack+0x45/0xd0 [ 54.875673] __kasan_slab_free+0x102/0x150 [ 54.875679] kasan_slab_free+0xe/0x10 [ 54.875685] kfree+0xcf/0x220 [ 54.875692] set_selection+0x801/0x1370 [ 54.875698] tioclinux+0x11c/0x470 [ 54.875704] vt_ioctl+0x19ab/0x2530 [ 54.875711] tty_ioctl+0x7f3/0x1510 [ 54.875717] do_vfs_ioctl+0xd5f/0x1380 [ 54.875723] ksys_ioctl+0xab/0xd0 [ 54.875730] __x64_sys_ioctl+0x73/0xb0 [ 54.875736] do_syscall_64+0xfd/0x620 [ 54.875743] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 54.875745] [ 54.875751] The buggy address belongs to the object at ffff88808bb56840 [ 54.875751] which belongs to the cache kmalloc-512 of size 512 [ 54.875758] The buggy address is located 1 bytes inside of [ 54.875758] 512-byte region [ffff88808bb56840, ffff88808bb56a40) [ 54.875760] The buggy address belongs to the page: [ 54.875767] page:ffffea00022ed580 count:1 mapcount:0 mapping:ffff88812c31c940 index:0x0 [ 54.875775] flags: 0xfffe0000000100(slab) [ 54.875791] raw: 00fffe0000000100 ffffea00022af1c8 ffffea00023fdb48 ffff88812c31c940 [ 54.875806] raw: 0000000000000000 ffff88808bb560c0 0000000100000006 0000000000000000 [ 54.875812] page dumped because: kasan: bad access detected [ 54.875815] [ 54.875819] Memory state around the buggy address: [ 54.875830] ffff88808bb56700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 54.875840] ffff88808bb56780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 54.875850] >ffff88808bb56800: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 54.875856] ^ [ 54.875866] ffff88808bb56880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 54.875876] ffff88808bb56900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 54.875881] ================================================================== [ 54.875886] Disabling lock debugging due to kernel taint [ 54.875893] Kernel panic - not syncing: panic_on_warn set ... [ 54.875893] [ 54.875904] CPU: 0 PID: 7933 Comm: syz-executor086 Tainted: G B 4.19.88-syzkaller #0 [ 54.875908] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 54.875910] Call Trace: [ 54.875918] dump_stack+0x197/0x210 [ 54.875927] ? n_tty_receive_buf_common+0x24b0/0x28e0 [ 54.875934] panic+0x26a/0x50e [ 54.875940] ? __warn_printk+0xf3/0xf3 [ 54.875948] ? lock_downgrade+0x880/0x880 [ 54.875957] ? trace_hardirqs_on+0x67/0x220 [ 54.875964] ? trace_hardirqs_on+0x5e/0x220 [ 54.875972] ? n_tty_receive_buf_common+0x24b0/0x28e0 [ 54.875980] kasan_end_report+0x47/0x4f [ 54.875987] kasan_report.cold+0xa9/0x2ba [ 54.875996] __asan_report_load1_noabort+0x14/0x20 [ 54.876003] n_tty_receive_buf_common+0x24b0/0x28e0 [ 54.876016] n_tty_receive_buf2+0x34/0x40 [ 54.876024] tty_ldisc_receive_buf+0xad/0x1c0 [ 54.876031] ? add_wait_queue+0x112/0x170 [ 54.876038] ? n_tty_receive_buf_common+0x28e0/0x28e0 [ 54.876046] paste_selection+0x1ff/0x443 [ 54.876055] ? set_selection+0x1370/0x1370 [ 54.876063] ? lock_downgrade+0x880/0x880 [ 54.876069] ? wake_up_q+0x100/0x100 [ 54.876079] tioclinux+0x133/0x470 [ 54.876086] vt_ioctl+0x19ab/0x2530 [ 54.876095] ? complete_change_console+0x3a0/0x3a0 [ 54.876102] ? avc_has_extended_perms+0xa78/0x10f0 [ 54.876109] ? fs_reclaim_acquire+0x20/0x20 [ 54.876119] ? avc_ss_reset+0x190/0x190 [ 54.876126] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 54.876137] ? tty_jobctrl_ioctl+0x50/0xcd0 [ 54.876149] ? complete_change_console+0x3a0/0x3a0 [ 54.876163] tty_ioctl+0x7f3/0x1510 [ 54.876176] ? rcu_read_lock_sched_held+0x110/0x130 [ 54.876190] ? tty_vhangup+0x30/0x30 [ 54.876208] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 54.876220] ? __might_sleep+0x95/0x190 [ 54.876226] ? find_held_lock+0x35/0x130 [ 54.876234] ? tty_vhangup+0x30/0x30 [ 54.876241] do_vfs_ioctl+0xd5f/0x1380 [ 54.876248] ? selinux_file_ioctl+0x46f/0x5e0 [ 54.876255] ? selinux_file_ioctl+0x125/0x5e0 [ 54.876262] ? ioctl_preallocate+0x210/0x210 [ 54.876269] ? selinux_file_mprotect+0x620/0x620 [ 54.876282] ? __sanitizer_cov_trace_cmp4+0xb/0x20 [ 54.876289] ? __fd_install+0x200/0x640 [ 54.876297] ? fd_install+0x4d/0x60 [ 54.876305] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 54.876311] ? security_file_ioctl+0x8d/0xc0 [ 54.876319] ksys_ioctl+0xab/0xd0 [ 54.876327] __x64_sys_ioctl+0x73/0xb0 [ 54.876334] do_syscall_64+0xfd/0x620 [ 54.876343] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 54.876348] RIP: 0033:0x441399 [ 54.876355] 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 [ 54.876358] RSP: 002b:00007ffe022fda78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 54.876365] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441399 [ 54.876370] RDX: 0000000020000040 RSI: 000000000000541c RDI: 0000000000000004 [ 54.876374] RBP: 000000000000d5f3 R08: 00000000004002c8 R09: 00000000004002c8 [ 54.876378] R10: 000000000000000d R11: 0000000000000246 R12: 0000000000402110 [ 54.876382] R13: 00000000004021a0 R14: 0000000000000000 R15: 0000000000000000 [ 54.877849] Kernel Offset: disabled