audit: type=1400 audit(1512798218.287:7): avc:  denied  { map } for  pid=3151 comm="syzkaller459536" path="/root/syzkaller459536944" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
==================================================================
BUG: KASAN: slab-out-of-bounds in sctp_send_reset_streams+0xadf/0xc10 net/sctp/stream.c:314
Read of size 2 at addr ffff8801c48af5c8 by task syzkaller459536/3151

CPU: 0 PID: 3151 Comm: syzkaller459536 Not tainted 4.15.0-rc2-next-20171208+ #63
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: 0033:0x43ff59
RSP: 002b:00007ffc31cf0148 EFLAGS: 00000217 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043ff59
RDX: 0000000000000077 RSI: 0000000000000084 RDI: 0000000000000005
RBP: 00000000006ca018 R08: 0000000000000008 R09: 000000000000001c
R10: 000000002018b000 R11: 0000000000000217 R12: 00000000004018c0
R13: 0000000000401950 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 3151:
 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:3712 [inline]
 __kmalloc_track_caller+0x15e/0x760 mm/slab.c:3727
 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 1635:
 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:3492 [inline]
 kfree+0xca/0x250 mm/slab.c:3807
 selinux_cred_free+0x48/0x70 security/selinux/hooks.c:3815
 security_cred_free+0x48/0x80 security/security.c:995
 put_cred_rcu+0x106/0x400 kernel/cred.c:117
 __rcu_reclaim kernel/rcu/rcu.h:172 [inline]
 rcu_do_batch kernel/rcu/tree.c:2675 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2934 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2901 [inline]
 rcu_process_callbacks+0xd74/0x17d0 kernel/rcu/tree.c:2918
 __do_softirq+0x29d/0xbb2 kernel/softirq.c:285

The buggy address belongs to the object at ffff8801c48af5c0
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 8 bytes inside of
 32-byte region [ffff8801c48af5c0, ffff8801c48af5e0)
The buggy address belongs to the page:
page:0000000033b4455d count:1 mapcount:0 mapping:000000009cbb8b0b index:0xffff8801c48affc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801c48af000 ffff8801c48affc1 000000010000003f
raw: ffffea0007142fa0 ffffea000713a3a0 ffff8801dac001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c48af480: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801c48af500: 00 01 fc fc fc fc fc fc 00 00 01 fc fc fc fc fc
>ffff8801c48af580: fb fb fb fb fc fc fc fc 00 fc fc fc fc fc fc fc
                                              ^
 ffff8801c48af600: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801c48af680: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
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