================================================================== BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:199 [inline] BUG: KASAN: use-after-free in __in6_dev_get include/net/addrconf.h:309 [inline] BUG: KASAN: use-after-free in ip6_ignore_linkdown include/net/addrconf.h:400 [inline] BUG: KASAN: use-after-free in find_match+0xb39/0xc90 net/ipv6/route.c:749 Read of size 8 at addr ffff88805b7ec320 by task kworker/1:27/2853 CPU: 1 PID: 2853 Comm: kworker/1:27 Not tainted 5.6.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: wg-kex-wg2 wg_packet_handshake_receive_worker Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 __kasan_report.cold+0x1b/0x32 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:641 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 __read_once_size include/linux/compiler.h:199 [inline] __in6_dev_get include/net/addrconf.h:309 [inline] ip6_ignore_linkdown include/net/addrconf.h:400 [inline] find_match+0xb39/0xc90 net/ipv6/route.c:749 __find_rr_leaf+0x14e/0x750 net/ipv6/route.c:837 find_rr_leaf net/ipv6/route.c:858 [inline] rt6_select net/ipv6/route.c:902 [inline] fib6_table_lookup+0x697/0xdb0 net/ipv6/route.c:2170 ip6_pol_route+0x1f6/0xa70 net/ipv6/route.c:2206 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2455 fib6_rule_lookup+0x6b0/0x7d0 net/ipv6/fib6_rules.c:118 ip6_route_output_flags_noref+0x2d6/0x360 net/ipv6/route.c:2487 ip6_route_output_flags+0x106/0x4d0 net/ipv6/route.c:2500 ip6_route_output include/net/ip6_route.h:98 [inline] ip6_dst_lookup_tail+0x104b/0x1f20 net/ipv6/ip6_output.c:1025 ip6_dst_lookup_flow+0x8c/0x1d0 net/ipv6/ip6_output.c:1153 send6+0x636/0xb20 drivers/net/wireguard/socket.c:145 wg_socket_send_skb_to_peer drivers/net/wireguard/socket.c:189 [inline] wg_socket_send_buffer_to_peer+0x21b/0x360 drivers/net/wireguard/socket.c:211 wg_packet_send_handshake_response+0x1d8/0x200 drivers/net/wireguard/send.c:103 wg_receive_handshake_packet drivers/net/wireguard/receive.c:158 [inline] wg_packet_handshake_receive_worker+0x5a2/0x710 drivers/net/wireguard/receive.c:217 process_one_work+0xa05/0x17a0 kernel/workqueue.c:2264 worker_thread+0x98/0xe40 kernel/workqueue.c:2410 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Allocated by task 10672: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:515 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:488 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529 __do_kmalloc_node mm/slab.c:3616 [inline] __kmalloc_node+0x4e/0x70 mm/slab.c:3623 kmalloc_node include/linux/slab.h:578 [inline] kvmalloc_node+0x68/0x100 mm/util.c:574 kvmalloc include/linux/mm.h:645 [inline] kvzalloc include/linux/mm.h:653 [inline] alloc_netdev_mqs+0x98/0xe40 net/core/dev.c:9797 vti6_init_net+0x244/0x810 net/ipv6/ip6_vti.c:1119 ops_init+0xb3/0x420 net/core/net_namespace.c:137 setup_net+0x2d5/0x8b0 net/core/net_namespace.c:327 copy_net_ns+0x29e/0x5a0 net/core/net_namespace.c:468 create_new_namespaces+0x403/0xb50 kernel/nsproxy.c:108 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:229 ksys_unshare+0x444/0x980 kernel/fork.c:2955 __do_sys_unshare kernel/fork.c:3023 [inline] __se_sys_unshare kernel/fork.c:3021 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3021 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 25062: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:337 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:476 kasan_slab_free+0xe/0x10 mm/kasan/common.c:485 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x2c0 mm/slab.c:3757 __netdev_name_node_alt_destroy+0x1ff/0x2a0 net/core/dev.c:322 netdev_name_node_alt_destroy+0x57/0x80 net/core/dev.c:334 rtnl_alt_ifname net/core/rtnetlink.c:3518 [inline] rtnl_linkprop.isra.0+0x575/0x6f0 net/core/rtnetlink.c:3567 rtnl_dellinkprop+0x46/0x60 net/core/rtnetlink.c:3588 rtnetlink_rcv_msg+0x45e/0xaf0 net/core/rtnetlink.c:5438 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5456 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:672 ____sys_sendmsg+0x753/0x880 net/socket.c:2343 ___sys_sendmsg+0x100/0x170 net/socket.c:2397 __sys_sendmsg+0x105/0x1d0 net/socket.c:2430 __do_sys_sendmsg net/socket.c:2439 [inline] __se_sys_sendmsg net/socket.c:2437 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2437 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88805b7ec000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 800 bytes inside of 4096-byte region [ffff88805b7ec000, ffff88805b7ed000) The buggy address belongs to the page: page:ffffea00016dfb00 refcount:1 mapcount:0 mapping:ffff8880aa402000 index:0x0 compound_mapcount: 0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea00016db488 ffffea00016dfb88 ffff8880aa402000 raw: 0000000000000000 ffff88805b7ec000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88805b7ec200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805b7ec280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805b7ec300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805b7ec380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805b7ec400: 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