================================================================== BUG: KASAN: slab-out-of-bounds in ip6_dst_lookup_tail+0x196a/0x1b30 net/ipv6/ip6_output.c:1063 Read of size 8 at addr ffff888081d31bff by task syz-executor.1/17298 CPU: 1 PID: 17298 Comm: syz-executor.1 Not tainted 5.2.0-rc1+ #8 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:188 __kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 kasan_report+0x12/0x20 mm/kasan/common.c:614 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:132 ip6_dst_lookup_tail+0x196a/0x1b30 net/ipv6/ip6_output.c:1063 ip6_dst_lookup_flow+0xa8/0x220 net/ipv6/ip6_output.c:1147 inet6_csk_route_socket+0x85d/0xf40 net/ipv6/inet6_connection_sock.c:110 inet6_csk_xmit+0x110/0x5d0 net/ipv6/inet6_connection_sock.c:125 l2tp_xmit_core net/l2tp/l2tp_core.c:1033 [inline] l2tp_xmit_skb+0x1112/0x13e0 net/l2tp/l2tp_core.c:1135 pppol2tp_sendmsg+0x4a2/0x6b0 net/l2tp/l2tp_ppp.c:329 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:671 ___sys_sendmsg+0x3e2/0x920 net/socket.c:2292 __sys_sendmmsg+0x1bf/0x4d0 net/socket.c:2387 __do_sys_sendmmsg net/socket.c:2416 [inline] __se_sys_sendmmsg net/socket.c:2413 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2413 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459279 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fac85576c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459279 RDX: 0800000000000198 RSI: 0000000020005fc0 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fac855776d4 R13: 00000000004c65fc R14: 00000000004db280 R15: 00000000ffffffff Allocated by task 2991: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:497 slab_post_alloc_hook mm/slab.h:437 [inline] slab_alloc mm/slab.c:3326 [inline] kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3488 dst_alloc+0x10e/0x200 net/core/dst.c:93 ip6_dst_alloc+0x34/0xa0 net/ipv6/route.c:356 ip6_rt_pcpu_alloc net/ipv6/route.c:1257 [inline] rt6_make_pcpu_route net/ipv6/route.c:1287 [inline] ip6_pol_route+0x656/0x1050 net/ipv6/route.c:2031 ip6_pol_route_input+0x65/0x80 net/ipv6/route.c:2047 fib6_rule_lookup+0x133/0x5a0 net/ipv6/fib6_rules.c:116 ip6_route_input_lookup+0xb7/0xd0 net/ipv6/route.c:2059 ip6_route_input+0x5e2/0x9e0 net/ipv6/route.c:2194 ip6_rcv_finish_core.isra.0+0x174/0x590 net/ipv6/ip6_input.c:67 ip6_rcv_finish+0x17a/0x310 net/ipv6/ip6_input.c:78 ip_sabotage_in net/bridge/br_netfilter_hooks.c:837 [inline] ip_sabotage_in+0x20d/0x280 net/bridge/br_netfilter_hooks.c:828 nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline] nf_hook_slow+0xbc/0x1e0 net/netfilter/core.c:512 nf_hook include/linux/netfilter.h:260 [inline] NF_HOOK include/linux/netfilter.h:303 [inline] ipv6_rcv+0x25d/0x420 net/ipv6/ip6_input.c:276 __netif_receive_skb_one_core+0x113/0x1a0 net/core/dev.c:4990 __netif_receive_skb+0x2c/0x1d0 net/core/dev.c:5104 netif_receive_skb_internal+0x117/0x5c0 net/core/dev.c:5207 netif_receive_skb+0x6e/0x5a0 net/core/dev.c:5282 br_netif_receive_skb+0x107/0x200 net/bridge/br_input.c:33 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] br_pass_frame_up+0x35a/0x730 net/bridge/br_input.c:68 br_handle_frame_finish+0x6f4/0x14e0 net/bridge/br_input.c:174 br_nf_hook_thresh+0x2e9/0x370 net/bridge/br_netfilter_hooks.c:1006 br_nf_pre_routing_finish_ipv6+0x6fa/0xdb0 net/bridge/br_netfilter_ipv6.c:210 NF_HOOK include/linux/netfilter.h:305 [inline] br_nf_pre_routing_ipv6+0x437/0x810 net/bridge/br_netfilter_ipv6.c:240 br_nf_pre_routing+0xf2e/0x14b0 net/bridge/br_netfilter_hooks.c:482 nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline] nf_hook_bridge_pre net/bridge/br_input.c:229 [inline] br_handle_frame+0x806/0x1350 net/bridge/br_input.c:354 __netif_receive_skb_core+0xa8e/0x3060 net/core/dev.c:4919 __netif_receive_skb_one_core+0xa8/0x1a0 net/core/dev.c:4988 __netif_receive_skb+0x2c/0x1d0 net/core/dev.c:5104 process_backlog+0x206/0x750 net/core/dev.c:5944 napi_poll net/core/dev.c:6367 [inline] net_rx_action+0x4f5/0x1070 net/core/dev.c:6433 __do_softirq+0x25c/0x94c kernel/softirq.c:293 Freed by task 9: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3432 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3698 dst_destroy+0x29e/0x3c0 net/core/dst.c:129 dst_destroy_rcu+0x16/0x19 net/core/dst.c:142 __rcu_reclaim kernel/rcu/rcu.h:222 [inline] rcu_do_batch kernel/rcu/tree.c:2092 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2310 [inline] rcu_core+0xba5/0x1500 kernel/rcu/tree.c:2291 __do_softirq+0x25c/0x94c kernel/softirq.c:293 The buggy address belongs to the object at ffff888081d31ac0 which belongs to the cache ip6_dst_cache of size 224 The buggy address is located 95 bytes to the right of 224-byte region [ffff888081d31ac0, ffff888081d31ba0) The buggy address belongs to the page: page:ffffea0002074c40 refcount:1 mapcount:0 mapping:ffff88809bea5380 index:0xffff888081d31e80 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea00027f9388 ffffea0002678248 ffff88809bea5380 raw: ffff888081d31e80 ffff888081d310c0 0000000100000007 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888081d31a80: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ffff888081d31b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888081d31b80: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888081d31c00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888081d31c80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ==================================================================