loop0: detected capacity change from 0 to 128
VFS: Found a Xenix FS (block size = 1024) on device loop0
==================================================================
BUG: KASAN: use-after-free in sysv_new_inode+0x1105/0x1290 fs/sysv/ialloc.c:153
Read of size 2 at addr ffff888068daa1ce by task syz.0.19/5014

CPU: 0 PID: 5014 Comm: syz.0.19 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 sysv_new_inode+0x1105/0x1290 fs/sysv/ialloc.c:153
 sysv_mknod+0x4a/0xd0 fs/sysv/namei.c:53
 lookup_open fs/namei.c:3470 [inline]
 open_last_lookups fs/namei.c:3540 [inline]
 path_openat+0x120a/0x2fb0 fs/namei.c:3747
 do_filp_open+0x1df/0x400 fs/namei.c:3777
 do_sys_openat2+0x14b/0x500 fs/open.c:1255
 do_sys_open fs/open.c:1271 [inline]
 __do_sys_openat fs/open.c:1287 [inline]
 __se_sys_openat fs/open.c:1282 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1282
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7ff37377f3b9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff3729e6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ff3739adfa0 RCX: 00007ff37377f3b9
RDX: 000000000000275a RSI: 0000000020000080 RDI: ffffffffffffff9c
RBP: 00007ff37381016c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff3739adfa0 R15: 00007ffd4e51e528
 </TASK>

The buggy address belongs to the page:
page:ffffea0001a36a80 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x68daa
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001af4188 ffffea0001a3c288 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Movable, gfp_mask 0x1100cca(GFP_HIGHUSER_MOVABLE), pid 5003, ts 119030024114, free_ts 119049728352
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 alloc_pages_vma+0x2bc/0x790 mm/mempolicy.c:2146
 wp_page_copy+0x252/0x2090 mm/memory.c:3056
 handle_pte_fault mm/memory.c:4668 [inline]
 __handle_mm_fault mm/memory.c:4785 [inline]
 handle_mm_fault+0x1fbd/0x4440 mm/memory.c:4883
 do_user_addr_fault+0x494/0xc90 arch/x86/mm/fault.c:1355
 handle_page_fault arch/x86/mm/fault.c:1443 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page_list+0x119/0x830 mm/page_alloc.c:3433
 release_pages+0x185f/0x1bd0 mm/swap.c:963
 tlb_batch_pages_flush mm/mmu_gather.c:50 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:241 [inline]
 tlb_flush_mmu mm/mmu_gather.c:248 [inline]
 tlb_finish_mmu+0x1b4/0x370 mm/mmu_gather.c:371
 exit_mmap+0x3d0/0x640 mm/mmap.c:3218
 __mmput+0x115/0x390 kernel/fork.c:1128
 exit_mm+0x632/0x7b0 kernel/exit.c:551
 do_exit+0x5b8/0x2110 kernel/exit.c:871
 do_group_exit+0x12c/0x2f0 kernel/exit.c:998
 __do_sys_exit_group kernel/exit.c:1009 [inline]
 __se_sys_exit_group kernel/exit.c:1007 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1007
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

Memory state around the buggy address:
 ffff888068daa080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888068daa100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888068daa180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff888068daa200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888068daa280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================