================================================================== BUG: KASAN: use-after-free in __list_del_entry_valid+0xf1/0x100 lib/list_debug.c:51 Read of size 8 at addr ffff8801b27c7c70 by task syz-executor0/6767 CPU: 1 PID: 6767 Comm: syz-executor0 Not tainted 4.20.0-rc1-next-20181109+ #110 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+0x244/0x39d lib/dump_stack.c:113 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 __list_del_entry_valid+0xf1/0x100 lib/list_debug.c:51 __list_del_entry include/linux/list.h:117 [inline] list_del_init include/linux/list.h:159 [inline] __locks_delete_block fs/locks.c:683 [inline] locks_delete_block+0xce/0x3d0 fs/locks.c:716 locks_mandatory_area+0x48b/0x6a0 fs/locks.c:1398 locks_verify_truncate include/linux/fs.h:2361 [inline] do_sys_ftruncate+0x4b2/0x550 fs/open.c:190 __do_sys_ftruncate fs/open.c:204 [inline] __se_sys_ftruncate fs/open.c:202 [inline] __x64_sys_ftruncate+0x59/0x80 fs/open.c:202 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f4319e97c78 EFLAGS: 00000246 ORIG_RAX: 000000000000004d RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457569 RDX: 0000000000000000 RSI: 0000000000000039 RDI: 0000000000000004 RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f4319e986d4 R13: 00000000004bde51 R14: 00000000004cd048 R15: 00000000ffffffff The buggy address belongs to the page: page:ffffea0006c9f1c0 count:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x2fffc0000000000() raw: 02fffc0000000000 0000000000000000 ffffffff06c90101 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801b27c7b00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8801b27c7b80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff8801b27c7c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8801b27c7c80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8801b27c7d00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================