================================================================== BUG: KASAN: slab-out-of-bounds in __ipv6_addr_type+0x26c/0x290 net/ipv6/addrconf_core.c:68 Read of size 4 at addr ffff8801d6e7d938 by task syz-executor.4/16265 CPU: 0 PID: 16265 Comm: syz-executor.4 Not tainted 4.4.174+ #4 0000000000000000 5915c7c7d51431c9 ffff88010b89eda0 ffffffff81aad1a1 0000000000000000 ffffea00075b9f00 ffff8801d6e7d938 0000000000000004 ffff8801d6e7d680 ffff88010b89edd8 ffffffff81490120 0000000000000000 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [] print_address_description+0x6f/0x21b mm/kasan/report.c:252 [] kasan_report_error mm/kasan/report.c:351 [inline] [] kasan_report mm/kasan/report.c:408 [inline] [] kasan_report.cold+0x8c/0x2be mm/kasan/report.c:393 [] __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:428 [] __ipv6_addr_type+0x26c/0x290 net/ipv6/addrconf_core.c:68 [] ipv6_addr_type include/net/ipv6.h:330 [inline] [] ip6_tnl_xmit2+0x2ac/0x2320 net/ipv6/ip6_tunnel.c:988 [] ip4ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1134 [inline] [] ip6_tnl_xmit+0xa09/0xe00 net/ipv6/ip6_tunnel.c:1212 [] __netdev_start_xmit include/linux/netdevice.h:3750 [inline] [] netdev_start_xmit include/linux/netdevice.h:3759 [inline] [] xmit_one net/core/dev.c:2781 [inline] [] dev_hard_start_xmit+0x7c1/0x11e0 net/core/dev.c:2797 [] __dev_queue_xmit+0x164b/0x1bb0 net/core/dev.c:3229 [] dev_queue_xmit+0x18/0x20 net/core/dev.c:3263 [] neigh_direct_output+0x16/0x20 net/core/neighbour.c:1369 [] dst_neigh_output include/net/dst.h:461 [inline] [] ip_finish_output2+0x6a2/0x1280 net/ipv4/ip_output.c:213 [] ip_finish_output+0x8b2/0xc60 net/ipv4/ip_output.c:288 [] NF_HOOK_COND include/linux/netfilter.h:240 [inline] [] ip_output+0x227/0x4c0 net/ipv4/ip_output.c:362 [] dst_output include/net/dst.h:498 [inline] [] ip_local_out+0x9c/0x180 net/ipv4/ip_output.c:119 [] ip_send_skb+0x3e/0xc0 net/ipv4/ip_output.c:1453 [] udp_send_skb+0x4fd/0xc70 net/ipv4/udp.c:842 [] udp_sendmsg+0x16cf/0x1c60 net/ipv4/udp.c:1072 [] udpv6_sendmsg+0x12f2/0x24f0 net/ipv6/udp.c:1173 [] inet_sendmsg+0x202/0x4d0 net/ipv4/af_inet.c:755 [] sock_sendmsg_nosec net/socket.c:638 [inline] [] sock_sendmsg+0xbe/0x110 net/socket.c:648 [] ___sys_sendmsg+0x769/0x890 net/socket.c:1975 [] __sys_sendmsg+0xc5/0x160 net/socket.c:2009 [] SYSC_sendmsg net/socket.c:2020 [inline] [] SyS_sendmsg+0x2d/0x50 net/socket.c:2016 [] entry_SYSCALL_64_fastpath+0x1e/0x9a Allocated by task 16265: [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack mm/kasan/kasan.c:512 [inline] [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_kmalloc.part.0+0x62/0xf0 mm/kasan/kasan.c:616 [] kasan_kmalloc+0xb7/0xd0 mm/kasan/kasan.c:601 [] __kmalloc+0x141/0x330 mm/slub.c:3613 [] kmalloc include/linux/slab.h:481 [inline] [] kzalloc include/linux/slab.h:620 [inline] [] neigh_alloc net/core/neighbour.c:285 [inline] [] __neigh_create+0x1d6/0x1b30 net/core/neighbour.c:457 [] neigh_create include/net/neighbour.h:313 [inline] [] ipv4_neigh_lookup+0x52e/0x6e0 net/ipv4/route.c:464 [] dst_neigh_lookup include/net/dst.h:466 [inline] [] ip6_tnl_xmit2+0x27b/0x2320 net/ipv6/ip6_tunnel.c:982 [] ip4ip6_tnl_xmit net/ipv6/ip6_tunnel.c:1134 [inline] [] ip6_tnl_xmit+0xa09/0xe00 net/ipv6/ip6_tunnel.c:1212 [] __netdev_start_xmit include/linux/netdevice.h:3750 [inline] [] netdev_start_xmit include/linux/netdevice.h:3759 [inline] [] xmit_one net/core/dev.c:2781 [inline] [] dev_hard_start_xmit+0x7c1/0x11e0 net/core/dev.c:2797 [] __dev_queue_xmit+0x164b/0x1bb0 net/core/dev.c:3229 [] dev_queue_xmit+0x18/0x20 net/core/dev.c:3263 [] neigh_direct_output+0x16/0x20 net/core/neighbour.c:1369 [] dst_neigh_output include/net/dst.h:461 [inline] [] ip_finish_output2+0x6a2/0x1280 net/ipv4/ip_output.c:213 [] ip_finish_output+0x8b2/0xc60 net/ipv4/ip_output.c:288 [] NF_HOOK_COND include/linux/netfilter.h:240 [inline] [] ip_output+0x227/0x4c0 net/ipv4/ip_output.c:362 [] dst_output include/net/dst.h:498 [inline] [] ip_local_out+0x9c/0x180 net/ipv4/ip_output.c:119 [] ip_send_skb+0x3e/0xc0 net/ipv4/ip_output.c:1453 [] udp_send_skb+0x4fd/0xc70 net/ipv4/udp.c:842 [] udp_sendmsg+0x16cf/0x1c60 net/ipv4/udp.c:1072 [] udpv6_sendmsg+0x12f2/0x24f0 net/ipv6/udp.c:1173 [] inet_sendmsg+0x202/0x4d0 net/ipv4/af_inet.c:755 [] sock_sendmsg_nosec net/socket.c:638 [inline] [] sock_sendmsg+0xbe/0x110 net/socket.c:648 [] ___sys_sendmsg+0x769/0x890 net/socket.c:1975 [] __sys_sendmsg+0xc5/0x160 net/socket.c:2009 [] SYSC_sendmsg net/socket.c:2020 [inline] [] SyS_sendmsg+0x2d/0x50 net/socket.c:2016 [] entry_SYSCALL_64_fastpath+0x1e/0x9a Freed by task 6887: [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack mm/kasan/kasan.c:512 [inline] [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_slab_free+0xb0/0x190 mm/kasan/kasan.c:589 [] slab_free_hook mm/slub.c:1383 [inline] [] slab_free_freelist_hook mm/slub.c:1405 [inline] [] slab_free mm/slub.c:2859 [inline] [] kfree+0xf4/0x310 mm/slub.c:3749 [] free_pipe_info+0x218/0x2d0 fs/pipe.c:657 [] put_pipe_info+0xb3/0xd0 fs/pipe.c:548 [] pipe_release+0x1b6/0x250 fs/pipe.c:569 [] __fput+0x246/0x710 fs/file_table.c:208 [] ____fput+0x16/0x20 fs/file_table.c:244 [] task_work_run+0x202/0x2b0 kernel/task_work.c:115 [] tracehook_notify_resume include/linux/tracehook.h:191 [inline] [] exit_to_usermode_loop+0x14a/0x170 arch/x86/entry/common.c:188 [] prepare_exit_to_usermode arch/x86/entry/common.c:221 [inline] [] syscall_return_slowpath+0x25b/0x2e0 arch/x86/entry/common.c:286 [] int_ret_from_sys_call+0x25/0xa3 The buggy address belongs to the object at ffff8801d6e7d680 which belongs to the cache kmalloc-1024 of size 1024 The buggy address is located 696 bytes inside of 1024-byte region [ffff8801d6e7d680, ffff8801d6e7da80) The buggy address belongs to the page: double fault: 0000 [#1] PREEMPT SMP KASAN Modules linked in: CPU: 0 PID: 16265 Comm: syz-executor.4 Not tainted 4.4.174+ #4 task: ffff880045d80000 task.stack: ffff88010b898000 RIP: 0010:[] [] dump_page_badflags+0x4/0x70 mm/debug.c:84 RSP: 0018:ffff880100000000 EFLAGS: 00010046 RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc9000435e000 RDX: 0000000000000000 RSI: ffffffff82891be0 RDI: ffffea00075b9f00 RBP: ffff880100000000 R08: 0000000000000026 R09: 0000000000000000 R10: 0000000000000001 R11: ffffffff83fdf174 R12: ffffea00075b9f00 R13: ffffffff82891be0 R14: ffff8801d6e7da80 R15: ffff8801d6e7d680 FS: 00007f1465885700(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff8800fffffff8 CR3: 00000001146ef000 CR4: 00000000001606b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: Call Trace: Code: e8 3e 48 69 c0 80 06 00 00 f0 48 ff 80 a8 1b 19 83 5b 5d c3 48 89 df e8 0b a3 05 00 eb dd 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 <41> 57 41 56 41 55 49 89 f5 41 54 49 89 fc 53 48 89 d3 48 83 ec RIP [] dump_page_badflags+0x4/0x70 mm/debug.c:84 RSP ---[ end trace 95004cd76a2276f2 ]---