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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 ffff88809e7fa288 by task syz-executor.2/14007
CPU: 0 PID: 14007 Comm: syz-executor.2 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:00007f5991640c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 000000000002eac0 RCX: 000000000045c369
RDX: 0000000000000010 RSI: 0000000000000084 RDI: 0000000000000008
RBP: 000000000078bff0 R08: 0000000000000008 R09: 0000000000000000
R10: 0000000020000340 R11: 0000000000000246 R12: 000000000078bfac
R13: 00007fffcec354df R14: 00007f59916419c0 R15: 000000000078bfac
Allocated by task 14007:
 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 ffff88809e7fa280
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 8 bytes inside of
 32-byte region [ffff88809e7fa280, ffff88809e7fa2a0)
The buggy address belongs to the page:
page:0000000073e75cb2 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88809e7fafc1 pfn:0x9e7fa
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00029ac448 ffffea0002699608 ffff8880aa000100
raw: ffff88809e7fafc1 ffff88809e7fa000 0000000100000037 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
 ffff88809e7fa180: 00 fc fc fc fc fc fc fc fa fb fb fb fc fc fc fc
 ffff88809e7fa200: 05 fc fc fc fc fc fc fc 05 fc fc fc fc fc fc fc
>ffff88809e7fa280: 00 fc fc fc fc fc fc fc fa fb fb fb fc fc fc fc
                      ^
 ffff88809e7fa300: fa fb fb fb fc fc fc fc 00 00 00 02 fc fc fc fc
 ffff88809e7fa380: 00 fc fc fc fc fc fc fc fa fb fb fb fc fc fc fc
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