batman_adv: batadv0: Interface deactivated: batadv_slave_0
batman_adv: batadv0: Removing interface: batadv_slave_0
batman_adv: batadv0: Interface deactivated: batadv_slave_1
batman_adv: batadv0: Removing interface: batadv_slave_1
==================================================================
BUG: KASAN: use-after-free in batadv_iv_ogm_schedule+0xdc4/0xe20 net/batman-adv/bat_iv_ogm.c:951
Write of size 2 at addr ffff88808cb257d6 by task kworker/u4:2/29

CPU: 0 PID: 29 Comm: kworker/u4:2 Not tainted 4.14.170-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x142/0x197 lib/dump_stack.c:58
 print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xa9/0x2af mm/kasan/report.c:393
 __asan_report_store2_noabort+0x17/0x20 mm/kasan/report.c:433
 batadv_iv_ogm_schedule+0xdc4/0xe20 net/batman-adv/bat_iv_ogm.c:951
 batadv_iv_send_outstanding_bat_ogm_packet+0x4a1/0x680 net/batman-adv/bat_iv_ogm.c:1809
 process_one_work+0x863/0x1600 kernel/workqueue.c:2114
 worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248
 kthread+0x319/0x430 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

Allocated by task 17926:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x45/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc mm/kasan/kasan.c:551 [inline]
 kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529
 kmem_cache_alloc_trace+0x152/0x790 mm/slab.c:3618
 kmalloc include/linux/slab.h:488 [inline]
 batadv_iv_ogm_iface_enable+0xff/0x2e0 net/batman-adv/bat_iv_ogm.c:374
 batadv_hardif_enable_interface+0x251/0xa10 net/batman-adv/hard-interface.c:746
 batadv_softif_slave_add+0x8b/0xf0 net/batman-adv/soft-interface.c:889
 do_set_master net/core/rtnetlink.c:1961 [inline]
 do_set_master+0x19f/0x200 net/core/rtnetlink.c:1936
 do_setlink+0x99f/0x2c20 net/core/rtnetlink.c:2098
 rtnl_newlink+0x11a7/0x1700 net/core/rtnetlink.c:2660
 rtnetlink_rcv_msg+0x3da/0xb70 net/core/rtnetlink.c:4315
 netlink_rcv_skb+0x14f/0x3c0 net/netlink/af_netlink.c:2432
 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:4327
 netlink_unicast_kernel net/netlink/af_netlink.c:1286 [inline]
 netlink_unicast+0x44d/0x650 net/netlink/af_netlink.c:1312
 netlink_sendmsg+0x7c4/0xc60 net/netlink/af_netlink.c:1877
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xce/0x110 net/socket.c:656
 SYSC_sendto+0x206/0x310 net/socket.c:1763
 SyS_sendto+0x40/0x50 net/socket.c:1731
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 7425:
 save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
 save_stack+0x45/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xcc/0x270 mm/slab.c:3815
 batadv_iv_ogm_iface_disable+0x39/0x80 net/batman-adv/bat_iv_ogm.c:393
 batadv_hardif_disable_interface.cold+0x605/0x840 net/batman-adv/hard-interface.c:836
 batadv_softif_destroy_netlink+0xad/0x140 net/batman-adv/soft-interface.c:1134
 default_device_exit_batch+0x22c/0x3d0 net/core/dev.c:8734
 ops_exit_list.isra.0+0xfc/0x150 net/core/net_namespace.c:145
 cleanup_net+0x3ba/0x870 net/core/net_namespace.c:484
 process_one_work+0x863/0x1600 kernel/workqueue.c:2114
 worker_thread+0x5d9/0x1050 kernel/workqueue.c:2248
 kthread+0x319/0x430 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

The buggy address belongs to the object at ffff88808cb257c0
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 22 bytes inside of
 32-byte region [ffff88808cb257c0, ffff88808cb257e0)
The buggy address belongs to the page:
page:ffffea000232c940 count:1 mapcount:0 mapping:ffff88808cb25000 index:0xffff88808cb25fc1
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff88808cb25000 ffff88808cb25fc1 0000000100000034
raw: ffffea00028124e0 ffffea0002a69d60 ffff8880aa8001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808cb25680: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff88808cb25700: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff88808cb25780: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
                                                 ^
 ffff88808cb25800: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff88808cb25880: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================