================================================================== BUG: KASAN: use-after-free in __dev_queue_xmit+0x33f9/0x3950 net/core/dev.c:3772 Read of size 8 at addr ffff8801b94a1100 by task syz-executor5/6218 CPU: 1 PID: 6218 Comm: syz-executor5 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 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 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x17f/0x1c0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1cb/0x750 arch/x86/kernel/apic/apic.c:1061 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:804 RIP: 0010:set_pte_at arch/x86/include/asm/paravirt.h:456 [inline] RIP: 0010:copy_one_pte mm/memory.c:812 [inline] RIP: 0010:copy_pte_range mm/memory.c:855 [inline] RIP: 0010:copy_pmd_range mm/memory.c:906 [inline] RIP: 0010:copy_pud_range mm/memory.c:940 [inline] RIP: 0010:copy_p4d_range mm/memory.c:962 [inline] RIP: 0010:copy_page_range+0xf51/0x26f0 mm/memory.c:1024 Code: 83 c0 03 38 d0 7c 08 84 d2 0f 85 5b 0b 00 00 83 03 01 e8 42 f9 cb ff 48 c7 c7 50 f5 31 89 48 89 f8 48 c1 e8 03 42 80 3c 38 00 <0f> 85 7f 11 00 00 48 83 3d 21 86 80 07 00 0f 84 f0 06 00 00 e8 16 RSP: 0018:ffff88018a3b6998 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff1263eaa RBX: ffff88018a3b6e58 RCX: ffffffff81b172cf RDX: 0000000000000000 RSI: ffffffff81b16f0e RDI: ffffffff8931f550 RBP: ffff88018a3b6ec0 R08: ffff88018a3ae500 R09: fffff94000c5389e R10: fffff94000c5389e R11: ffffea000629c4f3 R12: 0000000000000000 R13: 0000000000000010 R14: 800000018a713007 R15: dffffc0000000000 dup_mmap kernel/fork.c:585 [inline] dup_mm kernel/fork.c:1318 [inline] copy_mm kernel/fork.c:1373 [inline] copy_process+0x4720/0x8780 kernel/fork.c:1917 _do_fork+0x1cb/0x11c0 kernel/fork.c:2216 __do_sys_clone kernel/fork.c:2323 [inline] __se_sys_clone kernel/fork.c:2317 [inline] __x64_sys_clone+0xbf/0x150 kernel/fork.c:2317 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455b4a Code: f7 d8 64 89 04 25 d4 02 00 00 64 4c 8b 0c 25 10 00 00 00 31 d2 4d 8d 91 d0 02 00 00 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 f5 00 00 00 85 c0 41 89 c5 0f 85 fc 00 00 RSP: 002b:00007ffc350dc420 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffc350dc420 RCX: 0000000000455b4a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffc350dc460 R08: 0000000000000001 R09: 0000000000e58940 R10: 0000000000e58c10 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 Allocated by task 6995: 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 12079: 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 ffff8801b94a1100 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 0 bytes inside of 2048-byte region [ffff8801b94a1100, ffff8801b94a1900) The buggy address belongs to the page: page:ffffea0006e52800 count:1 mapcount:0 mapping:ffff8801da800c40 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000010200(slab|head) raw: 02fffc0000010200 ffffea0007277e08 ffffea00073b6588 ffff8801da800c40 raw: 0000000000000000 ffff8801b94a0000 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801b94a1000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801b94a1080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801b94a1100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801b94a1180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801b94a1200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================