================================================================== BUG: KASAN: use-after-free in __dev_queue_xmit+0x33f9/0x3950 net/core/dev.c:3772 Read of size 8 at addr ffff8801bee86440 by task syz-executor0/9013 CPU: 0 PID: 9013 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:check_kcov_mode kernel/kcov.c:67 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x1a/0x50 kernel/kcov.c:101 Code: 89 54 10 f0 4a 89 4c d8 20 4c 89 08 5d c3 66 90 55 48 89 e5 65 48 8b 04 25 40 ee 01 00 65 8b 15 6c 85 84 7e 81 e2 00 01 1f 00 <48> 8b 75 08 75 2b 8b 90 d0 12 00 00 83 fa 02 75 20 48 8b 88 d8 12 RSP: 0018:ffff88018f62f020 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffff8801899a0500 RBX: dffffc0000000000 RCX: ffffc90001e6a000 RDX: 0000000000000000 RSI: ffffffff819c5761 RDI: 0000000000000005 RBP: ffff88018f62f020 R08: ffff8801899a0500 R09: ffffed0031ec5daf R10: ffffed0031ec5daf R11: 0000000000000003 R12: ffffea000707fe00 R13: 000000000000000e R14: 0000000000000000 R15: dffffc0000000000 pagecache_get_page+0x15f/0xf00 mm/filemap.c:1562 grab_cache_page_write_begin+0x75/0xa0 mm/filemap.c:3104 simple_write_begin+0x9d/0x3a0 fs/libfs.c:436 generic_perform_write+0x3aa/0x6a0 mm/filemap.c:3154 __generic_file_write_iter+0x26e/0x630 mm/filemap.c:3279 generic_file_write_iter+0x436/0x870 mm/filemap.c:3307 call_write_iter include/linux/fs.h:1825 [inline] do_iter_readv_writev+0x8b0/0xa80 fs/read_write.c:680 do_iter_write+0x185/0x5f0 fs/read_write.c:959 vfs_iter_write+0x77/0xb0 fs/read_write.c:972 iter_file_splice_write+0x90d/0x1050 fs/splice.c:750 do_splice_from fs/splice.c:852 [inline] direct_splice_actor+0x128/0x190 fs/splice.c:1019 splice_direct_to_actor+0x318/0x8f0 fs/splice.c:974 do_splice_direct+0x2d4/0x420 fs/splice.c:1062 do_sendfile+0x62a/0xe20 fs/read_write.c:1440 __do_sys_sendfile64 fs/read_write.c:1495 [inline] __se_sys_sendfile64 fs/read_write.c:1487 [inline] __x64_sys_sendfile64+0x15d/0x250 fs/read_write.c:1487 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:00007fcfee7efc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000457579 RDX: 00000000200001c0 RSI: 0000000000000003 RDI: 0000000000000003 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000a198 R11: 0000000000000246 R12: 00007fcfee7f06d4 R13: 00000000004c34e4 R14: 00000000004d5298 R15: 00000000ffffffff Allocated by task 7004: 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 8538: 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 ffff8801bee86440 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 0 bytes inside of 2048-byte region [ffff8801bee86440, ffff8801bee86c40) The buggy address belongs to the page: page:ffffea0006fba180 count:1 mapcount:0 mapping:ffff8801da800c40 index:0xffff8801bee87540 compound_mapcount: 0 flags: 0x2fffc0000010200(slab|head) raw: 02fffc0000010200 ffffea0006fc0888 ffffea000762e988 ffff8801da800c40 raw: ffff8801bee87540 ffff8801bee86440 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801bee86300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801bee86380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801bee86400: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8801bee86480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801bee86500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================