loop4: detected capacity change from 0 to 128
VFS: Found a Xenix FS (block size = 1024) on device loop4
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BUG: KASAN: use-after-free in sysv_new_inode+0xd8c/0xf04 fs/sysv/ialloc.c:153
Read of size 2 at addr ffff0000fa4d41ce by task syz.4.204/5010

CPU: 0 PID: 5010 Comm: syz.4.204 Not tainted 6.1.135-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call trace:
 dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106
 print_address_description+0x88/0x220 mm/kasan/report.c:316
 print_report+0x50/0x68 mm/kasan/report.c:427
 kasan_report+0xa8/0x100 mm/kasan/report.c:531
 __asan_report_load2_noabort+0x2c/0x38 mm/kasan/report_generic.c:349
 sysv_new_inode+0xd8c/0xf04 fs/sysv/ialloc.c:153
 sysv_mkdir+0x44/0x138 fs/sysv/namei.c:121
 vfs_mkdir+0x314/0x4d4 fs/namei.c:4106
 do_mkdirat+0x1b4/0x3e0 fs/namei.c:4131
 __do_sys_mkdirat fs/namei.c:4146 [inline]
 __se_sys_mkdirat fs/namei.c:4144 [inline]
 __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4144
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

The buggy address belongs to the physical page:
page:00000000b5c3d3f6 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x13a4d4
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000fa4d4080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000fa4d4100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff0000fa4d4180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff0000fa4d4200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000fa4d4280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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