loop3: detected capacity change from 0 to 128
VFS: Found a Xenix FS (block size = 1024) on device loop3
==================================================================
BUG: KASAN: use-after-free in sysv_new_inode+0x10b4/0x1240 fs/sysv/ialloc.c:153
Read of size 2 at addr ffff88805cc561ce by task syz.3.27/4385

CPU: 1 PID: 4385 Comm: syz.3.27 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 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+0x10b4/0x1240 fs/sysv/ialloc.c:153
 sysv_symlink+0x9b/0x150 fs/sysv/namei.c:80
 vfs_symlink+0x247/0x3d0 fs/namei.c:4437
 do_symlinkat+0x1be/0x6c0 fs/namei.c:4466
 __do_sys_symlink fs/namei.c:4488 [inline]
 __se_sys_symlink fs/namei.c:4486 [inline]
 __x64_sys_symlink+0x7a/0x90 fs/namei.c:4486
 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: 0033:0x7f16d178d749
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:00007f16cf9f4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 00007f16d19e3fa0 RCX: 00007f16d178d749
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000200000000200
RBP: 00007f16d1811f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f16d19e4038 R14: 00007f16d19e3fa0 R15: 00007fffe955f8e8
 </TASK>

The buggy address belongs to the page:
page:ffffea0001731580 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x5cc56
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea00017315c8 ffffea0001731548 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 0x1100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), pid 4376, ts 68916957869, free_ts 69043281066
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487
 alloc_pages_vma+0x393/0x7c0 mm/mempolicy.c:2146
 wp_page_copy+0x206/0x1fd0 mm/memory.c:3051
 handle_pte_fault mm/memory.c:4668 [inline]
 __handle_mm_fault mm/memory.c:4785 [inline]
 handle_mm_fault+0x1ec7/0x43b0 mm/memory.c:4883
 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1357
 handle_page_fault arch/x86/mm/fault.c:1445 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1501
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
 __put_user_nocheck_4+0x3/0x11
 ____sys_recvmsg+0x35d/0x580 net/socket.c:2678
 ___sys_recvmsg+0x1af/0x4f0 net/socket.c:2707
 do_recvmmsg+0x344/0x7a0 net/socket.c:2801
 __sys_recvmmsg net/socket.c:2880 [inline]
 __do_sys_recvmmsg net/socket.c:2903 [inline]
 __se_sys_recvmmsg net/socket.c:2896 [inline]
 __x64_sys_recvmmsg+0x18d/0x240 net/socket.c:2896
 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
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+0x122/0x7e0 mm/page_alloc.c:3433
 shrink_page_list+0x5ed1/0x6b60 mm/vmscan.c:1818
 reclaim_pages+0x734/0x9a0 mm/vmscan.c:2424
 madvise_cold_or_pageout_pte_range+0x169c/0x1ee0 mm/madvise.c:478
 walk_pmd_range mm/pagewalk.c:128 [inline]
 walk_pud_range mm/pagewalk.c:205 [inline]
 walk_p4d_range mm/pagewalk.c:240 [inline]
 walk_pgd_range+0xbbc/0x13c0 mm/pagewalk.c:277
 __walk_page_range+0x133/0x5a0 mm/pagewalk.c:379
 walk_page_range+0x387/0x520 mm/pagewalk.c:477
 madvise_pageout_page_range mm/madvise.c:531 [inline]
 madvise_pageout mm/madvise.c:568 [inline]
 madvise_vma mm/madvise.c:998 [inline]
 do_madvise+0x1748/0x2b60 mm/madvise.c:1207
 __do_sys_madvise mm/madvise.c:1233 [inline]
 __se_sys_madvise mm/madvise.c:1231 [inline]
 __x64_sys_madvise+0xa2/0xb0 mm/madvise.c:1231
 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:
 ffff88805cc56080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805cc56100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88805cc56180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff88805cc56200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88805cc56280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================