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BUG: KASAN: slab-out-of-bounds in sctp_send_reset_streams+0xadf/0xc10 net/sctp/stream.c:314
Read of size 2 at addr ffff8801d84aa0c8 by task syz-executor2/7472

CPU: 0 PID: 7472 Comm: syz-executor2 Not tainted 4.15.0-rc3+ #222
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+0xadf/0xc10 net/sctp/stream.c:314
 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:00007fccb1cc5c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452a39
RDX: 0000000000000077 RSI: 0000000000000084 RDI: 0000000000000015
RBP: 000000000000041b R08: 0000000000000008 R09: 0000000000000000
R10: 0000000020e73ff8 R11: 0000000000000212 R12: 00000000006f4328
R13: 00000000ffffffff R14: 00007fccb1cc66d4 R15: 0000000000000000

Allocated by task 7472:
 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:3708 [inline]
 __kmalloc_track_caller+0x15e/0x760 mm/slab.c:3723
 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 6029:
 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+0xca/0x250 mm/slab.c:3803
 kvm_destroy_vm_debugfs arch/x86/kvm/../../../virt/kvm/kvm_main.c:565 [inline]
 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:715 [inline]
 kvm_put_kvm+0x28e/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
 get_signal+0x73f/0x16c0 kernel/signal.c:2335
 do_signal+0x94/0x1ee0 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158
 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+0x94/0x96

The buggy address belongs to the object at ffff8801d84aa0c0
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 8 bytes inside of
 32-byte region [ffff8801d84aa0c0, ffff8801d84aa0e0)
The buggy address belongs to the page:
page:0000000054d4bfec count:1 mapcount:0 mapping:0000000023f19f63 index:0xffff8801d84aafc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801d84aa000 ffff8801d84aafc1 0000000100000032
raw: ffffea0007651da0 ffffea00071e6f60 ffff8801db0001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d84a9f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801d84aa000: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8801d84aa080: fb fb fb fb fc fc fc fc 00 fc fc fc fc fc fc fc
                                              ^
 ffff8801d84aa100: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d84aa180: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
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