================================================================== 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 ffff888094f41c08 by task syz-executor.4/16566 CPU: 1 PID: 16566 Comm: syz-executor.4 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:00007f9128508c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 000000000002f2c0 RCX: 000000000045c369 RDX: 0000000000000010 RSI: 0000000000000084 RDI: 0000000000000003 RBP: 000000000078bf50 R08: 0000000000000008 R09: 0000000000000000 R10: 0000000020000080 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007ffe31e77fff R14: 00007f91285099c0 R15: 000000000078bf0c Allocated by task 16566: 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 ffff888094f41c00 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 8 bytes inside of 32-byte region [ffff888094f41c00, ffff888094f41c20) The buggy address belongs to the page: page:0000000063af7641 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888094f41fc1 pfn:0x94f41 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002980bc8 ffffea0002772108 ffff8880aa000100 raw: ffff888094f41fc1 ffff888094f41000 0000000100000029 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888094f41b00: fb fb fb fb fc fc fc fc 01 fc fc fc fc fc fc fc ffff888094f41b80: 00 00 fc fc fc fc fc fc 00 fc fc fc fc fc fc fc >ffff888094f41c00: 00 fc fc fc fc fc fc fc 00 00 fc fc fc fc fc fc ^ ffff888094f41c80: 01 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc ffff888094f41d00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ==================================================================