================================================================== BUG: KASAN: stack-out-of-bounds in __list_del_entry_valid+0x10b/0x150 lib/list_debug.c:51 Read of size 8 at addr ffff8801c375fb50 by task syz-executor0/13340 CPU: 1 PID: 13340 Comm: syz-executor0 Not tainted 4.14.0-rc2-next-20170928+ #31 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 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_load8_noabort+0x14/0x20 mm/kasan/report.c:430 __list_del_entry_valid+0x10b/0x150 lib/list_debug.c:51 __list_del_entry include/linux/list.h:116 [inline] list_del include/linux/list.h:124 [inline] __remove_wait_queue include/linux/wait.h:183 [inline] userfaultfd_event_wait_completion+0x535/0x9c0 fs/userfaultfd.c:591 dup_fctx fs/userfaultfd.c:687 [inline] dup_userfaultfd_complete+0x2de/0x480 fs/userfaultfd.c:695 dup_mmap kernel/fork.c:745 [inline] dup_mm kernel/fork.c:1198 [inline] copy_mm+0xe9b/0x1310 kernel/fork.c:1252 copy_process.part.35+0x1f0c/0x4b50 kernel/fork.c:1756 copy_process kernel/fork.c:1569 [inline] _do_fork+0x1ef/0xfe0 kernel/fork.c:2048 SYSC_clone kernel/fork.c:2158 [inline] SyS_clone+0x37/0x50 kernel/fork.c:2152 do_syscall_64+0x26c/0x8d0 arch/x86/entry/common.c:287 entry_SYSCALL64_slow_path+0x25/0x25 RIP: 0033:0x4520a9 RSP: 002b:00007ff8ccfc5c08 EFLAGS: 00000216 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 00000000004520a9 RDX: 0000000020001ffc RSI: 0000000020001f37 RDI: 0000000000000000 RBP: 0000000000000450 R08: 0000000020001000 R09: 0000000000000000 R10: 0000000020001000 R11: 0000000000000216 R12: 00000000004b7454 R13: 00000000ffffffff R14: 0000000000000000 R15: 0000000020001f37 The buggy address belongs to the page: page:ffffea00070dd7c0 count:0 mapcount:0 mapping: (null) index:0x0 flags: 0x200000000000000() raw: 0200000000000000 0000000000000000 0000000000000000 00000000ffffffff raw: dead000000000100 dead000000000200 0000000000000000 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c375fa00: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 ffff8801c375fa80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 >ffff8801c375fb00: f1 f1 04 f2 f2 f2 f2 f2 f2 f2 04 f2 f2 f2 f2 f2 ^ ffff8801c375fb80: f2 f2 00 f2 f2 f2 f2 f2 f2 f2 00 f2 f2 f2 f2 f2 ffff8801c375fc00: f2 f2 00 f2 f2 f2 f2 f2 f2 f2 00 f2 f2 f2 f2 f2 ==================================================================