device lo left promiscuous mode ================================================================== BUG: KASAN: use-after-free in fib6_ifdown+0x1f8/0x220 net/ipv6/route.c:3473 Read of size 8 at addr ffff8801ce5cf380 by task syz-executor5/29322 CPU: 1 PID: 29322 Comm: syz-executor5 Not tainted 4.15.0-rc7+ #169 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=12 sclass=netlink_route_socket pig=29329 comm=syz-executor0 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x25b/0x340 mm/kasan/report.c:409 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 fib6_ifdown+0x1f8/0x220 net/ipv6/route.c:3473 fib6_clean_node+0x333/0x4f0 net/ipv6/ip6_fib.c:1914 fib6_walk_continue+0x46c/0x8a0 net/ipv6/ip6_fib.c:1840 fib6_walk+0x91/0xf0 net/ipv6/ip6_fib.c:1888 fib6_clean_tree+0x1e6/0x340 net/ipv6/ip6_fib.c:1958 __fib6_clean_all+0x1f4/0x3a0 net/ipv6/ip6_fib.c:1974 fib6_clean_all+0x27/0x30 net/ipv6/ip6_fib.c:1985 rt6_ifdown+0xd1/0x6a0 net/ipv6/route.c:3490 addrconf_ifdown+0x134/0x14d0 net/ipv6/addrconf.c:3589 addrconf_notify+0x5eb/0x2270 net/ipv6/addrconf.c:3514 notifier_call_chain+0x136/0x2c0 kernel/notifier.c:93 __raw_notifier_call_chain kernel/notifier.c:394 [inline] raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401 call_netdevice_notifiers_info+0x32/0x60 net/core/dev.c:1691 call_netdevice_notifiers net/core/dev.c:1709 [inline] __dev_notify_flags+0x262/0x430 net/core/dev.c:6869 dev_change_flags+0xf5/0x140 net/core/dev.c:6903 dev_ifsioc+0x60d/0x9b0 net/core/dev_ioctl.c:257 dev_ioctl+0x2d7/0xfb0 net/core/dev_ioctl.c:566 sock_do_ioctl+0x94/0xb0 net/socket.c:973 dev_ifsioc net/socket.c:2978 [inline] compat_sock_ioctl_trans net/socket.c:3234 [inline] compat_sock_ioctl+0xc77/0x29f0 net/socket.c:3265 C_SYSC_ioctl fs/compat_ioctl.c:1473 [inline] compat_SyS_ioctl+0x151/0x2a30 fs/compat_ioctl.c:1419 do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline] do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389 entry_SYSENTER_compat+0x54/0x63 arch/x86/entry/entry_64_compat.S:129 RIP: 0023:0xf7f58c79 RSP: 002b:00000000f771208c EFLAGS: 00000296 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000015 RCX: 0000000000008914 RDX: 0000000020171000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 27299: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3544 dst_alloc+0x11f/0x1a0 net/core/dst.c:107 __ip6_dst_alloc+0x35/0x90 net/ipv6/route.c:361 ip6_dst_alloc+0x29/0xb0 net/ipv6/route.c:376 ip6_route_info_create+0x4ff/0x2d40 net/ipv6/route.c:2537 ip6_route_add+0xa2/0x190 net/ipv6/route.c:2774 inet6_rtm_newroute+0x14f/0x160 net/ipv6/route.c:3959 rtnetlink_rcv_msg+0x733/0x1020 net/core/rtnetlink.c:4411 netlink_rcv_skb+0x224/0x470 net/netlink/af_netlink.c:2408 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4423 netlink_unicast_kernel net/netlink/af_netlink.c:1275 [inline] netlink_unicast+0x4ee/0x700 net/netlink/af_netlink.c:1301 netlink_sendmsg+0xa4a/0xe60 net/netlink/af_netlink.c:1864 sock_sendmsg_nosec net/socket.c:638 [inline] sock_sendmsg+0xca/0x110 net/socket.c:648 sock_write_iter+0x31a/0x5d0 net/socket.c:917 call_write_iter include/linux/fs.h:1772 [inline] do_iter_readv_writev+0x525/0x7f0 fs/read_write.c:653 do_iter_write+0x154/0x540 fs/read_write.c:932 compat_writev+0x225/0x420 fs/read_write.c:1246 do_compat_writev+0x115/0x220 fs/read_write.c:1267 C_SYSC_writev fs/read_write.c:1278 [inline] compat_SyS_writev+0x26/0x30 fs/read_write.c:1274 do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline] do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389 entry_SYSENTER_compat+0x54/0x63 arch/x86/entry/entry_64_compat.S:129 Freed by task 29294: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3488 [inline] kmem_cache_free+0x83/0x2a0 mm/slab.c:3746 dst_destroy+0x216/0x330 net/core/dst.c:138 dst_destroy_rcu+0x16/0x20 net/core/dst.c:151 __rcu_reclaim kernel/rcu/rcu.h:195 [inline] rcu_do_batch kernel/rcu/tree.c:2758 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:3012 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2979 [inline] rcu_process_callbacks+0xd6c/0x17f0 kernel/rcu/tree.c:2996 __do_softirq+0x2d7/0xb85 kernel/softirq.c:285 The buggy address belongs to the object at ffff8801ce5cf380 which belongs to the cache ip6_dst_cache of size 384 The buggy address is located 0 bytes inside of 384-byte region [ffff8801ce5cf380, ffff8801ce5cf500) The buggy address belongs to the page: page:ffffea00073973c0 count:1 mapcount:0 mapping:ffff8801ce5cf000 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801ce5cf000 0000000000000000 0000000100000009 raw: ffffea0006f7d820 ffffea000730e360 ffff8801d305c240 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801ce5cf280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801ce5cf300: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8801ce5cf380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801ce5cf400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801ce5cf480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================