IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready batman_adv: batadv0: Interface deactivated: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_0 ================================================================== BUG: KASAN: use-after-free in batadv_iv_ogm_schedule+0xd9b/0xdf0 net/batman-adv/bat_iv_ogm.c:951 Write of size 2 at addr ffff8880937e0c96 by task kworker/u4:0/5 CPU: 0 PID: 5 Comm: kworker/u4:0 Not tainted 4.14.172-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+0x13e/0x194 lib/dump_stack.c:58 print_address_description.cold+0x7c/0x1e2 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+0xa9/0x2ae mm/kasan/report.c:393 batadv_iv_ogm_schedule+0xd9b/0xdf0 net/batman-adv/bat_iv_ogm.c:951 batadv_iv_send_outstanding_bat_ogm_packet+0x4ad/0x6a0 net/batman-adv/bat_iv_ogm.c:1809 process_one_work+0x813/0x1540 kernel/workqueue.c:2114 worker_thread+0x5d1/0x1070 kernel/workqueue.c:2248 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Allocated by task 8804: save_stack+0x32/0xa0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc mm/kasan/kasan.c:551 [inline] kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:529 __do_kmalloc mm/slab.c:3720 [inline] __kmalloc+0x15b/0x7c0 mm/slab.c:3729 kmalloc include/linux/slab.h:493 [inline] batadv_tvlv_realloc_packet_buff net/batman-adv/tvlv.c:288 [inline] batadv_tvlv_container_ogm_append+0x12a/0x490 net/batman-adv/tvlv.c:329 batadv_iv_ogm_schedule+0xb78/0xdf0 net/batman-adv/bat_iv_ogm.c:945 batadv_iv_send_outstanding_bat_ogm_packet+0x4ad/0x6a0 net/batman-adv/bat_iv_ogm.c:1809 process_one_work+0x813/0x1540 kernel/workqueue.c:2114 worker_thread+0x5d1/0x1070 kernel/workqueue.c:2248 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Freed by task 2330: save_stack+0x32/0xa0 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+0xcb/0x260 mm/slab.c:3815 batadv_iv_ogm_iface_disable+0x34/0x70 net/batman-adv/bat_iv_ogm.c:393 batadv_hardif_disable_interface.cold+0x61e/0x867 net/batman-adv/hard-interface.c:836 batadv_softif_destroy_netlink+0xa3/0x140 net/batman-adv/soft-interface.c:1134 default_device_exit_batch+0x209/0x380 net/core/dev.c:8734 ops_exit_list.isra.0+0xef/0x140 net/core/net_namespace.c:145 cleanup_net+0x3bb/0x820 net/core/net_namespace.c:484 process_one_work+0x813/0x1540 kernel/workqueue.c:2114 worker_thread+0x5d1/0x1070 kernel/workqueue.c:2248 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 The buggy address belongs to the object at ffff8880937e0c80 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 22 bytes inside of 64-byte region [ffff8880937e0c80, ffff8880937e0cc0) The buggy address belongs to the page: page:ffffea00024df800 count:1 mapcount:0 mapping:ffff8880937e0000 index:0x0 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffff8880937e0000 0000000000000000 0000000100000020 raw: ffffea00022b09e0 ffffea0002934e20 ffff88812fe56340 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880937e0b80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8880937e0c00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8880937e0c80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff8880937e0d00: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ffff8880937e0d80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================