================================================================== BUG: KASAN: use-after-free in ip6_dst_idev include/net/ip6_fib.h:141 [inline] BUG: KASAN: use-after-free in ip6_xmit+0x1776/0x1a00 net/ipv6/ip6_output.c:237 Read of size 8 at addr ffff8800bba21a18 by task syz-executor3/10236 CPU: 1 PID: 10236 Comm: syz-executor3 Not tainted 4.4.141-g1b37d68 #7 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 e27c78df00d16c11 ffff8801d78ef548 ffffffff81e0e18d ffffea0002ee8840 ffff8800bba21a18 0000000000000000 ffff8800bba21a18 0000000000001200 ffff8801d78ef580 ffffffff81515a86 ffff8800bba21a18 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x124 lib/dump_stack.c:51 [] print_address_description+0x6c/0x216 mm/kasan/report.c:252 [] kasan_report_error mm/kasan/report.c:351 [inline] [] kasan_report.cold.7+0x175/0x2f7 mm/kasan/report.c:408 [] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:429 [] ip6_dst_idev include/net/ip6_fib.h:141 [inline] [] ip6_xmit+0x1776/0x1a00 net/ipv6/ip6_output.c:237 [] inet6_csk_xmit+0x245/0x490 net/ipv6/inet6_connection_sock.c:176 [] l2tp_xmit_core net/l2tp/l2tp_core.c:1084 [inline] [] l2tp_xmit_skb+0xbeb/0xeb0 net/l2tp/l2tp_core.c:1179 [] pppol2tp_sendmsg+0x4e0/0x7d0 net/l2tp/l2tp_ppp.c:355 [] sock_sendmsg_nosec net/socket.c:625 [inline] [] sock_sendmsg+0xcc/0x110 net/socket.c:635 [] ___sys_sendmsg+0x441/0x880 net/socket.c:1962 [] __sys_sendmmsg+0x1d4/0x2e0 net/socket.c:2040 [] C_SYSC_sendmmsg net/compat.c:728 [inline] [] compat_SyS_sendmmsg+0x32/0x40 net/compat.c:725 [] do_syscall_32_irqs_on arch/x86/entry/common.c:393 [inline] [] do_fast_syscall_32+0x326/0x8b0 arch/x86/entry/common.c:460 [] sysenter_flags_fixed+0xd/0x17 Allocated by task 8771: [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:616 [] kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:554 [] slab_post_alloc_hook mm/slub.c:1349 [inline] [] slab_alloc_node mm/slub.c:2615 [inline] [] slab_alloc mm/slub.c:2623 [inline] [] kmem_cache_alloc+0xbe/0x2a0 mm/slub.c:2628 [] dst_alloc+0xb5/0x1a0 net/core/dst.c:210 [] rt_dst_alloc+0x78/0x430 net/ipv4/route.c:1478 [] __mkroute_output net/ipv4/route.c:2132 [inline] [] __ip_route_output_key_hash+0x9ac/0x2380 net/ipv4/route.c:2344 [] icmp_route_lookup+0x43f/0xd70 net/ipv4/icmp.c:485 [] icmp_send+0x909/0x13d0 net/ipv4/icmp.c:706 [] __udp4_lib_rcv+0xf21/0x23e0 net/ipv4/udp.c:1850 [] udp_rcv+0x21/0x30 net/ipv4/udp.c:2043 [] ip_local_deliver_finish+0x257/0xa60 net/ipv4/ip_input.c:216 [] NF_HOOK_THRESH include/linux/netfilter.h:226 [inline] [] NF_HOOK include/linux/netfilter.h:249 [inline] [] ip_local_deliver+0x1f1/0x380 net/ipv4/ip_input.c:257 [] dst_input include/net/dst.h:504 [inline] [] ip_rcv_finish+0x65a/0x1640 net/ipv4/ip_input.c:365 [] NF_HOOK_THRESH include/linux/netfilter.h:226 [inline] [] NF_HOOK include/linux/netfilter.h:249 [inline] [] ip_rcv+0x9e4/0x1190 net/ipv4/ip_input.c:455 [] __netif_receive_skb_core+0x12d6/0x2940 net/core/dev.c:4019 [] __netif_receive_skb+0x5b/0x1b0 net/core/dev.c:4054 [] process_backlog+0x216/0x6a0 net/core/dev.c:4647 [] napi_poll net/core/dev.c:4885 [inline] [] net_rx_action+0x3a2/0xdb0 net/core/dev.c:4950 [] __do_softirq+0x22c/0xa1a kernel/softirq.c:273 Freed by task 3902: [] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63 [] save_stack+0x43/0xd0 mm/kasan/kasan.c:512 [] set_track mm/kasan/kasan.c:524 [inline] [] kasan_slab_free+0x72/0xc0 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] [] kmem_cache_free+0xbe/0x340 mm/slub.c:2881 [] dst_destroy.part.6+0x1f5/0x330 net/core/dst.c:270 [] dst_destroy+0x15/0x20 net/core/dst.c:252 [] dst_free include/net/dst.h:425 [inline] [] dst_rcu_free+0x9c/0xc0 include/net/dst.h:435 [] __rcu_reclaim kernel/rcu/rcu.h:118 [inline] [] rcu_do_batch kernel/rcu/tree.c:2705 [inline] [] invoke_rcu_callbacks kernel/rcu/tree.c:2973 [inline] [] __rcu_process_callbacks kernel/rcu/tree.c:2940 [inline] [] rcu_process_callbacks+0x927/0x1440 kernel/rcu/tree.c:2957 [] __do_softirq+0x22c/0xa1a kernel/softirq.c:273 The buggy address belongs to the object at ffff8800bba21a00 which belongs to the cache ip_dst_cache of size 208 The buggy address is located 24 bytes inside of 208-byte region [ffff8800bba21a00, ffff8800bba21ad0) The buggy address belongs to the page: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 10222 at kernel/locking/lockdep.c:973 lock_accessed kernel/locking/lockdep.c:973 [inline]() WARNING: CPU: 0 PID: 10222 at kernel/locking/lockdep.c:973 __bfs+0x2aa/0x5f0 kernel/locking/lockdep.c:1040()