================================================================== BUG: KASAN: use-after-free in __dev_queue_xmit+0x33f9/0x3950 net/core/dev.c:3772 Read of size 8 at addr ffff8801bc1a3580 by task syz-executor5/17424 CPU: 1 PID: 17424 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_resolve_output+0x67e/0xae0 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+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:arch_local_irq_restore arch/x86/include/asm/paravirt.h:761 [inline] RIP: 0010:queue_work_on+0x122/0x1e0 kernel/workqueue.c:1490 Code: df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 c5 00 00 00 48 83 3d ce c9 e1 07 00 0f 84 95 00 00 00 e8 a3 3d 2d 00 48 89 df 57 9d <0f> 1f 44 00 00 e8 94 3d 2d 00 44 89 e8 48 83 c4 08 5b 41 5c 41 5d RSP: 0018:ffff88016c98f400 EFLAGS: 00000212 ORIG_RAX: ffffffffffffff13 RAX: 0000000000040000 RBX: 0000000000000212 RCX: ffffc9000c300000 RDX: 00000000000002c2 RSI: ffffffff81502aad RDI: 0000000000000212 RBP: ffff88016c98f430 R08: ffff8801be828480 R09: ffffed003b503528 R10: ffffed003b503528 R11: ffff8801da81a943 R12: 0000000000000200 R13: 0000000000000001 R14: 0000000000000000 R15: ffff8801da824080 queue_work include/linux/workqueue.h:512 [inline] call_usermodehelper_exec+0x391/0x520 kernel/umh.c:557 call_modprobe kernel/kmod.c:99 [inline] __request_module+0x548/0xf05 kernel/kmod.c:171 dev_load+0x1f7/0x210 net/core/dev_ioctl.c:354 dev_ioctl+0x1a3/0xcc0 net/core/dev_ioctl.c:486 sock_do_ioctl+0x1f6/0x420 net/socket.c:974 sock_ioctl+0x313/0x690 net/socket.c:1075 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707 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:00007f18adbf5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579 RDX: 0000000020000140 RSI: 0000000000008914 RDI: 0000000000000009 RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f18adbf66d4 R13: 00000000004c2251 R14: 00000000004d3240 R15: 00000000ffffffff Allocated by task 16299: 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_track_caller+0x47/0x70 mm/slab.c:3696 __kmalloc_reserve.isra.39+0x41/0xe0 net/core/skbuff.c:137 __alloc_skb+0x150/0x770 net/core/skbuff.c:205 alloc_skb include/linux/skbuff.h:997 [inline] nlmsg_new include/net/netlink.h:535 [inline] audit_buffer_alloc kernel/audit.c:1680 [inline] audit_log_start+0x57c/0x9d0 kernel/audit.c:1793 audit_seccomp+0x61/0x2a0 kernel/auditsc.c:2493 seccomp_log kernel/seccomp.c:604 [inline] __seccomp_filter+0x369/0xe90 kernel/seccomp.c:767 __secure_computing+0x100/0x370 kernel/seccomp.c:795 syscall_trace_enter+0x4e2/0x1260 arch/x86/entry/common.c:120 do_syscall_64+0x601/0x820 arch/x86/entry/common.c:280 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 26: 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 skb_free_head+0x99/0xc0 net/core/skbuff.c:550 skb_release_data+0x6a4/0x880 net/core/skbuff.c:570 skb_release_all+0x4a/0x60 net/core/skbuff.c:627 __kfree_skb net/core/skbuff.c:641 [inline] kfree_skb+0x1b6/0x580 net/core/skbuff.c:659 kauditd_hold_skb+0x15f/0x190 kernel/audit.c:583 kauditd_send_queue+0x13b/0x180 kernel/audit.c:742 kauditd_thread+0x7d2/0xb60 kernel/audit.c:868 kthread+0x35a/0x440 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff8801bc1a3580 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 0 bytes inside of 2048-byte region [ffff8801bc1a3580, ffff8801bc1a3d80) The buggy address belongs to the page: page:ffffea0006f06880 count:1 mapcount:0 mapping:ffff8801da800c40 index:0xffff8801bc1a3580 compound_mapcount: 0 flags: 0x2fffc0000010200(slab|head) raw: 02fffc0000010200 ffffea0007637008 ffffea000623a288 ffff8801da800c40 raw: ffff8801bc1a3580 ffff8801bc1a2480 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801bc1a3480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801bc1a3500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801bc1a3580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801bc1a3600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801bc1a3680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================