[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 28.756634] kauditd_printk_skb: 7 callbacks suppressed [ 28.756645] audit: type=1800 audit(1544467488.562:29): pid=5926 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 28.790560] audit: type=1800 audit(1544467488.562:30): pid=5926 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0 Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 32.067860] sshd (6064) used greatest stack depth: 15600 bytes left Warning: Permanently added '10.128.0.177' (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 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 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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 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 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 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 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 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 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 55.071820] ================================================================== [ 55.079410] BUG: KASAN: use-after-free in ___neigh_create+0x21fd/0x2600 [ 55.086166] Read of size 8 at addr ffff8881b3566b70 by task syz-executor075/6593 [ 55.093693] [ 55.095322] CPU: 1 PID: 6593 Comm: syz-executor075 Not tainted 4.20.0-rc6-next-20181210+ #164 [ 55.103964] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 55.113302] Call Trace: [ 55.115884] dump_stack+0x244/0x39d [ 55.119525] ? dump_stack_print_info.cold.1+0x20/0x20 [ 55.124713] ? printk+0xa7/0xcf [ 55.127986] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 55.132733] print_address_description.cold.4+0x9/0x1ff [ 55.138097] ? ___neigh_create+0x21fd/0x2600 [ 55.142505] kasan_report.cold.5+0x1b/0x39 [ 55.146738] ? ___neigh_create+0x21fd/0x2600 [ 55.151136] ? ___neigh_create+0x21fd/0x2600 [ 55.155547] __asan_report_load8_noabort+0x14/0x20 [ 55.160472] ___neigh_create+0x21fd/0x2600 [ 55.164734] ? neigh_remove_one+0x5a0/0x5a0 [ 55.169048] ? mark_held_locks+0x130/0x130 [ 55.173274] ? find_held_lock+0x36/0x1c0 [ 55.177323] ? mark_held_locks+0xc7/0x130 [ 55.181464] ? __local_bh_enable_ip+0x160/0x260 [ 55.186128] ? lockdep_hardirqs_on+0x3bb/0x5b0 [ 55.190739] ? trace_hardirqs_on+0xbd/0x310 [ 55.195054] ? neigh_lookup+0x586/0x7c0 [ 55.199088] ? trace_hardirqs_off_caller+0x310/0x310 [ 55.204212] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 55.209763] ? check_preemption_disabled+0x48/0x280 [ 55.214917] ? neigh_lookup+0x553/0x7c0 [ 55.218879] ? neigh_lookup+0x553/0x7c0 [ 55.222860] ? __local_bh_enable_ip+0x160/0x260 [ 55.227570] ? neigh_lookup+0x586/0x7c0 [ 55.231542] ? arp_hash+0xa0/0xa0 [ 55.235126] ? neigh_seq_start+0x770/0x770 [ 55.239362] ? refcount_sub_and_test_checked+0x203/0x310 [ 55.244805] ? find_held_lock+0x36/0x1c0 [ 55.248856] __neigh_create+0x30/0x40 [ 55.252672] arp_req_set+0x59d/0xaa0 [ 55.256389] ? arp_req_delete+0x870/0x870 [ 55.260522] ? apparmor_cred_prepare+0x5a0/0x5a0 [ 55.265355] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 55.270905] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 55.276430] ? full_name_hash+0xb8/0x110 [ 55.280477] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 