[....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.836464] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 21.602171] random: sshd: uninitialized urandom read (32 bytes read) [ 22.070669] random: sshd: uninitialized urandom read (32 bytes read) [ 22.904274] random: sshd: uninitialized urandom read (32 bytes read) [ 23.042846] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.50' (ECDSA) to the list of known hosts. [ 28.470564] random: sshd: uninitialized urandom read (32 bytes read) net.ipv6.conf.syz_tun.accept_dad = 0 net.ipv6.conf.syz_tun.router_solicitations = 0 [ 28.559403] IPVS: Creating netns size=2536 id=1 RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported Error: argument "bridge0" is wrong: Device does not exist Error: argument "bridge0" is wrong: Device does not exist Error: argument "bond0" is wrong: Device does not exist Error: argument "bond0" is wrong: Device does not exist [ 28.675215] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 28.687459] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready Error: argument "team0" is wrong: Device does not exist Error: argument "team0" is wrong: Device does not exist [ 28.730145] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bond: link is not ready [ 28.741063] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bond: link is not ready RTNETLINK answers: Operation not supported [ 28.783018] IPv6: ADDRCONF(NETDEV_UP): veth0_to_team: link is not ready [ 28.794938] IPv6: ADDRCONF(NETDEV_UP): veth1_to_team: link is not ready [ 28.806464] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 28.819031] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready Cannot find device "bridge0" Cannot find device "bridge0" Cannot find device "bridge0" Cannot find device "bridge0" Cannot find device "vcan0" Cannot find device "vcan0" Cannot find device "vcan0" Cannot find device "vcan0" RTNETLINK answers: Operation not supported Cannot find device "gre0" Cannot find device "gre0" Cannot find device "gre0" Cannot find device "gre0" Cannot find device "gretap0" Cannot find device "gretap0" Cannot find device "gretap0" Cannot find device "gretap0" Cannot find device "ip_vti0" Cannot find device "ip_vti0" Cannot find device "ip_vti0" Cannot find device "ip_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6_vti0" Cannot find device "ip6tnl0" Cannot find device "ip6tnl0" Cannot find device "ip6tnl0" Cannot find device "ip6tnl0" Cannot find device "ip6gre0" Cannot find device "ip6gre0" Cannot find device "ip6gre0" Cannot find device "ip6gre0" Cannot find device "ip6gretap0" Cannot find device "ip6gretap0" Cannot find device "ip6gretap0" Cannot find device "ip6gretap0" Cannot find device "erspan0" Cannot find device "erspan0" Cannot find device "erspan0" Cannot find device "erspan0" Cannot find device "bond0" Cannot find device "bond0" Cannot find device "bond0" Cannot find device "bond0" Cannot find device "team0" Cannot find device "team0" Cannot find device "team0" Cannot find device "team0" [ 29.276574] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 29.299726] IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready [ 29.305994] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 29.312675] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready executing program [ 29.488400] protocol 0000 is buggy, dev sit0 [ 29.493136] ================================================================== [ 29.500499] BUG: KASAN: use-after-free in copy_to_iter+0x239/0x10e0 [ 29.506879] Read of size 12 at addr ffff8801b6435700 