================================================================== BUG: KASAN: use-after-free in rtnetlink_put_metrics+0x621/0x690 net/core/rtnetlink.c:754 Read of size 4 at addr ffff8801b0714680 by task syz-executor2/17001 CPU: 1 PID: 17001 Comm: syz-executor2 Not tainted 4.18.0-rc7+ #35 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+0x1c9/0x2b4 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432 rtnetlink_put_metrics+0x621/0x690 net/core/rtnetlink.c:754 rt6_fill_node+0x7d9/0x1540 net/ipv6/route.c:4753 inet6_rt_notify+0x161/0x2c0 net/ipv6/route.c:4985 fib6_del_route net/ipv6/ip6_fib.c:1788 [inline] fib6_del+0xf4d/0x1310 net/ipv6/ip6_fib.c:1815 fib6_clean_node+0x3ee/0x5e0 net/ipv6/ip6_fib.c:1976 fib6_walk_continue+0x4b1/0x8e0 net/ipv6/ip6_fib.c:1899 fib6_walk+0x95/0xf0 net/ipv6/ip6_fib.c:1947 fib6_clean_tree+0x1ea/0x360 net/ipv6/ip6_fib.c:2024 __fib6_clean_all+0x21c/0x420 net/ipv6/ip6_fib.c:2040 fib6_clean_all net/ipv6/ip6_fib.c:2051 [inline] fib6_run_gc+0x182/0x3d0 net/ipv6/ip6_fib.c:2107 ndisc_netdev_event+0x4ab/0x580 net/ipv6/ndisc.c:1790 notifier_call_chain+0x180/0x390 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+0x3f/0x90 net/core/dev.c:1735 call_netdevice_notifiers net/core/dev.c:1753 [inline] dev_close_many+0x447/0x8d0 net/core/dev.c:1505 rollback_registered_many+0x52b/0xef0 net/core/dev.c:7452 netlink: 'syz-executor6': attribute type 29 has an invalid length. rollback_registered+0x1e9/0x420 net/core/dev.c:7517 unregister_netdevice_queue+0x32f/0x660 net/core/dev.c:8561 mif6_delete+0x790/0xc20 net/ipv6/ip6mr.c:735 ip6_mroute_setsockopt+0x7bc/0x1d90 net/ipv6/ip6mr.c:1658 do_ipv6_setsockopt.isra.9+0x422/0x46b0 net/ipv6/ipv6_sockglue.c:163 ipv6_setsockopt+0xbd/0x170 net/ipv6/ipv6_sockglue.c:934 rawv6_setsockopt+0x59/0x140 net/ipv6/raw.c:1060 sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3040 __sys_setsockopt+0x1c5/0x3b0 net/socket.c:1912 __do_sys_setsockopt net/socket.c:1923 [inline] __se_sys_setsockopt net/socket.c:1920 [inline] __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1920 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x456a09 Code: fd b4 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 b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd313a1cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007fd313a1d6d4 RCX: 0000000000456a09 RDX: 00000000000000cb RSI: 0000000000000029 RDI: 0000000000000013 RBP: 00000000009300a0 R08: 0000000000000003 R09: 0000000000000000 R10: 0000000020114000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d3aa8 R14: 00000000004c82c7 R15: 0000000000000000 Allocated by task 15033: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kmem_cache_alloc_trace+0x152/0x780 mm/slab.c:3620 kmalloc include/linux/slab.h:513 [inline] kzalloc include/linux/slab.h:707 [inline] fib6_metric_set+0x163/0x2c0 net/ipv6/ip6_fib.c:645 fib6_add_rt2node+0xe36/0x27f0 net/ipv6/ip6_fib.c:1000 fib6_add+0xaae/0x14d0 net/ipv6/ip6_fib.c:1308 __ip6_ins_rt+0x54/0x80 net/ipv6/route.c:1163 ip6_route_add+0x6d/0xc0 net/ipv6/route.c:3171 addrconf_prefix_route.isra.48+0x51d/0x720 net/ipv6/addrconf.c:2347 inet6_addr_modify net/ipv6/addrconf.c:4627 [inline] inet6_rtm_newaddr+0x112e/0x1b50 net/ipv6/addrconf.c:4743 