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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 ffff8801bc6e5e40 by task syz-executor4/1265

CPU: 1 PID: 1265 Comm: syz-executor4 Not tainted 4.15.0-rc7+ #190
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
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x296/0x310 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264
 entry_SYSCALL_64_fastpath+0x98/0x9a
RIP: 0033:0x452df9
RSP: 002b:00007f3395dd9c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 000000000071bea0 RCX: 0000000000452df9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000013
RBP: 000000000000004e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006ee7f0
R13: 00000000ffffffff R14: 00007f3395dda6d4 R15: 0000000000000000

Allocated by task 1265:
 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:1805 [inline]
 SyS_bpf+0x7f8/0x4400 kernel/bpf/syscall.c:1782
 entry_SYSCALL_64_fastpath+0x23/0x9a

Freed by task 29359:
 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_bprm+0x19d/0x200 fs/exec.c:1414
 do_execveat_common.isra.30+0x1a24/0x23c0 fs/exec.c:1812
 do_execve+0x31/0x40 fs/exec.c:1847
 call_usermodehelper_exec_async+0x457/0x8f0 kernel/umh.c:100
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:524

The buggy address belongs to the object at ffff8801bc6e5d40
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 0 bytes to the right of
 256-byte region [ffff8801bc6e5d40, ffff8801bc6e5e40)
The buggy address belongs to the page:
page:ffffea0006f1b940 count:1 mapcount:0 mapping:ffff8801bc6e50c0 index:0xffff8801bc6e5c00
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801bc6e50c0 ffff8801bc6e5c00 000000010000000a
raw: ffffea00072584e0 ffffea0006f8d3a0 ffff8801dac007c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801bc6e5d00: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff8801bc6e5d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801bc6e5e00: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
                                           ^
 ffff8801bc6e5e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801bc6e5f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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