[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 13.704592] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 23.904389] random: sshd: uninitialized urandom read (32 bytes read) [ 24.182392] random: sshd: uninitialized urandom read (32 bytes read) [ 24.587767] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.12' (ECDSA) to the list of known hosts. [ 30.326526] urandom_read: 1 callbacks suppressed [ 30.326530] random: sshd: uninitialized urandom read (32 bytes read) 2018/08/22 20:50:56 parsed 1 programs [ 31.761664] random: cc1: uninitialized urandom read (8 bytes read) 2018/08/22 20:50:59 executed programs: 0 [ 33.345353] IPVS: Creating netns size=2536 id=1 [ 33.470143] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 33.482232] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready [ 33.525674] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bond: link is not ready [ 33.537332] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready [ 33.581742] IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready [ 33.593156] IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready [ 33.605115] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 33.618145] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready [ 34.143018] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 34.168185] IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready [ 34.174444] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 34.181497] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 34.411087] hrtimer: interrupt took 11237 ns [ 34.551519] l2tp_core: tunl 4: sockfd_lookup(fd=6) returned -9 [ 34.584242] ================================================================== [ 34.591692] BUG: KASAN: use-after-free in inet_shutdown+0x2dc/0x360 [ 34.598221] Read of size 4 at addr ffff8801bf269540 by task syz-executor0/4312 [ 34.605672] [ 34.607277] CPU: 0 PID: 4312 Comm: syz-executor0 Not tainted 4.9.123-g8dd3fc2 #79 [ 34.614871] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 34.624199] ffff8801d9827b90 ffffffff81eb9689 ffffea0006fc9a00 ffff8801bf269540 [ 34.632212] 0000000000000000 ffff8801bf269540 ffff8801d4eb0058 ffff8801d9827bc8 [ 34.640206] ffffffff8156c3fe ffff8801bf269540 0000000000000004 0000000000000000 [ 34.648210] Call Trace: [ 34.650776] [] dump_stack+0xc1/0x128 [ 34.656118] [] print_address_description+0x6c/0x234 [ 34.662762] [] kasan_report.cold.6+0x242/0x2fe [ 34.669163] [] ? inet_shutdown+0x2dc/0x360 [ 34.675085] [] __asan_report_load4_noabort+0x14/0x20 [ 34.681819] [] inet_shutdown+0x2dc/0x360 [ 34.687514] [] ? pppol2tp_recvmsg+0x280/0x280 [ 34.693626] [] pppol2tp_session_close+0xa0/0xe0 [ 34.699916] [] l2tp_tunnel_closeall+0x231/0x350 [ 34.706210] [] ? udp_v6_flush_pending_frames+0xe0/0xe0 [ 34.713108] [] ? sock_release+0x1c0/0x1c0 [ 34.718876] [] l2tp_udp_encap_destroy+0x87/0xe0 [ 34.725167] [] ? l2tp_tunnel_destruct+0x590/0x590 [ 34.731628] [] udpv6_destroy_sock+0xb1/0xd0 [ 34.737582] [] sk_common_release+0x6d/0x300 [ 34.743527] [] udp_lib_close+0x15/0x20 [ 34.749036] [] inet_release+0xff/0x1d0 [ 34.754547] [] inet6_release+0x50/0x70 [ 34.760055] [] sock_release+0x96/0x1c0 [ 34.765562] [] sock_close+0x16/0x20 [ 34.770812] [] __fput+0x263/0x700 [ 34.775885] [] ____fput+0x15/0x20 [ 34.780966] [] task_work_run+0x10c/0x180 [ 34.786655] [] exit_to_usermode_loop+0xfc/0x120 [ 34.792945] [] do_syscall_64+0x364/0x490 [ 34.798637] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 34.805539] [ 34.807140] Allocated by task 4313: [ 34.810742] save_stack_trace+0x16/0x20 [ 34.814689] save_stack+0x43/0xd0 [ 34.818114] kasan_kmalloc+0xc7/0xe0 [ 34.821800] kasan_slab_alloc+0x12/0x20 [ 34.825750] kmem_cache_alloc+0xbe/0x290 [ 34.829785] sock_alloc_inode+0x1d/0x260 [ 34.833817] alloc_inode+0x63/0x180 [ 34.837417] new_inode_pseudo+0x17/0xe0 [ 34.841411] sock_alloc+0x41/0x280 [ 34.844930] __sock_create+0x8d/0x5f0 [ 34.848708] SyS_socket+0xf0/0x1b0 [ 