nf_conntrack: default automatic helper assignment has been turned off for security reasons and CT-based firewall rule not found. Use the iptables CT target to attach helpers instead. ================================================================== BUG: KASAN: use-after-free in sock_net_uid include/net/sock.h:1733 [inline] BUG: KASAN: use-after-free in ip6_route_me_harder+0x9d8/0xc00 net/ipv6/netfilter.c:26 Read of size 4 at addr ffff8801ce3a91b0 by task syz-executor4/30460 CPU: 0 PID: 30460 Comm: syz-executor4 Not tainted 4.16.0-rc2+ #250 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report+0x23b/0x360 mm/kasan/report.c:412 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432 sock_net_uid include/net/sock.h:1733 [inline] ip6_route_me_harder+0x9d8/0xc00 net/ipv6/netfilter.c:26 nf_nat_ipv6_local_fn+0x2a4/0x5d0 net/ipv6/netfilter/nf_nat_l3proto_ipv6.c:414 ip6table_nat_local_fn+0x2c/0x40 net/ipv6/netfilter/ip6table_nat.c:69 nf_hook_entry_hookfn include/linux/netfilter.h:120 [inline] nf_hook_slow+0xba/0x1a0 net/netfilter/core.c:483 nf_hook include/linux/netfilter.h:243 [inline] NF_HOOK include/linux/netfilter.h:286 [inline] ip6_xmit+0x10ec/0x2260 net/ipv6/ip6_output.c:277 tcp_v6_send_synack+0x57b/0xaa0 net/ipv6/tcp_ipv6.c:490 tcp_conn_request+0x26fd/0x3660 net/ipv4/tcp_input.c:6335 tcp_v6_conn_request+0x212/0x270 net/ipv6/tcp_ipv6.c:1021 tcp_rcv_state_process+0x92a/0x4760 net/ipv4/tcp_input.c:5842 tcp_v6_do_rcv+0x739/0x1250 net/ipv6/tcp_ipv6.c:1331 tcp_v6_rcv+0x25a0/0x2d40 net/ipv6/tcp_ipv6.c:1521 ip6_input_finish+0x37e/0x17a0 net/ipv6/ip6_input.c:284 NF_HOOK include/linux/netfilter.h:288 [inline] ip6_input+0xdb/0x560 net/ipv6/ip6_input.c:327 dst_input include/net/dst.h:449 [inline] ip6_rcv_finish+0x297/0x8c0 net/ipv6/ip6_input.c:71 NF_HOOK include/linux/netfilter.h:288 [inline] ipv6_rcv+0xf37/0x1fa0 net/ipv6/ip6_input.c:208 __netif_receive_skb_core+0x1a41/0x3460 net/core/dev.c:4554 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4619 netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4693 netif_receive_skb+0xae/0x390 net/core/dev.c:4717 tun_rx_batched.isra.52+0x5ee/0x870 drivers/net/tun.c:1556 tun_get_user+0x25a5/0x3810 drivers/net/tun.c:1957 tun_chr_write_iter+0xbd/0x1c0 drivers/net/tun.c:1985 call_write_iter include/linux/fs.h:1781 [inline] do_iter_readv_writev+0x55c/0x830 fs/read_write.c:653 do_iter_write+0x154/0x540 fs/read_write.c:932 vfs_writev+0x18a/0x340 fs/read_write.c:977 do_writev+0xfc/0x2a0 fs/read_write.c:1012 SYSC_writev fs/read_write.c:1085 [inline] SyS_writev+0x27/0x30 fs/read_write.c:1082 do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x453c41 RSP: 002b:00007f7ab20a5ba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 000000000000004a RCX: 0000000000453c41 RDX: 0000000000000001 RSI: 00007f7ab20a5bf0 RDI: 00000000000000fc RBP: 0000000020000100 R08: 00000000000000fc R09: 0000000000000000 R10: 000000000000004a R11: 0000000000000293 R12: 00000000ffffffff R13: 0000000000000627 R14: 00000000006f9448 R15: 0000000000000000 Allocated by task 29798: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:552 kmem_cache_alloc_trace+0x136/0x740 mm/slab.c:3607 kmalloc include/linux/slab.h:512 [inline] kzalloc include/linux/slab.h:701 [inline] get_undo_list ipc/sem.c:1744 [inline] copy_semundo+0x19f/0x320 ipc/sem.c:2166 copy_process.part.38+0x1d5d/0x4b60 kernel/fork.c:1778 copy_process kernel/fork.c:1606 [inline] _do_fork+0x1f7/0xf70 kernel/fork.c:2087 SYSC_clone kernel/fork.c:2194 [inline] SyS_clone+0x37/0x50 kernel/fork.c:2188 do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Freed by task 29834: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:520 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:527 __cache_free mm/slab.c:3485 [inline] kfree+0xd9/0x260 mm/slab.c:3800 exit_sem+0x993/0x1e40 ipc/sem.c:2301 do_exit+0x984/0x1ad0 kernel/exit.c:858 do_group_exit+0x149/0x400 kernel/exit.c:968 get_signal+0x73a/0x16d0 kernel/signal.c:2469 do_signal+0x90/0x1e90 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0x258/0x2f0 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:265 [inline] do_syscall_64+0x6e5/0x940 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 The buggy address belongs to the object at ffff8801ce3a9180 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 48 bytes inside of 96-byte region [ffff8801ce3a9180, ffff8801ce3a91e0) The buggy address belongs to the page: page:ffffea000738ea40 count:1 mapcount:0 mapping:ffff8801ce3a9000 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801ce3a9000 0000000000000000 0000000100000020 raw: ffffea0007111ba0 ffffea0007366c60 ffff8801dac004c0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801ce3a9080: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8801ce3a9100: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff8801ce3a9180: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff8801ce3a9200: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8801ce3a9280: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================