IPv6: ADDRCONF(NETDEV_UP): vxcan1: link is not ready
8021q: adding VLAN 0 to HW filter on device batadv0
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BUG: KASAN: use-after-free in batadv_interface_tx+0x160a/0x18b0 net/batman-adv/soft-interface.c:226
Read of size 2 at addr ffff8880907420cb by task syz-executor172/7715

CPU: 0 PID: 7715 Comm: syz-executor172 Not tainted 4.20.0+ #297
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+0x1d3/0x2c6 lib/dump_stack.c:113
 print_address_description.cold.5+0x9/0x1ff mm/kasan/report.c:187
 kasan_report.cold.6+0x1b/0x39 mm/kasan/report.c:317
 __asan_report_load_n_noabort+0xf/0x20 mm/kasan/generic_report.c:145
 batadv_interface_tx+0x160a/0x18b0 net/batman-adv/soft-interface.c:226
 __netdev_start_xmit include/linux/netdevice.h:4382 [inline]
 netdev_start_xmit include/linux/netdevice.h:4391 [inline]
 dev_direct_xmit+0x36c/0x6a0 net/core/dev.c:3930
 packet_direct_xmit+0xfb/0x170 net/packet/af_packet.c:246
 packet_snd net/packet/af_packet.c:2932 [inline]
 packet_sendmsg+0x298a/0x6ad0 net/packet/af_packet.c:2957
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:631
 __sys_sendto+0x3d7/0x670 net/socket.c:1788
 __do_sys_sendto net/socket.c:1800 [inline]
 __se_sys_sendto net/socket.c:1796 [inline]
 __ia32_sys_sendto+0xdf/0x1a0 net/socket.c:1796
 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
 do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f0e849
Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000ffb146ec EFLAGS: 00000282 ORIG_RAX: 0000000000000171
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000180
RDX: 000000000000000e RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 7798:
 save_stack+0x43/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 kasan_kmalloc+0xcb/0xd0 mm/kasan/common.c:482
 __do_kmalloc_node mm/slab.c:3671 [inline]
 __kmalloc_node_track_caller+0x4d/0x70 mm/slab.c:3685
 __kmalloc_reserve.isra.40+0x41/0xe0 net/core/skbuff.c:140
 __alloc_skb+0x155/0x760 net/core/skbuff.c:208
 alloc_skb include/linux/skbuff.h:1011 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline]
 netlink_sendmsg+0xb29/0xfc0 net/netlink/af_netlink.c:1892
 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 7798:
 save_stack+0x43/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:444
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:452
 __cache_free mm/slab.c:3485 [inline]
 kfree+0xcf/0x230 mm/slab.c:3804
 skb_free_head+0x93/0xb0 net/core/skbuff.c:553
 skb_release_data+0x706/0x990 net/core/skbuff.c:573
 skb_release_all+0x4a/0x60 net/core/skbuff.c:627
 __kfree_skb net/core/skbuff.c:641 [inline]
 consume_skb+0x1ae/0x570 net/core/skbuff.c:701
 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
 netlink_unicast+0x5a7/0x750 net/netlink/af_netlink.c:1336
 netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1917
 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

The buggy address belongs to the object at ffff888090742000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 203 bytes inside of
 512-byte region [ffff888090742000, ffff888090742200)
The buggy address belongs to the page:
page:ffffea000241d080 count:1 mapcount:0 mapping:ffff88812c3f0940 index:0x0
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea0002463ec8 ffffea00029897c8 ffff88812c3f0940
raw: 0000000000000000 ffff888090742000 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888090741f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888090742000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888090742080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff888090742100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888090742180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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