rtnetlink_rcv_msg+0x46e/0xc30 net/core/rtnetlink.c:4665 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2453 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4683 netlink_unicast_kernel net/netlink/af_netlink.c:1315 [inline] netlink_unicast+0x5a0/0x760 net/netlink/af_netlink.c:1341 netlink_sendmsg+0xa18/0xfd0 net/netlink/af_netlink.c:1906 sock_sendmsg_nosec net/socket.c:642 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:652 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2126 __sys_sendmsg+0x11d/0x290 net/socket.c:2164 __do_sys_sendmsg net/socket.c:2173 [inline] __se_sys_sendmsg net/socket.c:2171 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2171 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 17001: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xd9/0x260 mm/slab.c:3813 fib6_metrics_release+0x77/0x90 net/ipv6/ip6_fib.c:179 fib6_drop_pcpu_from net/ipv6/ip6_fib.c:899 [inline] fib6_purge_rt+0x5ec/0x7f0 net/ipv6/ip6_fib.c:934 fib6_del_route net/ipv6/ip6_fib.c:1784 [inline] fib6_del+0xc11/0x1310 net/ipv6/ip6_fib.c:1815 fib6_clean_node+0x3ee/0x5e0 net/ipv6/ip6_fib.c:1976 fib6_walk_continue+0x4b1/0x8e0 net/ipv6/ip6_fib.c:1899 fib6_walk+0x95/0xf0 net/ipv6/ip6_fib.c:1947 fib6_clean_tree+0x1ea/0x360 net/ipv6/ip6_fib.c:2024 __fib6_clean_all+0x21c/0x420 net/ipv6/ip6_fib.c:2040 fib6_clean_all net/ipv6/ip6_fib.c:2051 [inline] fib6_run_gc+0x182/0x3d0 net/ipv6/ip6_fib.c:2107 ndisc_netdev_event+0x4ab/0x580 net/ipv6/ndisc.c:1790 notifier_call_chain+0x180/0x390 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+0x3f/0x90 net/core/dev.c:1735 call_netdevice_notifiers net/core/dev.c:1753 [inline] dev_close_many+0x447/0x8d0 net/core/dev.c:1505 rollback_registered_many+0x52b/0xef0 net/core/dev.c:7452 rollback_registered+0x1e9/0x420 net/core/dev.c:7517 unregister_netdevice_queue+0x32f/0x660 net/core/dev.c:8561 mif6_delete+0x790/0xc20 net/ipv6/ip6mr.c:735 ip6_mroute_setsockopt+0x7bc/0x1d90 net/ipv6/ip6mr.c:1658 do_ipv6_setsockopt.isra.9+0x422/0x46b0 net/ipv6/ipv6_sockglue.c:163 ipv6_setsockopt+0xbd/0x170 net/ipv6/ipv6_sockglue.c:934 rawv6_setsockopt+0x59/0x140 net/ipv6/raw.c:1060 sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3040 __sys_setsockopt+0x1c5/0x3b0 net/socket.c:1912 __do_sys_setsockopt net/socket.c:1923 [inline] __se_sys_setsockopt net/socket.c:1920 [inline] __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1920 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801b0714680 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes inside of 96-byte region [ffff8801b0714680, ffff8801b07146e0) The buggy address belongs to the page: page:ffffea0006c1c500 count:1 mapcount:0 mapping:ffff8801dac004c0 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea00075b0248 ffffea0006cdc888 ffff8801dac004c0 raw: 0000000000000000 ffff8801b0714000 0000000100000020 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801b0714580: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8801b0714600: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff8801b0714680: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff8801b0714700: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8801b0714780: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================