[ 31.752639] audit: type=1800 audit(1576237254.247:33): pid=6884 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 [ 31.781141] audit: type=1800 audit(1576237254.247:34): pid=6884 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: [ 36.187963] random: sshd: uninitialized urandom read (32 bytes read) [ 36.586664] audit: type=1400 audit(1576237259.077:35): avc: denied { map } for pid=7058 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 [ 36.639366] random: sshd: uninitialized urandom read (32 bytes read) [ 37.248018] random: sshd: uninitialized urandom read (32 bytes read) [ 37.433966] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.194' (ECDSA) to the list of known hosts. [ 42.994704] random: sshd: uninitialized urandom read (32 bytes read) 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 [ 43.111776] audit: type=1400 audit(1576237265.607:36): avc: denied { map } for pid=7070 comm="syz-executor172" path="/root/syz-executor172675213" 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 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 [ 43.482386] ================================================================== [ 43.482417] BUG: KASAN: use-after-free in n_tty_receive_buf_common+0x1feb/0x2410 [ 43.482423] Read of size 1 at addr ffff8880a77accc1 by task syz-executor172/7152 [ 43.482426] [ 43.482435] CPU: 1 PID: 7152 Comm: syz-executor172 Not tainted 4.14.158-syzkaller #0 [ 43.482440] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.482446] Call Trace: [ 43.482455] dump_stack+0x142/0x197 [ 43.530597] ? n_tty_receive_buf_common+0x1feb/0x2410 [ 43.530607] print_address_description.cold+0x7c/0x1dc [ 43.530614] ? n_tty_receive_buf_common+0x1feb/0x2410 [ 43.530620] kasan_report.cold+0xa9/0x2af [ 43.530630] __asan_report_load1_noabort+0x14/0x20 [ 43.530638] n_tty_receive_buf_common+0x1feb/0x2410 [ 43.530660] n_tty_receive_buf2+0x34/0x40 [ 43.530669] ? n_tty_receive_buf_common+0x2410/0x2410 [ 43.530676] tty_ldisc_receive_buf+0xa5/0x1a0 [ 43.530686] paste_selection+0x1e6/0x3f2 [ 43.530696] ? find_held_lock+0x35/0x130 [ 43.530706] ? set_selection+0xe30/0xe30 [ 43.530716] ? lock_downgrade+0x740/0x740 [ 43.530724] ? wake_up_q+0xf0/0xf0 [ 43.530738] tioclinux+0x10e/0x400 [ 43.530747] vt_ioctl+0x180c/0x2170 [ 43.530756] ? avc_has_extended_perms+0x8ec/0xe40 [ 43.530765] ? complete_change_console+0x360/0x360 [ 43.530779] ? avc_ss_reset+0x110/0x110 [ 43.530792] ? do_raw_spin_unlock+0x16b/0x260 [ 43.530802] ? tty_jobctrl_ioctl+0x44/0xc10 [ 43.530811] ? _raw_spin_unlock+0x2d/0x50 [ 43.530818] ? complete_change_console+0x360/0x360 [ 43.530827] tty_ioctl+0x841/0x1320 [ 43.530837] ? tty_vhangup+0x30/0x30 [ 43.530853] ? __might_sleep+0x93/0xb0 [ 43.530860] ? save_trace+0x290/0x290 [ 43.530871] ? tty_vhangup+0x30/0x30 [ 43.530882] do_vfs_ioctl+0x7ae/0x1060 [ 43.656008] ? selinux_file_mprotect+0x5d0/0x5d0 [ 43.656020] ? ioctl_preallocate+0x1c0/0x1c0 [ 43.665186] ? lock_downgrade+0x740/0x740 [ 43.665200] ? security_file_ioctl+0x7d/0xb0 [ 43.665206] ? security_file_ioctl+0x89/0xb0 [ 43.665217] SyS_ioctl+0x8f/0xc0 [ 43.665224] ? do_vfs_ioctl+0x1060/0x1060 [ 43.665235] do_syscall_64+0x1e8/0x640 [ 43.665242] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 43.665256] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 43.665264] RIP: 0033:0x441349 [ 43.665268] RSP: 002b:00007ffef0496ef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 43.665278] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441349 [ 43.665283] RDX: 0000000020000000 RSI: 000000000000541c RDI: 0000000000000003 [ 43.665288] RBP: 000000000000a9a3 R08: 000000000000000d R09: 00000000004002c8 [ 43.665293] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004020c0 [ 43.665297] R13: 0000000000402150 R14: 0000000000000000 R15: 0000000000000000 [ 43.665312] [ 43.665317] Allocated by task 7147: [ 43.665326] save_stack_trace+0x16/0x20 [ 43.665333] save_stack+0x45/0xd0 [ 43.665338] kasan_kmalloc+0xce/0xf0 [ 43.665343] __kmalloc+0x15d/0x7a0 [ 43.665350] set_selection+0x79a/0xe30 [ 43.665356] tioclinux+0xf7/0x400 [ 43.665361] vt_ioctl+0x180c/0x2170 [ 43.665367] tty_ioctl+0x841/0x1320 [ 43.665374] do_vfs_ioctl+0x7ae/0x1060 [ 43.665379] SyS_ioctl+0x8f/0xc0 [ 43.665385] do_syscall_64+0x1e8/0x640 [ 43.665391] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 43.665393] [ 43.665397] Freed by task 7150: [ 43.665402] save_stack_trace+0x16/0x20 [ 43.665407] save_stack+0x45/0xd0 [ 43.665413] kasan_slab_free+0x75/0xc0 [ 43.665418] kfree+0xcc/0x270 [ 43.665423] set_selection+0x7b7/0xe30 [ 43.665428] tioclinux+0xf7/0x400 [ 43.665433] vt_ioctl+0x180c/0x2170 [ 43.665446] tty_ioctl+0x841/0x1320 [ 43.665452] do_vfs_ioctl+0x7ae/0x1060 [ 43.665458] SyS_ioctl+0x8f/0xc0 [ 43.665463] do_syscall_64+0x1e8/0x640 [ 43.665470] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 43.665472] [ 43.665477] The buggy address belongs to the object at ffff8880a77accc0 [ 43.665477] which belongs to the cache kmalloc-256 of size 256 [ 43.665482] The buggy address is located 1 bytes inside of [ 43.665482] 256-byte region [ffff8880a77accc0, ffff8880a77acdc0) [ 43.665487] The buggy address belongs to the page: [ 43.879868] page:ffffea00029deb00 count:1 mapcount:0 mapping:ffff8880a77ac040 index:0x0 [ 43.879877] flags: 0xfffe0000000100(slab) [ 43.879886] raw: 00fffe0000000100 ffff8880a77ac040 0000000000000000 000000010000000c [ 43.879892] raw: ffffea000294a2a0 ffffea0002839820 ffff8880aa8007c0 0000000000000000 [ 43.879895] page dumped because: kasan: bad access detected [ 43.879896] [ 43.879898] Memory state around the buggy address: [ 43.879904] ffff8880a77acb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 43.879909] ffff8880a77acc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 43.879914] >ffff8880a77acc80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 43.879917] ^ [ 43.879922] ffff8880a77acd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 43.879928] ffff8880a77acd80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 43.879931] ================================================================== [ 43.879934] Disabling lock debugging due to kernel taint [ 43.880182] Kernel panic - not syncing: panic_on_warn set ... [ 43.880182] [ 43.880190] CPU: 1 PID: 7152 Comm: syz-executor172 Tainted: G B 4.14.158-syzkaller #0 [ 43.880193] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.880195] Call Trace: [ 43.880205] dump_stack+0x142/0x197 [ 43.880220] ? n_tty_receive_buf_common+0x1feb/0x2410 [ 43.880227] panic+0x1f9/0x42d [ 43.880233] ? add_taint.cold+0x16/0x16 [ 43.880242] ? ___preempt_schedule+0x16/0x18 [ 43.880255] kasan_end_report+0x47/0x4f [ 43.880262] kasan_report.cold+0x130/0x2af [ 43.880269] __asan_report_load1_noabort+0x14/0x20 [ 43.880276] n_tty_receive_buf_common+0x1feb/0x2410 [ 43.880291] n_tty_receive_buf2+0x34/0x40 [ 43.880298] ? n_tty_receive_buf_common+0x2410/0x2410 [ 43.880305] tty_ldisc_receive_buf+0xa5/0x1a0 [ 43.880313] paste_selection+0x1e6/0x3f2 [ 43.880322] ? find_held_lock+0x35/0x130 [ 43.880333] ? set_selection+0xe30/0xe30 [ 43.880341] ? lock_downgrade+0x740/0x740 [ 43.880348] ? wake_up_q+0xf0/0xf0 [ 43.880370] tioclinux+0x10e/0x400 [ 43.880376] vt_ioctl+0x180c/0x2170 [ 43.880384] ? avc_has_extended_perms+0x8ec/0xe40 [ 43.880391] ? complete_change_console+0x360/0x360 [ 43.880397] ? avc_ss_reset+0x110/0x110 [ 43.880407] ? do_raw_spin_unlock+0x16b/0x260 [ 43.880414] ? tty_jobctrl_ioctl+0x44/0xc10 [ 43.880420] ? _raw_spin_unlock+0x2d/0x50 [ 43.880426] ? complete_change_console+0x360/0x360 [ 43.880433] tty_ioctl+0x841/0x1320 [ 43.880440] ? tty_vhangup+0x30/0x30 [ 43.880450] ? __might_sleep+0x93/0xb0 [ 43.880457] ? save_trace+0x290/0x290 [ 43.880467] ? tty_vhangup+0x30/0x30 [ 43.880475] do_vfs_ioctl+0x7ae/0x1060 [ 43.880483] ? selinux_file_mprotect+0x5d0/0x5d0 [ 43.880490] ? ioctl_preallocate+0x1c0/0x1c0 [ 43.880496] ? lock_downgrade+0x740/0x740 [ 43.880508] ? security_file_ioctl+0x7d/0xb0 [ 43.880514] ? security_file_ioctl+0x89/0xb0 [ 43.880521] SyS_ioctl+0x8f/0xc0 [ 43.880528] ? do_vfs_ioctl+0x1060/0x1060 [ 43.880535] do_syscall_64+0x1e8/0x640 [ 43.880541] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 43.880550] entry_SYSCALL_64_after_hwframe+0x42/0xb7 [ 43.880556] RIP: 0033:0x441349 [ 43.880561] RSP: 002b:00007ffef0496ef8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 43.880571] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441349 [ 43.880576] RDX: 0000000020000000 RSI: 000000000000541c RDI: 0000000000000003 [ 43.880580] RBP: 000000000000a9a3 R08: 000000000000000d R09: 00000000004002c8 [ 43.880585] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004020c0 [ 43.880590] R13: 0000000000402150 R14: 0000000000000000 R15: 0000000000000000 [ 43.881849] Kernel Offset: disabled [ 44.242079] Rebooting in 86400 seconds..