================================================================== 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 ffff8801d37f7298 by task syz-executor2/6177 CPU: 1 PID: 6177 Comm: syz-executor2 Not tainted 4.4.140-ged9bdc8 #4 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 0000000000000000 7905aca41134e259 ffff8800a372f548 ffffffff81e0e08d ffffea00074dfdc0 ffff8801d37f7298 0000000000000000 ffff8801d37f7298 0000000000001200 ffff8800a372f580 ffffffff81515a56[ 71.070696] SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket ffff8801d37f7298 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:392 [inline] [] do_fast_syscall_32+0x326/0x8b0 arch/x86/entry/common.c:459 [] sysenter_flags_fixed+0xd/0x17 Allocated by task 6131: [] 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 [] ip_route_input_slow net/ipv4/route.c:1926 [inline] [] ip_route_input_noref+0x1a59/0x3890 net/ipv4/route.c:2027 [] ip_rcv_finish+0x1df/0x1640 net/ipv4/ip_input.c:336 [] 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 3873: [] 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 net/core/dst.c:252 [inline] [] dst_destroy_rcu+0x15/0x40 net/core/dst.c:295 [] __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 ffff8801d37f7280 which belongs to the cache ip_dst_cache of size 208 The buggy address is located 24 bytes inside of 208-byte region [ffff8801d37f7280, ffff8801d37f7350) The buggy address belongs to the page: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 6167 at lib/list_debug.c:62 __list_del_entry+0x162/0x1c0 lib/list_debug.c:60() list_del corruption. next->prev should be ffff8801d73ac140, but was (null)