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BUG: KASAN: slab-out-of-bounds in sctp_setsockopt_delayed_ack net/sctp/socket.c:2771 [inline]
BUG: KASAN: slab-out-of-bounds in sctp_setsockopt net/sctp/socket.c:4499 [inline]
BUG: KASAN: slab-out-of-bounds in sctp_setsockopt+0x9488/0x95e0 net/sctp/socket.c:4431
Write of size 4 at addr ffff888099717f08 by task syz-executor.1/28398
CPU: 1 PID: 28398 Comm: syz-executor.1 Not tainted 5.8.0-rc6-next-20200724-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x18f/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 sctp_setsockopt_delayed_ack net/sctp/socket.c:2771 [inline]
 sctp_setsockopt net/sctp/socket.c:4499 [inline]
 sctp_setsockopt+0x9488/0x95e0 net/sctp/socket.c:4431
 __sys_setsockopt+0x337/0x6a0 net/socket.c:2137
 __do_sys_setsockopt net/socket.c:2153 [inline]
 __se_sys_setsockopt net/socket.c:2150 [inline]
 __x64_sys_setsockopt+0xba/0x150 net/socket.c:2150
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c369
Code: Bad RIP value.
RSP: 002b:00007f3fa1ce0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 000000000002e9c0 RCX: 000000000045c369
RDX: 0000000000000010 RSI: 0000000000000084 RDI: 0000000000000003
RBP: 000000000078bf50 R08: 0000000000000008 R09: 0000000000000000
R10: 0000000020000080 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007fff2d994f8f R14: 00007f3fa1ce19c0 R15: 000000000078bf0c
Allocated by task 28398:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
 __do_kmalloc mm/slab.c:3655 [inline]
 __kmalloc_track_caller+0x1a6/0x310 mm/slab.c:3670
 memdup_user+0x22/0xd0 mm/util.c:172
 sctp_setsockopt net/sctp/socket.c:4452 [inline]
 sctp_setsockopt+0x17a/0x95e0 net/sctp/socket.c:4431
 __sys_setsockopt+0x337/0x6a0 net/socket.c:2137
 __do_sys_setsockopt net/socket.c:2153 [inline]
 __se_sys_setsockopt net/socket.c:2150 [inline]
 __x64_sys_setsockopt+0xba/0x150 net/socket.c:2150
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
The buggy address belongs to the object at ffff888099717f00
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 8 bytes inside of
 32-byte region [ffff888099717f00, ffff888099717f20)
The buggy address belongs to the page:
page:000000000399fab8 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888099717fc1 pfn:0x99717
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00026599c8 ffffea000260e808 ffff8880aa000100
raw: ffff888099717fc1 ffff888099717000 000000010000003f 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
 ffff888099717e00: fa fb fb fb fc fc fc fc 05 fc fc fc fc fc fc fc
 ffff888099717e80: 00 00 fc fc fc fc fc fc 00 00 fc fc fc fc fc fc
>ffff888099717f00: 00 fc fc fc fc fc fc fc 00 00 00 05 fc fc fc fc
                      ^
 ffff888099717f80: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888099718000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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