netlink: 8 bytes leftover after parsing attributes in process `syz-executor3'. ================================================================== device team0 entered promiscuous mode BUG: KASAN: use-after-free in __dev_queue_xmit+0x33f9/0x3950 net/core/dev.c:3772 Read of size 8 at addr ffff8801c12a3380 by task ksoftirqd/0/9 audit: type=1804 audit(1538281953.082:39): pid=9577 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor0" name="/root/syzkaller-testdir349180779/syzkaller.RFG8N5/63/file0" dev="sda1" ino=16547 res=1 CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 4.19.0-rc5-next-20180928+ #84 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+0x1d3/0x2c4 lib/dump_stack.c:113 device team_slave_0 entered promiscuous mode print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 __dev_queue_xmit+0x33f9/0x3950 net/core/dev.c:3772 dev_queue_xmit+0x17/0x20 net/core/dev.c:3838 neigh_hh_output include/net/neighbour.h:473 [inline] neigh_output include/net/neighbour.h:481 [inline] ip6_finish_output2+0x1342/0x27a0 net/ipv6/ip6_output.c:120 ip6_finish_output+0x4de/0xbc0 net/ipv6/ip6_output.c:154 NF_HOOK_COND include/linux/netfilter.h:276 [inline] ip6_output+0x23e/0x9f0 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:444 [inline] NF_HOOK include/linux/netfilter.h:287 [inline] ndisc_send_skb+0x1005/0x1570 net/ipv6/ndisc.c:491 ndisc_send_rs+0x134/0x6e0 net/ipv6/ndisc.c:685 addrconf_rs_timer+0x314/0x690 net/ipv6/addrconf.c:3820 call_timer_fn+0x26d/0x920 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers+0x7e0/0xc60 kernel/time/timer.c:1682 run_timer_softirq+0x52/0xb0 kernel/time/timer.c:1695 __do_softirq+0x30b/0xb03 kernel/softirq.c:292 run_ksoftirqd+0x94/0x100 kernel/softirq.c:654 smpboot_thread_fn+0x68b/0xa00 kernel/smpboot.c:164 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Allocated by task 6825: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 __do_kmalloc_node mm/slab.c:3682 [inline] __kmalloc_node+0x47/0x70 mm/slab.c:3689 kmalloc_node include/linux/slab.h:589 [inline] kzalloc_node include/linux/slab.h:752 [inline] qdisc_alloc+0x10f/0xb50 net/sched/sch_generic.c:820 qdisc_create_dflt+0x7a/0x1e0 net/sched/sch_generic.c:894 attach_one_default_qdisc net/sched/sch_generic.c:1041 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2117 [inline] attach_default_qdiscs net/sched/sch_generic.c:1060 [inline] dev_activate+0x82f/0xcb0 net/sched/sch_generic.c:1103 __dev_open+0x2cb/0x410 net/core/dev.c:1400 __dev_change_flags+0x730/0x9b0 net/core/dev.c:7448 dev_change_flags+0x89/0x150 net/core/dev.c:7517 do_setlink+0xb5f/0x3f20 net/core/rtnetlink.c:2441 rtnl_newlink+0x136f/0x1d40 net/core/rtnetlink.c:3054 rtnetlink_rcv_msg+0x46a/0xc20 net/core/rtnetlink.c:4730 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2447 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4748 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x5a5/0x760 net/netlink/af_netlink.c:1336 netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:632 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2117 __sys_sendmsg+0x11d/0x280 net/socket.c:2155 __do_sys_sendmsg net/socket.c:2164 [inline] __se_sys_sendmsg net/socket.c:2162 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2162 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 5902: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xcf/0x230 mm/slab.c:3813 qdisc_free+0x89/0x100 net/sched/sch_generic.c:941 qdisc_free_cb+0x19/0x20 net/sched/sch_generic.c:948 __rcu_reclaim kernel/rcu/rcu.h:240 [inline] rcu_do_batch kernel/rcu/tree.c:2437 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2716 [inline] rcu_process_callbacks+0xff9/0x1ad0 kernel/rcu/tree.c:2697 __do_softirq+0x30b/0xb03 kernel/softirq.c:292 The buggy address belongs to the object at ffff8801c12a3380 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 0 bytes inside of 2048-byte region [ffff8801c12a3380, ffff8801c12a3b80) The buggy address belongs to the page: page:ffffea000704a880 count:1 mapcount:0 mapping:ffff8801da800c40 index:0xffff8801c12a2b00 compound_mapcount: 0 flags: 0x2fffc0000010200(slab|head) raw: 02fffc0000010200 ffffea00070cfc08 ffffea000706f108 ffff8801da800c40 raw: ffff8801c12a2b00 ffff8801c12a2280 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c12a3280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c12a3300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801c12a3380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801c12a3400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c12a3480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================