by task syz-executor396/4175 [ 29.514477] [ 29.516081] CPU: 0 PID: 4175 Comm: syz-executor396 Not tainted 4.9.99-g74fa0af4 #24 [ 29.523849] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.533183] ffff8801d72ff760 ffffffff81eb0f09 ffffea0006d90d00 ffff8801b6435700 [ 29.541172] 0000000000000000 ffff8801b6435700 ffff8801b6435700 ffff8801d72ff798 [ 29.549153] ffffffff815652eb ffff8801b6435700 000000000000000c 0000000000000000 [ 29.557142] Call Trace: [ 29.559704] [] dump_stack+0xc1/0x128 [ 29.565041] [] print_address_description+0x6c/0x234 [ 29.571675] [] kasan_report.cold.6+0x242/0x2fe [ 29.577889] [] ? copy_to_iter+0x239/0x10e0 [ 29.583746] [] check_memory_region+0x14f/0x1b0 [ 29.589950] [] kasan_check_read+0x11/0x20 [ 29.595719] [] copy_to_iter+0x239/0x10e0 [ 29.601401] [] ? iov_iter_get_pages+0xd60/0xd60 [ 29.607690] [] ? check_preemption_disabled+0x3b/0x170 [ 29.614504] [] skb_copy_datagram_iter+0x1d1/0x8f0 [ 29.620969] [] ? sock_has_perm+0x1c2/0x3e0 [ 29.626827] [] packet_recvmsg+0x263/0xf40 [ 29.632596] [] ? packet_rcv_has_room+0xa0/0xa0 [ 29.638802] [] ? avc_has_perm+0x27d/0x4f0 [ 29.644571] [] ? selinux_socket_recvmsg+0x3f/0x50 [ 29.651049] [] ? security_socket_recvmsg+0x97/0xc0 [ 29.657600] [] ? packet_rcv_has_room+0xa0/0xa0 [ 29.663803] [] sock_recvmsg+0xc6/0x110 [ 29.669313] [] sock_read_iter+0x24a/0x360 [ 29.675082] [] ? sock_recvmsg+0x110/0x110 [ 29.680852] [] ? fsnotify+0x114/0x1100 [ 29.686362] [] ? iov_iter_init+0xaf/0x1d0 [ 29.692133] [] __vfs_read+0x3dd/0x570 [ 29.697555] [] ? do_iter_readv_writev+0x4b0/0x4b0 [ 29.704018] [] ? __fsnotify_update_child_dentry_flags.part.1+0x300/0x300 [ 29.712486] [] ? fsnotify+0x1100/0x1100 [ 29.718082] [] ? selinux_file_permission+0x82/0x470 [ 29.724718] [] ? rw_verify_area+0xe5/0x2b0 [ 29.730571] [] vfs_read+0x120/0x380 [ 29.735819] [] SyS_read+0xd9/0x1c0 [ 29.740979] [] ? vfs_copy_file_range+0x850/0x850 [ 29.747357] [] ? do_syscall_64+0x48/0x490 [ 29.753134] [] ? vfs_copy_file_range+0x850/0x850 [ 29.759512] [] do_syscall_64+0x1a6/0x490 [ 29.765194] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 29.772107] [ 29.773711] Allocated by task 4176: [ 29.777313] save_stack_trace+0x16/0x20 [ 29.781276] save_stack+0x43/0xd0 [ 29.784701] kasan_kmalloc+0xc7/0xe0 [ 29.788386] kasan_slab_alloc+0x12/0x20 [ 29.792333] __kmalloc_track_caller+0xdc/0x2b0 [ 29.796888] __kmalloc_reserve.isra.37+0x33/0xc0 [ 29.801613] __alloc_skb+0x11a/0x600 [ 29.805298] alloc_skb_with_frags+0xaf/0x520 [ 29.809676] sock_alloc_send_pskb+0x5a9/0x750 [ 29.814143] packet_sendmsg+0x1581/0x4470 [ 29.818264] sock_sendmsg+0xcc/0x110 [ 29.821948] SYSC_sendto+0x21c/0x370 [ 29.825632] SyS_sendto+0x40/0x50 [ 29.829056] do_syscall_64+0x1a6/0x490 [ 29.832913] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 29.837983] [ 29.839581] Freed by task 4176: [ 29.842830] save_stack_trace+0x16/0x20 [ 29.846776] save_stack+0x43/0xd0 [ 29.850204] kasan_slab_free+0x72/0xc0 [ 29.854063] kfree+0xfb/0x310 [ 29.857141] skb_free_head+0x8b/0xb0 [ 29.860825] skb_release_data+0x329/0x400 [ 29.864942] skb_release_all+0x4a/0x60 [ 29.868799] __kfree_skb+0x15/0x20 [ 29.872310] kfree_skb+0xcc/0x340 [ 29.875735] sit_tunnel_xmit+0xfb/0x2590 [ 29.879765] dev_hard_start_xmit+0x197/0x8b0 [ 29.884142] __dev_queue_xmit+0x19a5/0x2080 [ 29.888434] dev_queue_xmit+0x17/0x20 [ 29.892212] packet_sendmsg+0x1eff/0x4470 [ 29.896331] sock_sendmsg+0xcc/0x110 [ 29.900038] SYSC_sendto+0x21c/0x370 [ 29.903733] SyS_sendto+0x40/0x50 [ 29.907157] do_syscall_64+0x1a6/0x490 [ 29.911015] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 