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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 ffff8801d88f7c08 by task syz-executor6/15841

CPU: 1 PID: 15841 Comm: syz-executor6 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: 0033:0x452a39
RSP: 002b:00007f9793fadc58 EFLAGS: 00000212 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00000000007580d8 RCX: 0000000000452a39
RDX: 0000000000000077 RSI: 0000000000000084 RDI: 0000000000000016
RBP: 0000000000000125 R08: 0000000000000008 R09: 0000000000000000
R10: 0000000020e73ff8 R11: 0000000000000212 R12: 00000000006efc18
R13: 00000000ffffffff R14: 00007f9793fae6d4 R15: 0000000000000007

Allocated by task 15841:
 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 1599:
 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
 simple_xattrs_free include/linux/xattr.h:97 [inline]
 shmem_evict_inode+0x1b0/0xb30 mm/shmem.c:1083
 evict+0x481/0x920 fs/inode.c:552
 iput_final fs/inode.c:1514 [inline]
 iput+0x7b9/0xaf0 fs/inode.c:1541
 dentry_unlink_inode+0x4b0/0x5e0 fs/dcache.c:376
 __dentry_kill+0x3b7/0x6d0 fs/dcache.c:573
 dentry_kill fs/dcache.c:614 [inline]
 dput.part.23+0x5a0/0x830 fs/dcache.c:824
 dput+0x1f/0x30 fs/dcache.c:788
 SYSC_renameat2 fs/namei.c:4615 [inline]
 SyS_renameat2 fs/namei.c:4500 [inline]
 SYSC_rename fs/namei.c:4651 [inline]
 SyS_rename+0x909/0xc90 fs/namei.c:4649
 entry_SYSCALL_64_fastpath+0x1f/0x96

The buggy address belongs to the object at ffff8801d88f7c00
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 8 bytes inside of
 32-byte region [ffff8801d88f7c00, ffff8801d88f7c20)
The buggy address belongs to the page:
page:00000000fb6750ed count:1 mapcount:0 mapping:0000000045320cf5 index:0xffff8801d88f7fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801d88f7000 ffff8801d88f7fc1 0000000100000036
raw: ffffea000716a960 ffffea00071067e0 ffff8801dac001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d88f7b00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d88f7b80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8801d88f7c00: 00 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc
                      ^
 ffff8801d88f7c80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801d88f7d00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
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