34.852222] do_syscall_64+0x1a6/0x490 [ 34.856086] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 34.861198] [ 34.862808] Freed by task 4310: [ 34.866064] save_stack_trace+0x16/0x20 [ 34.870012] save_stack+0x43/0xd0 [ 34.873460] kasan_slab_free+0x72/0xc0 [ 34.877346] kmem_cache_free+0xbe/0x310 [ 34.881295] sock_destroy_inode+0x56/0x70 [ 34.885422] destroy_inode+0xc5/0x120 [ 34.889201] evict+0x32b/0x4f0 [ 34.892366] iput+0x371/0x900 [ 34.895444] dentry_unlink_inode+0x277/0x330 [ 34.899825] __dentry_kill+0x280/0x4c0 [ 34.903684] dput.part.29+0x5cf/0x7b0 [ 34.907456] dput+0x1f/0x30 [ 34.910361] __fput+0x42f/0x700 [ 34.913610] ____fput+0x15/0x20 [ 34.916864] task_work_run+0x10c/0x180 [ 34.920722] exit_to_usermode_loop+0xfc/0x120 [ 34.925373] do_syscall_64+0x364/0x490 [ 34.929239] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 34.934309] [ 34.935926] The buggy address belongs to the object at ffff8801bf269540 [ 34.935926] which belongs to the cache sock_inode_cache of size 960 [ 34.948990] The buggy address is located 0 bytes inside of [ 34.948990] 960-byte region [ffff8801bf269540, ffff8801bf269900) [ 34.960678] The buggy address belongs to the page: [ 34.965580] page:ffffea0006fc9a00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 34.975750] flags: 0x8000000000004080(slab|head) [ 34.980474] page dumped because: kasan: bad access detected [ 34.986150] [ 34.987753] Memory state around the buggy address: [ 34.992659] ffff8801bf269400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 34.999989] ffff8801bf269480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc [ 35.007319] >ffff8801bf269500: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb [ 35.014653] ^ [ 35.020076] ffff8801bf269580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 35.027408] ffff8801bf269600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 35.034735] ================================================================== [ 35.042062] Disabling lock debugging due to kernel taint [ 35.048361] Kernel panic - not syncing: panic_on_warn set ... [ 35.048361] [ 35.055720] CPU: 0 PID: 4312 Comm: syz-executor0 Tainted: G B 4.9.123-g8dd3fc2 #79 [ 35.064528] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 35.073857] ffff8801d9827af0 ffffffff81eb9689 ffffffff843c821b 00000000ffffffff [ 35.081876] 0000000000000000 0000000000000000 ffff8801d4eb0058 ffff8801d9827bb0 [ 35.089856] ffffffff81423f75 0000000041b58ab3 ffffffff843bb878 ffffffff81423db6 [ 35.097861] Call Trace: [ 35.100552] [] dump_stack+0xc1/0x128 [ 35.105954] [] panic+0x1bf/0x3bc [ 35.110953] [] ? add_taint.cold.6+0x16/0x16 [ 35.116902] [] ? ___preempt_schedule+0x16/0x18 [ 35.123112] [] kasan_end_report+0x47/0x4f [ 35.128883] [] kasan_report.cold.6+0x76/0x2fe [ 35.135000] [] ? inet_shutdown+0x2dc/0x360 [ 35.140868] [] __asan_report_load4_noabort+0x14/0x20 [ 35.147602] [] inet_shutdown+0x2dc/0x360 [ 35.153305] [] ? pppol2tp_recvmsg+0x280/0x280 [ 35.159438] [] pppol2tp_session_close+0xa0/0xe0 [ 35.165738] [] l2tp_tunnel_closeall+0x231/0x350 [ 35.172037] [] ? udp_v6_flush_pending_frames+0xe0/0xe0 [ 35.178944] [] ? sock_release+0x1c0/0x1c0 [ 35.184721] [] l2tp_udp_encap_destroy+0x87/0xe0 [ 35.191021] [] ? l2tp_tunnel_destruct+0x590/0x590 [ 35.197493] [] udpv6_destroy_sock+0xb1/0xd0 [ 35.203446] [] sk_common_release+0x6d/0x300 [ 35.209401] [] udp_lib_close+0x15/0x20 [ 35.214982] [] inet_release+0xff/0x1d0 [ 35.220502] [] inet6_release+0x50/0x70 [ 35.226029] [] sock_release+0x96/0x1c0 [ 35.231574] [] sock_close+0x16/0x20 [ 35.236836] [] __fput+0x263/0x700 [ 35.241955] [] ____fput+0x15/0x20 [ 35.247038] [] task_work_run+0x10c/0x180 [ 35.252788] [] exit_to_usermode_loop+0xfc/0x120 [ 35.259087] [] do_syscall_64+0x364/0x490 [ 35.264776] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 35.271989] Dumping ftrace buffer: [ 35.275509] (ftrace buffer empty) [ 35.279195] Kernel Offset: disabled [ 35.282802] Rebooting in 86400 seconds..