55.286003] arp_ioctl+0x48b/0xae0 [ 55.289546] ? arp_constructor+0xd80/0xd80 [ 55.293900] inet_ioctl+0x237/0x360 [ 55.297518] ? lock_acquire+0x1ed/0x520 [ 55.301495] ? inet_stream_connect+0xa0/0xa0 [ 55.306047] ? mark_held_locks+0x130/0x130 [ 55.310271] ? mark_held_locks+0x130/0x130 [ 55.314498] ? rwlock_bug.part.2+0x90/0x90 [ 55.318721] ? debug_mutex_init+0x2d/0x60 [ 55.322861] sock_do_ioctl+0xeb/0x420 [ 55.326654] ? compat_ifr_data_ioctl+0x170/0x170 [ 55.331472] ? vmf_insert_mixed_mkwrite+0x40/0x40 [ 55.336324] ? find_held_lock+0x36/0x1c0 [ 55.340512] ? graph_lock+0x270/0x270 [ 55.344365] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 55.349564] sock_ioctl+0x313/0x690 [ 55.353178] ? dlci_ioctl_set+0x40/0x40 [ 55.357149] ? find_held_lock+0x36/0x1c0 [ 55.361211] ? __do_page_fault+0x62e/0xd70 [ 55.365434] ? dlci_ioctl_set+0x40/0x40 [ 55.369406] do_vfs_ioctl+0x1de/0x1790 [ 55.373281] ? rcu_dynticks_curr_cpu_in_eqs+0xa2/0x170 [ 55.378565] ? ioctl_preallocate+0x300/0x300 [ 55.382970] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 55.388498] ? __fget_light+0x2e9/0x430 [ 55.392463] ? fget_raw+0x20/0x20 [ 55.395913] ? kasan_check_write+0x14/0x20 [ 55.400134] ? up_read+0x225/0x2c0 [ 55.403818] ? do_syscall_64+0x9a/0x820 [ 55.407810] ? do_syscall_64+0x9a/0x820 [ 55.411774] ? lockdep_hardirqs_on+0x3bb/0x5b0 [ 55.416343] ? security_file_ioctl+0x94/0xc0 [ 55.420781] ksys_ioctl+0xa9/0xd0 [ 55.424223] __x64_sys_ioctl+0x73/0xb0 [ 55.428099] do_syscall_64+0x1b9/0x820 [ 55.431974] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 55.437431] ? syscall_return_slowpath+0x5e0/0x5e0 [ 55.442471] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 55.447326] ? trace_hardirqs_on_caller+0x310/0x310 [ 55.452344] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 55.457363] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 55.462921] ? prepare_exit_to_usermode+0x291/0x3b0 [ 55.467943] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 55.472777] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 55.477952] RIP: 0033:0x440e39 [ 55.481134] Code: e8 cc ab 02 00 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 bb 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 55.500150] RSP: 002b:00007ffea8160338 EFLAGS: 00000213 ORIG_RAX: 0000000000000010 [ 55.507844] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000440e39 [ 55.515198] RDX: 0000000020000000 RSI: 0000000000008955 RDI: 0000000000000003 [ 55.522532] RBP: 0000000000000000 R08: 00000000004002c8 R09: 00000000004002c8 [ 55.529805] R10: 0000000001fe3880 R11: 0000000000000213 R12: 000000000000d704 [ 55.537071] R13: 0000000000401e10 R14: 0000000000000000 R15: 0000000000000000 [ 55.544364] [ 55.545983] Allocated by task 6083: [ 55.549603] save_stack+0x43/0xd0 [ 55.553044] kasan_kmalloc+0xcb/0xd0 [ 55.556940] __kmalloc+0x15d/0x760 [ 55.560474] ___neigh_create+0x13fc/0x2600 [ 55.564843] __neigh_create+0x30/0x40 [ 55.568637] arp_req_set+0x59d/0xaa0 [ 55.572338] arp_ioctl+0x48b/0xae0 [ 55.575875] inet_ioctl+0x237/0x360 [ 55.579821] sock_do_ioctl+0xeb/0x420 [ 55.583600] sock_ioctl+0x313/0x690 [ 55.587212] do_vfs_ioctl+0x1de/0x1790 [ 55.591082] ksys_ioctl+0xa9/0xd0 [ 55.594552] __x64_sys_ioctl+0x73/0xb0 [ 55.598427] do_syscall_64+0x1b9/0x820 [ 