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+0xdc4/0xe20 net/batman-adv/bat_iv_ogm.c:951 Write of size 2 at addr ffff8880a127bc16 by task kworker/u4:0/14005 CPU: 0 PID: 14005 Comm: kworker/u4:0 Not tainted 4.14.168-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 7467: 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 __do_kmalloc mm/slab.c:3720 [inline] __kmalloc+0x15d/0x7a0 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+0x12b/0x480 net/batman-adv/tvlv.c:329 batadv_iv_ogm_schedule+0xba0/0xe20 net/batman-adv/bat_iv_ogm.c:945 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 Freed by task 2319: 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:8724 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 ffff8880a127bc00 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 22 bytes inside of 192-byte region [ffff8880a127bc00, ffff8880a127bcc0) The buggy address belongs to the page: page:ffffea0002849ec0 count:1 mapcount:0 mapping:ffff8880a127b000 index:0x0 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffff8880a127b000 0000000000000000 0000000100000010 raw: ffffea00023ed060 ffffea00025943a0 ffff8880aa800040 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a127bb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a127bb80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8880a127bc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a127bc80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8880a127bd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================