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BUG: KASAN: slab-out-of-bounds in sctp_send_reset_streams+0xb03/0xc10 net/sctp/stream.c:323
Read of size 2 at addr ffff8801c31e2748 by task syz-executor2/18490

CPU: 0 PID: 18490 Comm: syz-executor2 Not tainted 4.15.0-rc3+ #221
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_load2_noabort+0x14/0x20 mm/kasan/report.c:428
 sctp_send_reset_streams+0xb03/0xc10 net/sctp/stream.c:323
 sctp_setsockopt_reset_streams net/sctp/socket.c:3905 [inline]
 sctp_setsockopt+0x70d/0x5d50 net/sctp/socket.c:4195
 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2968
 SYSC_setsockopt net/socket.c:1829 [inline]
 SyS_setsockopt+0x189/0x360 net/socket.c:1808
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452a39
RSP: 002b:00007f490f45bc58 EFLAGS: 00000212 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f490f45c700 RCX: 0000000000452a39
RDX: 0000000000000077 RSI: 0000000000000084 RDI: 0000000000000013
RBP: 0000000000000000 R08: 0000000000000008 R09: 0000000000000000
R10: 0000000020a50ff8 R11: 0000000000000212 R12: 0000000000000000
R13: 0000000000a6f7ff R14: 00007f490f45c9c0 R15: 0000000000000000

Allocated by task 18490:
 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 mm/slab.c:3711 [inline]
 __kmalloc_track_caller+0x15e/0x760 mm/slab.c:3726
 memdup_user+0x2c/0x90 mm/util.c:164
 sctp_setsockopt_reset_streams net/sctp/socket.c:3897 [inline]
 sctp_setsockopt+0x6a6/0x5d50 net/sctp/socket.c:4195
 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2968
 SYSC_setsockopt net/socket.c:1829 [inline]
 SyS_setsockopt+0x189/0x360 net/socket.c:1808
 entry_SYSCALL_64_fastpath+0x1f/0x96

Freed by task 16852:
 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:3491 [inline]
 kfree+0xca/0x250 mm/slab.c:3806
 kvfree+0x36/0x60 mm/util.c:416
 kvm_arch_free_memslot+0x11b/0x230 arch/x86/kvm/x86.c:8311
 kvm_free_memslot+0xb8/0x110 arch/x86/kvm/../../../virt/kvm/kvm_main.c:536
 kvm_free_memslots+0x9d/0xd0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:549
 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:737 [inline]
 kvm_put_kvm+0x916/0xdf0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:755
 kvm_vm_release+0x42/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:766
 __fput+0x333/0x7f0 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/0x1ae0 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+0x1f/0x96

The buggy address belongs to the object at ffff8801c31e2740
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 8 bytes inside of
 32-byte region [ffff8801c31e2740, ffff8801c31e2760)
The buggy address belongs to the page:
page:000000008b169fe6 count:1 mapcount:0 mapping:00000000c7b26f79 index:0xffff8801c31e2fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801c31e2000 ffff8801c31e2fc1 000000010000003a
raw: ffffea0007629e20 ffffea000715af20 ffff8801db0001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c31e2600: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801c31e2680: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8801c31e2700: fb fb fb fb fc fc fc fc 00 fc fc fc fc fc fc fc
                                              ^
 ffff8801c31e2780: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801c31e2800: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
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