================================================================== BUG: KASAN: slab-out-of-bounds in ip6_dst_lookup_tail+0x196a/0x1b30 net/ipv6/ip6_output.c:1071 Read of size 8 at addr ffff88809350ccff by task syz-executor.0/19325 CPU: 1 PID: 19325 Comm: syz-executor.0 Not tainted 5.2.0-rc2+ #9 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:1071 ip6_dst_lookup_flow+0xa8/0x220 net/ipv6/ip6_output.c:1155 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:00007f3c354b7c78 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: 00007f3c354b86d4 R13: 00000000004c65fc R14: 00000000004db280 R15: 00000000ffffffff Allocated by task 12838: 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+0x649/0x1010 net/ipv6/route.c:2031 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2204 fib6_rule_lookup+0x133/0x5a0 net/ipv6/fib6_rules.c:116 ip6_route_output_flags+0x2c4/0x350 net/ipv6/route.c:2233 ip6_route_output include/net/ip6_route.h:89 [inline] ip6_dst_lookup_tail+0xd10/0x1b30 net/ipv6/ip6_output.c:1027 ip6_dst_lookup_flow+0xa8/0x220 net/ipv6/ip6_output.c:1155 sctp_v6_get_dst+0x785/0x1d80 net/sctp/ipv6.c:278 sctp_transport_route+0x12d/0x360 net/sctp/transport.c:297 sctp_assoc_add_peer+0x53e/0xfc0 net/sctp/associola.c:663 sctp_process_param net/sctp/sm_make_chunk.c:2531 [inline] sctp_process_init+0x2491/0x2b10 net/sctp/sm_make_chunk.c:2344 sctp_cmd_process_init net/sctp/sm_sideeffect.c:667 [inline] sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1369 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1179 [inline] sctp_do_sm+0x3a30/0x50e0 net/sctp/sm_sideeffect.c:1150 sctp_assoc_bh_rcv+0x343/0x660 net/sctp/associola.c:1059 sctp_inq_push+0x1e4/0x280 net/sctp/inqueue.c:80 sctp_backlog_rcv+0x196/0xbe0 net/sctp/input.c:339 sk_backlog_rcv include/net/sock.h:950 [inline] __release_sock+0x129/0x390 net/core/sock.c:2418 release_sock+0x59/0x1c0 net/core/sock.c:2934 sctp_wait_for_connect+0x316/0x540 net/sctp/socket.c:9039 __sctp_connect+0xab2/0xcd0 net/sctp/socket.c:1226 sctp_connect net/sctp/socket.c:4846 [inline] sctp_inet_connect+0x29c/0x340 net/sctp/socket.c:4862 __sys_connect+0x264/0x330 net/socket.c:1840 __do_sys_connect net/socket.c:1851 [inline] __se_sys_connect net/socket.c:1848 [inline] __x64_sys_connect+0x73/0xb0 net/socket.c:1848 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 11778: 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 ffff88809350cbc0 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 [ffff88809350cbc0, ffff88809350cca0) The buggy address belongs to the page: page:ffffea00024d4300 refcount:1 mapcount:0 mapping:ffff888216f390c0 index:0xffff88809350ca80 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea00028f2548 ffffea00024b4c08 ffff888216f390c0 raw: ffff88809350ca80 ffff88809350c080 0000000100000004 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809350cb80: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ffff88809350cc00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88809350cc80: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88809350cd00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88809350cd80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc ==================================================================