55.602299] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 55.607467] [ 55.609076] Freed by task 0: [ 55.612212] save_stack+0x43/0xd0 [ 55.615681] __kasan_slab_free+0x102/0x150 [ 55.619951] kasan_slab_free+0xe/0x10 [ 55.623737] kfree+0xcf/0x230 [ 55.626826] rcu_process_callbacks+0xd91/0x15f0 [ 55.631480] __do_softirq+0x308/0xb7e [ 55.635257] [ 55.636867] The buggy address belongs to the object at ffff8881b3566900 [ 55.636867] which belongs to the cache kmalloc-1k of size 1024 [ 55.649524] The buggy address is located 624 bytes inside of [ 55.649524] 1024-byte region [ffff8881b3566900, ffff8881b3566d00) [ 55.661476] The buggy address belongs to the page: [ 55.666463] page:ffffea0006cd5980 count:1 mapcount:0 mapping:ffff8881da800ac0 index:0x0 compound_mapcount: 0 [ 55.676440] flags: 0x2fffc0000010200(slab|head) [ 55.681105] raw: 02fffc0000010200 ffffea0007354b88 ffffea000704b308 ffff8881da800ac0 [ 55.688986] raw: 0000000000000000 ffff8881b3566000 0000000100000007 0000000000000000 [ 55.697280] page dumped because: kasan: bad access detected [ 55.702977] [ 55.704584] Memory state around the buggy address: [ 55.709499] ffff8881b3566a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 55.716849] ffff8881b3566a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 55.724307] >ffff8881b3566b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 55.731721] ^ [ 55.738725] ffff8881b3566b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 55.746070] ffff8881b3566c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 55.753412] ================================================================== [ 55.760752] Disabling lock debugging due to kernel taint [ 55.766304] Kernel panic - not syncing: panic_on_warn set ... [ 55.772183] CPU: 1 PID: 6593 Comm: syz-executor075 Tainted: G B 4.20.0-rc6-next-20181210+ #164 [ 55.782219] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 55.791728] Call Trace: [ 55.794316] dump_stack+0x244/0x39d [ 55.797949] ? dump_stack_print_info.cold.1+0x20/0x20 [ 55.803131] ? ___neigh_create+0x2150/0x2600 [ 55.807526] panic+0x2ad/0x632 [ 55.810705] ? add_taint.cold.5+0x16/0x16 [ 55.814930] ? trace_hardirqs_on+0x9a/0x310 [ 55.819248] ? trace_hardirqs_on+0xb4/0x310 [ 55.823551] ? trace_hardirqs_on+0xb4/0x310 [ 55.828210] ? ___neigh_create+0x21fd/0x2600 [ 55.832604] end_report+0x47/0x4f [ 55.836039] kasan_report.cold.5+0xe/0x39 [ 55.840171] ? ___neigh_create+0x21fd/0x2600 [ 55.844567] ? ___neigh_create+0x21fd/0x2600 [ 55.848963] __asan_report_load8_noabort+0x14/0x20 [ 55.853879] ___neigh_create+0x21fd/0x2600 [ 55.858120] ? neigh_remove_one+0x5a0/0x5a0 [ 55.862429] ? mark_held_locks+0x130/0x130 [ 55.866652] ? find_held_lock+0x36/0x1c0 [ 55.870700] ? mark_held_locks+0xc7/0x130 [ 55.874839] ? __local_bh_enable_ip+0x160/0x260 [ 55.879496] ? lockdep_hardirqs_on+0x3bb/0x5b0 [ 55.884064] ? trace_hardirqs_on+0xbd/0x310 [ 55.888453] ? neigh_lookup+0x586/0x7c0 [ 55.892471] ? trace_hardirqs_off_caller+0x310/0x310 [ 55.897571] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 55.903102] ? check_preemption_disabled+0x48/0x280 [ 55.908108] ? neigh_lookup+0x553/0x7c0 [ 55.912070] ? neigh_lookup+0x553/0x7c0 [ 55.916036] ? __local_bh_enable_ip+0x160/0x260 [ 55.920692] ? neigh_lookup+0x586/0x7c0 [ 55.924653] ? arp_hash+0xa0/0xa0 [ 