==================================================================
BUG: KASAN: slab-out-of-bounds in __read_once_size include/linux/compiler.h:183 [inline]
BUG: KASAN: slab-out-of-bounds in perf_event_fd_array_release+0x435/0x480 kernel/bpf/arraymap.c:544
Read of size 8 at addr ffff8801bd3f4800 by task syz-executor6/10381

CPU: 0 PID: 10381 Comm: syz-executor6 Not tainted 4.15.0-rc8+ #264
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 print_address_description+0x73/0x250 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x25b/0x340 mm/kasan/report.c:409
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430
 __read_once_size include/linux/compiler.h:183 [inline]
 perf_event_fd_array_release+0x435/0x480 kernel/bpf/arraymap.c:544
 bpf_map_release+0x84/0xc0 kernel/bpf/syscall.c:257
 __fput+0x327/0x7e0 fs/file_table.c:210
 ____fput+0x15/0x20 fs/file_table.c:244
 task_work_run+0x199/0x270 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x9bb/0x1ad0 kernel/exit.c:865
 do_group_exit+0x149/0x400 kernel/exit.c:968
 SYSC_exit_group kernel/exit.c:979 [inline]
 SyS_exit_group+0x1d/0x20 kernel/exit.c:977
 entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x452df9
RSP: 002b:0000000000a2fa08 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000071bec8 RCX: 0000000000452df9
RDX: 0000000000000000 RSI: 0000000000721768 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000026c
R10: 000000000000000c R11: 0000000000000202 R12: 0000000000a2f9b0
R13: 000000000071bea0 R14: 0000000000000327 R15: 000000000000000c

Allocated by task 10401:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
 __do_kmalloc_node mm/slab.c:3672 [inline]
 __kmalloc_node+0x47/0x70 mm/slab.c:3679
 kmalloc_node include/linux/slab.h:541 [inline]
 bpf_map_area_alloc+0x32/0x80 kernel/bpf/syscall.c:123
 array_map_alloc+0x351/0xa00 kernel/bpf/arraymap.c:96
 fd_array_map_alloc+0x57/0x70 kernel/bpf/arraymap.c:341
 find_and_alloc_map kernel/bpf/syscall.c:105 [inline]
 map_create kernel/bpf/syscall.c:404 [inline]
 SYSC_bpf kernel/bpf/syscall.c:1708 [inline]
 SyS_bpf+0x7f8/0x4400 kernel/bpf/syscall.c:1685
 entry_SYSCALL_64_fastpath+0x29/0xa0

Freed by task 28:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3488 [inline]
 kfree+0xd6/0x260 mm/slab.c:3803
 free_proc_entry fs/proc/generic.c:531 [inline]
 pde_put+0x9a/0xf0 fs/proc/generic.c:537
 remove_proc_entry+0x1e3/0x360 fs/proc/generic.c:573
 sctp_proc_exit net/sctp/protocol.c:128 [inline]
 sctp_defaults_exit+0x3f5/0x630 net/sctp/protocol.c:1327
 ops_exit_list.isra.6+0xae/0x150 net/core/net_namespace.c:142
 cleanup_net+0x5c7/0xb50 net/core/net_namespace.c:484
 process_one_work+0xbbf/0x1b10 kernel/workqueue.c:2112
 worker_thread+0x223/0x1990 kernel/workqueue.c:2246
 kthread+0x33c/0x400 kernel/kthread.c:238
 ret_from_fork+0x37/0x50 arch/x86/entry/entry_64.S:530

The buggy address belongs to the object at ffff8801bd3f4700
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 0 bytes to the right of
 256-byte region [ffff8801bd3f4700, ffff8801bd3f4800)
The buggy address belongs to the page:
page:ffffea0006f4fd00 count:1 mapcount:0 mapping:ffff8801bd3f40c0 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801bd3f40c0 0000000000000000 000000010000000c
raw: ffffea0006faaae0 ffffea00071cf0e0 ffff8801dac007c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801bd3f4700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801bd3f4780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801bd3f4800: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
                   ^
 ffff8801bd3f4880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801bd3f4900: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc
==================================================================