loop0: detected capacity change from 0 to 128 VFS: Found a Xenix FS (block size = 1024) on device loop0 syz.0.0: attempt to access beyond end of device loop0: rw=0, sector=6491536, nr_sectors = 2 limit=128 Buffer I/O error on dev loop0, logical block 3245768, async page read ================================================================== BUG: KASAN: use-after-free in sysv_new_inode+0xfc7/0x1160 fs/sysv/ialloc.c:153 Read of size 2 at addr ffff88804d3721ce by task syz.0.0/5315 CPU: 0 UID: 0 PID: 5315 Comm: syz.0.0 Not tainted 6.13.0-rc3-syzkaller-00193-ge9b8ffafd20a #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 sysv_new_inode+0xfc7/0x1160 fs/sysv/ialloc.c:153 sysv_mknod+0x4e/0xe0 fs/sysv/namei.c:53 lookup_open fs/namei.c:3649 [inline] open_last_lookups fs/namei.c:3748 [inline] path_openat+0x1c03/0x3590 fs/namei.c:3984 do_filp_open+0x27f/0x4e0 fs/namei.c:4014 do_sys_openat2+0x13e/0x1d0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_sys_open fs/open.c:1425 [inline] __se_sys_open fs/open.c:1421 [inline] __x64_sys_open+0x225/0x270 fs/open.c:1421 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f34c9f85d29 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f34cae1e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f34ca175fa0 RCX: 00007f34c9f85d29 RDX: 0000000000000000 RSI: 0000000000161b42 RDI: 0000000020000200 RBP: 00007f34ca001aa8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f34ca175fa0 R15: 00007fffcbb90e98 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4d372 flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff) raw: 04fff00000000000 ffffea000134dcc8 ffff88801fc44b30 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner info is not present (never set?) Memory state around the buggy address: ffff88804d372080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88804d372100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88804d372180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88804d372200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88804d372280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================