55.928091] ? neigh_seq_start+0x770/0x770 [ 55.932310] ? refcount_sub_and_test_checked+0x203/0x310 [ 55.937753] ? find_held_lock+0x36/0x1c0 [ 55.941806] __neigh_create+0x30/0x40 [ 55.945592] arp_req_set+0x59d/0xaa0 [ 55.949300] ? arp_req_delete+0x870/0x870 [ 55.953438] ? apparmor_cred_prepare+0x5a0/0x5a0 [ 55.958182] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 55.963721] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 55.969263] ? full_name_hash+0xb8/0x110 [ 55.973317] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 55.978849] arp_ioctl+0x48b/0xae0 [ 55.982380] ? arp_constructor+0xd80/0xd80 [ 55.986608] inet_ioctl+0x237/0x360 [ 55.990224] ? lock_acquire+0x1ed/0x520 [ 55.994182] ? inet_stream_connect+0xa0/0xa0 [ 55.998666] ? mark_held_locks+0x130/0x130 [ 56.003000] ? mark_held_locks+0x130/0x130 [ 56.007223] ? rwlock_bug.part.2+0x90/0x90 [ 56.011451] ? debug_mutex_init+0x2d/0x60 [ 56.015587] sock_do_ioctl+0xeb/0x420 [ 56.019387] ? compat_ifr_data_ioctl+0x170/0x170 [ 56.024135] ? vmf_insert_mixed_mkwrite+0x40/0x40 [ 56.028969] ? find_held_lock+0x36/0x1c0 [ 56.033025] ? graph_lock+0x270/0x270 [ 56.036821] ? __sanitizer_cov_trace_switch+0x53/0x90 [ 56.041995] sock_ioctl+0x313/0x690 [ 56.045603] ? dlci_ioctl_set+0x40/0x40 [ 56.049562] ? find_held_lock+0x36/0x1c0 [ 56.053609] ? __do_page_fault+0x62e/0xd70 [ 56.057830] ? dlci_ioctl_set+0x40/0x40 [ 56.061789] do_vfs_ioctl+0x1de/0x1790 [ 56.065661] ? rcu_dynticks_curr_cpu_in_eqs+0xa2/0x170 [ 56.070943] ? ioctl_preallocate+0x300/0x300 [ 56.075341] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 56.080862] ? __fget_light+0x2e9/0x430 [ 56.084825] ? fget_raw+0x20/0x20 [ 56.088266] ? kasan_check_write+0x14/0x20 [ 56.092553] ? up_read+0x225/0x2c0 [ 56.096085] ? do_syscall_64+0x9a/0x820 [ 56.100041] ? do_syscall_64+0x9a/0x820 [ 56.104089] ? lockdep_hardirqs_on+0x3bb/0x5b0 [ 56.108657] ? security_file_ioctl+0x94/0xc0 [ 56.113050] ksys_ioctl+0xa9/0xd0 [ 56.116488] __x64_sys_ioctl+0x73/0xb0 [ 56.120381] do_syscall_64+0x1b9/0x820 [ 56.124253] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 56.129605] ? syscall_return_slowpath+0x5e0/0x5e0 [ 56.134520] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 56.139348] ? trace_hardirqs_on_caller+0x310/0x310 [ 56.144347] ? prepare_exit_to_usermode+0x3b0/0x3b0 [ 56.149419] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 56.154990] ? prepare_exit_to_usermode+0x291/0x3b0 [ 56.159997] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 56.164825] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 56.170144] RIP: 0033:0x440e39 [ 56.173323] Code: e8 cc ab 02 00 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 bb 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 56.192212] RSP: 002b:00007ffea8160338 EFLAGS: 00000213 ORIG_RAX: 0000000000000010 [ 56.199974] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000440e39 [ 56.207234] RDX: 0000000020000000 RSI: 0000000000008955 RDI: 0000000000000003 [ 56.214488] RBP: 0000000000000000 R08: 00000000004002c8 R09: 00000000004002c8 [ 56.221743] R10: 0000000001fe3880 R11: 0000000000000213 R12: 000000000000d704 [ 56.229010] R13: 0000000000401e10 R14: 0000000000000000 R15: 0000000000000000 [ 56.237136] Kernel Offset: disabled [ 56.240763] Rebooting in 86400 seconds..