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BUG: KASAN: slab-out-of-bounds in _copy_to_user+0x9a/0xc0 lib/usercopy.c:27
Read of size 337 at addr ffff8801ab957ffd by task syz-executor2/29185

CPU: 0 PID: 29185 Comm: syz-executor2 Not tainted 4.14.74+ #17
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x11b lib/dump_stack.c:53
 print_address_description+0x60/0x22b mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report.cold.6+0x11b/0x2dd mm/kasan/report.c:409
 _copy_to_user+0x9a/0xc0 lib/usercopy.c:27
 copy_to_user include/linux/uaccess.h:155 [inline]
 bpf_test_finish.isra.0+0xc8/0x190 net/bpf/test_run.c:59
 bpf_prog_test_run_skb+0x4d0/0x8c0 net/bpf/test_run.c:144
 bpf_prog_test_run kernel/bpf/syscall.c:1330 [inline]
 SYSC_bpf kernel/bpf/syscall.c:1602 [inline]
 SyS_bpf+0x79d/0x3640 kernel/bpf/syscall.c:1547
 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x457579
RSP: 002b:00007f2ee1c2ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579
RDX: 0000000000000028 RSI: 0000000020000100 RDI: 000000000000000a
RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2ee1c2f6d4
R13: 00000000004bd8a6 R14: 00000000004cc208 R15: 00000000ffffffff

Allocated by task 28661:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc.part.1+0x4f/0xd0 mm/kasan/kasan.c:551
 slab_post_alloc_hook mm/slab.h:442 [inline]
 slab_alloc_node mm/slub.c:2723 [inline]
 slab_alloc mm/slub.c:2731 [inline]
 kmem_cache_alloc+0xe4/0x2b0 mm/slub.c:2736
 kmem_cache_zalloc include/linux/slab.h:651 [inline]
 create_pid_namespace kernel/pid_namespace.c:116 [inline]
 copy_pid_ns+0x1ae/0xa90 kernel/pid_namespace.c:186
 create_new_namespaces+0x28a/0x750 kernel/nsproxy.c:94
 copy_namespaces+0x289/0x320 kernel/nsproxy.c:165
 copy_process.part.6+0x1fb6/0x6530 kernel/fork.c:1765
 copy_process kernel/fork.c:1573 [inline]
 _do_fork+0x1c2/0xd50 kernel/fork.c:2054
 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 70:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xac/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]
 kmem_cache_free+0x12d/0x350 mm/slub.c:2988
 __rcu_reclaim kernel/rcu/rcu.h:195 [inline]
 rcu_do_batch kernel/rcu/tree.c:2691 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2945 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2912 [inline]
 rcu_process_callbacks+0x54d/0xee0 kernel/rcu/tree.c:2929
 __do_softirq+0x215/0x997 kernel/softirq.c:288

The buggy address belongs to the object at ffff8801ab956fc0
 which belongs to the cache pid_namespace of size 2256
The buggy address is located 1901 bytes to the right of
 2256-byte region [ffff8801ab956fc0, ffff8801ab957890)
The buggy address belongs to the page:
page:ffffea0006ae5400 count:1 mapcount:0 mapping:          (null) index:0x0 compound_mapcount: 0
flags: 0x4000000000008100(slab|head)
raw: 4000000000008100 0000000000000000 0000000000000000 00000001800d000d
raw: ffffea00069f8200 0000000400000004 ffff8801d9cc4e00 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801ab957e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801ab957f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8801ab957f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                                ^
 ffff8801ab958000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801ab958080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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