================================================================== BUG: KASAN: use-after-free in __dev_queue_xmit+0x33f9/0x3950 net/core/dev.c:3772 Read of size 8 at addr ffff8801c6a964c0 by task syz-executor0/9110 CPU: 0 PID: 9110 Comm: syz-executor0 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:handle_mm_fault+0x54f/0xc70 mm/memory.c:3895 Code: 40 00 4c 89 fe e8 a1 5e cb ff 4d 85 ff 0f 85 b2 04 00 00 e8 63 5d cb ff 48 8b b5 70 ff ff ff 48 89 df 44 89 f2 e8 d1 a6 ff ff <89> c3 e8 4a 5d cb ff 31 ff 44 89 ee e8 50 5e cb ff 45 85 ed 0f 85 RSP: 0018:ffff880182477740 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000200 RBX: ffff8801d3679630 RCX: 0000000000000000 RDX: 0000000000040000 RSI: ffffffff81b1bb7b RDI: ffff8801824775c8 RBP: ffff8801824777e0 R08: ffff8801d877a0c0 R09: ffffed003af90f60 R10: ffffed003af90f60 R11: ffff8801d7c87b03 R12: 1ffff1003048eeeb R13: 0000000000000000 R14: 0000000000000004 R15: 0000000000000000 faultin_page mm/gup.c:518 [inline] __get_user_pages+0x806/0x1b30 mm/gup.c:718 populate_vma_page_range+0x2db/0x3d0 mm/gup.c:1222 __mm_populate+0x286/0x4d0 mm/gup.c:1270 mm_populate include/linux/mm.h:2307 [inline] vm_mmap_pgoff+0x27f/0x2c0 mm/util.c:362 ksys_mmap_pgoff+0xf1/0x660 mm/mmap.c:1585 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline] __x64_sys_mmap+0xe9/0x1b0 arch/x86/kernel/sys_x86_64.c:91 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457579 Code: 1d 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 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f45afcf7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000457579 RDX: 0000000000000002 RSI: 0000000000b36000 RDI: 0000000020000000 RBP: 000000000072bf00 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 00007f45afcf86d4 R13: 00000000004c284a R14: 00000000004d3bd0 R15: 00000000ffffffff Allocated by task 7036: 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 8619: 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 ffff8801c6a964c0 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 0 bytes inside of 2048-byte region [ffff8801c6a964c0, ffff8801c6a96cc0) The buggy address belongs to the page: page:ffffea00071aa580 count:1 mapcount:0 mapping:ffff8801da800c40 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000010200(slab|head) raw: 02fffc0000010200 ffffea00071d6d08 ffffea0007539908 ffff8801da800c40 raw: 0000000000000000 ffff8801c6a964c0 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c6a96380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801c6a96400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801c6a96480: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8801c6a96500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c6a96580: fb fb fb fb fb fb fb fb fb fb 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