29.916085] [ 29.917684] The buggy address belongs to the object at ffff8801b6435680 [ 29.917684] which belongs to the cache kmalloc-512 of size 512 [ 29.930399] The buggy address is located 128 bytes inside of [ 29.930399] 512-byte region [ffff8801b6435680, ffff8801b6435880) [ 29.942852] The buggy address belongs to the page: [ 29.947757] page:ffffea0006d90d00 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 [ 29.957931] flags: 0x8000000000004080(slab|head) [ 29.962653] page dumped because: kasan: bad access detected [ 29.968343] [ 29.969959] Memory state around the buggy address: [ 29.974860] ffff8801b6435600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 29.982201] ffff8801b6435680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.989532] >ffff8801b6435700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 29.996860] ^ [ 30.000200] ffff8801b6435780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.007529] ffff8801b6435800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 30.014859] ================================================================== [ 30.022190] Disabling lock debugging due to kernel taint [ 30.028413] Kernel panic - not syncing: panic_on_warn set ... [ 30.028413] [ 30.035781] CPU: 0 PID: 4175 Comm: syz-executor396 Tainted: G B 4.9.99-g74fa0af4 #24 [ 30.044762] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.054090] ffff8801d72ff6c0 ffffffff81eb0f09 ffffffff843c5065 00000000ffffffff [ 30.062083] 0000000000000000 0000000000000000 ffff8801b6435700 ffff8801d72ff780 [ 30.070068] ffffffff8141f855 0000000041b58ab3 ffffffff843b8768 ffffffff8141f696 [ 30.078068] Call Trace: [ 30.080628] [] dump_stack+0xc1/0x128 [ 30.085964] [] panic+0x1bf/0x3bc [ 30.090952] [] ? add_taint.cold.6+0x16/0x16 [ 30.096896] [] ? ___preempt_schedule+0x16/0x18 [ 30.103097] [] kasan_end_report+0x47/0x4f [ 30.108866] [] kasan_report.cold.6+0x76/0x2fe [ 30.114983] [] ? copy_to_iter+0x239/0x10e0 [ 30.120840] [] check_memory_region+0x14f/0x1b0 [ 30.127052] [] kasan_check_read+0x11/0x20 [ 30.132824] [] copy_to_iter+0x239/0x10e0 [ 30.138508] [] ? iov_iter_get_pages+0xd60/0xd60 [ 30.144798] [] ? check_preemption_disabled+0x3b/0x170 [ 30.151620] [] skb_copy_datagram_iter+0x1d1/0x8f0 [ 30.158085] [] ? sock_has_perm+0x1c2/0x3e0 [ 30.163941] [] packet_recvmsg+0x263/0xf40 [ 30.169713] [] ? packet_rcv_has_room+0xa0/0xa0 [ 30.175915] [] ? avc_has_perm+0x27d/0x4f0 [ 30.181685] [] ? selinux_socket_recvmsg+0x3f/0x50 [ 30.188147] [] ? security_socket_recvmsg+0x97/0xc0 [ 30.194700] [] ? packet_rcv_has_room+0xa0/0xa0 [ 30.200902] [] sock_recvmsg+0xc6/0x110 [ 30.206420] [] sock_read_iter+0x24a/0x360 [ 30.212188] [] ? sock_recvmsg+0x110/0x110 [ 30.217957] [] ? fsnotify+0x114/0x1100 [ 30.223466] [] ? iov_iter_init+0xaf/0x1d0 [ 30.229252] [] __vfs_read+0x3dd/0x570 [ 30.234675] [] ? do_iter_readv_writev+0x4b0/0x4b0 [ 30.241146] [] ? __fsnotify_update_child_dentry_flags.part.1+0x300/0x300 [ 30.249605] [] ? fsnotify+0x1100/0x1100 [ 30.255206] [] ? selinux_file_permission+0x82/0x470 [ 30.261843] [] ? rw_verify_area+0xe5/0x2b0 [ 30.267698] [] vfs_read+0x120/0x380 [ 30.272946] [] SyS_read+0xd9/0x1c0 [ 30.278108] [] ? vfs_copy_file_range+0x850/0x850 [ 30.284486] [] ? do_syscall_64+0x48/0x490 [ 30.290267] [] ? vfs_copy_file_range+0x850/0x850 [ 30.296643] [] do_syscall_64+0x1a6/0x490 [ 30.302329] [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 30.309725] Dumping ftrace buffer: [ 30.313238] (ftrace buffer empty) [ 30.316920] Kernel Offset: disabled [ 30.320519] Rebooting in 86400 seconds..