netlink: 4 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor3'. ================================================================== BUG: KASAN: use-after-free in __dev_queue_xmit+0x33ab/0x3950 net/core/dev.c:3772 Read of size 8 at addr ffff8801c15a1240 by task kworker/u4:5/7397 CPU: 0 PID: 7397 Comm: kworker/u4:5 Not tainted 4.19.0-rc5+ #237 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c4/0x2b4 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+0x33ab/0x3950 net/core/dev.c:3772 dev_queue_xmit+0x17/0x20 net/core/dev.c:3838 neigh_resolve_output+0x681/0xaf0 net/core/neighbour.c:1364 neigh_output include/net/neighbour.h:483 [inline] ip6_finish_output2+0xc91/0x27a0 net/ipv6/ip6_output.c:120 ip6_finish_output+0x5fe/0xbc0 net/ipv6/ip6_output.c:154 NF_HOOK_COND include/linux/netfilter.h:276 [inline] ip6_output+0x23e/0xa00 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:444 [inline] ip6_local_out+0xc5/0x1b0 net/ipv6/output_core.c:176 ip6_send_skb+0xbc/0x340 net/ipv6/ip6_output.c:1695 ip6_push_pending_frames+0xc5/0xf0 net/ipv6/ip6_output.c:1715 icmpv6_push_pending_frames+0x34a/0x540 net/ipv6/icmp.c:288 icmp6_send+0x265c/0x2d70 net/ipv6/icmp.c:580 icmpv6_send+0x180/0x310 net/ipv6/ip6_icmp.c:43 ip6_link_failure+0xb8/0x950 net/ipv6/route.c:2236 dst_link_failure include/net/dst.h:427 [inline] ndisc_error_report+0xd1/0x1c0 net/ipv6/ndisc.c:695 neigh_invalidate+0x246/0x550 net/core/neighbour.c:894 neigh_timer_handler+0xb07/0xdf0 net/core/neighbour.c:980 call_timer_fn+0x272/0x920 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers+0x7e5/0xc70 kernel/time/timer.c:1682 run_timer_softirq+0x52/0xb0 kernel/time/timer.c:1695 __do_softirq+0x30b/0xad8 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x17f/0x1c0 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1cb/0x760 arch/x86/kernel/apic/apic.c:1056 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:864 RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:798 [inline] RIP: 0010:__local_bh_enable_ip+0x193/0x260 kernel/softirq.c:194 Code: 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 c8 00 00 00 48 83 3d 9e 66 e7 07 00 74 5b fb 66 0f 1f 44 00 00 <65> 8b 05 46 62 b7 7e 85 c0 75 05 e8 14 f2 b5 ff 5b 41 5c 41 5d 5d RSP: 0018:ffff880196b9f320 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: 0000000000000200 RCX: 1ffff10037a4612e RDX: 1ffffffff1263e43 RSI: 0000000000000000 RDI: ffffffff8931f218 RBP: ffff880196b9f338 R08: ffff8801bd230970 R09: 0000000000000007 R10: 0000000000000000 R11: ffff8801bd230080 R12: ffffffff863dfa31 R13: ffff8801bd230080 R14: 0000000000000001 R15: dffffc0000000000 local_bh_enable include/linux/bottom_half.h:32 [inline] get_next_corpse net/netfilter/nf_conntrack_core.c:1866 [inline] nf_ct_iterate_cleanup+0x298/0x5c0 net/netfilter/nf_conntrack_core.c:1889 nf_conntrack_cleanup_net_list+0xd7/0x330 net/netfilter/nf_conntrack_core.c:2076 nf_conntrack_pernet_exit+0x11d/0x170 net/netfilter/nf_conntrack_standalone.c:663 ops_exit_list.isra.7+0x105/0x160 net/core/net_namespace.c:156 cleanup_net+0x555/0xb10 net/core/net_namespace.c:551 process_one_work+0xc90/0x1b90 kernel/workqueue.c:2153 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 Allocated by task 5836: 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:555 [inline] kzalloc_node include/linux/slab.h:718 [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:2114 [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:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2116 __sys_sendmsg+0x11d/0x280 net/socket.c:2154 __do_sys_sendmsg net/socket.c:2163 [inline] __se_sys_sendmsg net/socket.c:2161 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2161 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 23329: 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:236 [inline] rcu_do_batch kernel/rcu/tree.c:2576 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2880 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2847 [inline] rcu_process_callbacks+0xf23/0x2670 kernel/rcu/tree.c:2864 __do_softirq+0x30b/0xad8 kernel/softirq.c:292 The buggy address belongs to the object at ffff8801c15a1240 which belongs to the cache kmalloc-1024 of size 1024 The buggy address is located 0 bytes inside of 1024-byte region [ffff8801c15a1240, ffff8801c15a1640) The buggy address belongs to the page: page:ffffea0007056800 count:1 mapcount:0 mapping:ffff8801da800ac0 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000008100(slab|head) raw: 02fffc0000008100 ffffea0007600d88 ffffea0006fe3e88 ffff8801da800ac0 raw: 0000000000000000 ffff8801c15a0040 0000000100000007 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c15a1100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c15a1180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8801c15a1200: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8801c15a1280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c15a1300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================