================================================================== BUG: KASAN: slab-out-of-bounds in ip6_dst_lookup_tail+0x196a/0x1b30 net/ipv6/ip6_output.c:1010 Read of size 8 at addr ffff888095f4ed3f by task syz-executor.4/8853 CPU: 0 PID: 8853 Comm: syz-executor.4 Not tainted 5.2.0-rc1+ #4 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:1010 ip6_dst_lookup_flow+0xa8/0x220 net/ipv6/ip6_output.c:1094 sctp_v6_get_dst+0x15c1/0x1d80 net/sctp/ipv6.c:346 sctp_transport_route+0x12d/0x360 net/sctp/transport.c:312 sctp_packet_config+0xb8c/0xfd0 net/sctp/output.c:118 sctp_outq_select_transport+0x1f1/0x790 net/sctp/outqueue.c:873 sctp_outq_flush_ctrl.constprop.0+0x2c7/0xd30 net/sctp/outqueue.c:907 sctp_outq_flush+0xe8/0x2780 net/sctp/outqueue.c:1200 sctp_outq_uncork+0x6c/0x80 net/sctp/outqueue.c:772 sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1791 [inline] sctp_side_effects net/sctp/sm_sideeffect.c:1194 [inline] sctp_do_sm+0x504/0x50e0 net/sctp/sm_sideeffect.c:1165 sctp_primitive_ASSOCIATE+0x9d/0xd0 net/sctp/primitive.c:88 sctp_sendmsg_to_asoc+0xc50/0x1f10 net/sctp/socket.c:1927 sctp_sendmsg+0x109a/0x17d0 net/sctp/socket.c:2117 inet_sendmsg+0x141/0x5d0 net/ipv4/af_inet.c:802 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:00007f558ada6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459279 RDX: 0000000000000001 RSI: 0000000020e8e000 RDI: 0000000000000003 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f558ada76d4 R13: 00000000004c65fc R14: 00000000004db280 R15: 00000000ffffffff Allocated by task 866: 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 icmp6_dst_alloc+0x1a9/0x660 net/ipv6/route.c:2800 ndisc_send_skb+0xfc1/0x14a0 net/ipv6/ndisc.c:488 ndisc_send_ns+0x3a9/0x850 net/ipv6/ndisc.c:650 rt6_probe_deferred+0xe3/0x1a0 net/ipv6/route.c:543 process_one_work+0x989/0x1790 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x354/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Freed by task 6835: 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 ffff888095f4ec00 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 [ffff888095f4ec00, ffff888095f4ece0) The buggy address belongs to the page: page:ffffea000257d380 refcount:1 mapcount:0 mapping:ffff88809b6c6980 index:0xffff888095f4e840 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea00026d93c8 ffffea0002327808 ffff88809b6c6980 raw: ffff888095f4e840 ffff888095f4e0c0 0000000100000007 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888095f4ec00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888095f4ec80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff888095f4ed00: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ^ ffff888095f4ed80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888095f4ee00: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================