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BUG: KASAN: use-after-free in perf_output_read_group kernel/events/core.c:5882 [inline]
BUG: KASAN: use-after-free in perf_output_read+0xe58/0xfc0 kernel/events/core.c:5917
Read of size 8 at addr ffff8881d20d9508 by task syz-executor.3/15428

CPU: 0 PID: 15428 Comm: syz-executor.3 Not tainted 4.14.127+ #9
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x10e lib/dump_stack.c:53
 print_address_description+0x60/0x226 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+0xae/0x2d5 mm/kasan/report.c:393

Allocated by task 15416:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc.part.0+0x4f/0xd0 mm/kasan/kasan.c:551
 __kmalloc+0x143/0x340 mm/slub.c:3760
 kmalloc include/linux/slab.h:493 [inline]
 load_elf_phdrs+0x118/0x1b0 fs/binfmt_elf.c:431
 load_elf_binary+0x7dc/0x4530 fs/binfmt_elf.c:824
 search_binary_handler fs/exec.c:1638 [inline]
 search_binary_handler+0x13f/0x6d0 fs/exec.c:1616
 exec_binprm fs/exec.c:1680 [inline]
 do_execveat_common.isra.0+0xf5f/0x1c30 fs/exec.c:1802
 do_execve fs/exec.c:1847 [inline]
 SYSC_execve fs/exec.c:1928 [inline]
 SyS_execve+0x34/0x40 fs/exec.c:1923
 do_syscall_64+0x19b/0x510 arch/x86/entry/common.c:292

Freed by task 15416:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xb0/0x190 mm/kasan/kasan.c:524
 slab_free_hook mm/slub.c:1389 [inline]
 slab_free_freelist_hook mm/slub.c:1410 [inline]
 slab_free mm/slub.c:2966 [inline]
 kfree+0xf5/0x310 mm/slub.c:3897
 load_elf_binary+0x1bf2/0x4530 fs/binfmt_elf.c:1096
 search_binary_handler fs/exec.c:1638 [inline]
 search_binary_handler+0x13f/0x6d0 fs/exec.c:1616
 exec_binprm fs/exec.c:1680 [inline]
 do_execveat_common.isra.0+0xf5f/0x1c30 fs/exec.c:1802
 do_execve fs/exec.c:1847 [inline]
 SYSC_execve fs/exec.c:1928 [inline]
 SyS_execve+0x34/0x40 fs/exec.c:1923
 do_syscall_64+0x19b/0x510 arch/x86/entry/common.c:292

The buggy address belongs to the object at ffff8881d20d9400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 264 bytes inside of
 512-byte region [ffff8881d20d9400, ffff8881d20d9600)
The buggy address belongs to the page:
page:ffffea0007483600 count:1 mapcount:0 mapping:          (null) index:0x0 compound_mapcount: 0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 0000000000000000 0000000000000000 00000001000c000c
raw: ffffea0007069780 0000000300000003 ffff8881d6402c00 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881d20d9400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881d20d9480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881d20d9500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff8881d20d9580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881d20d9600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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