VFS: Found a Xenix FS (block size = 1024) on device loop0
syz.0.1: 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: out-of-bounds in sysv_new_inode+0xfe4/0x1190 fs/sysv/ialloc.c:153
Read of size 2 at addr ffff888077ea41ce by task syz.0.1/5914

CPU: 0 UID: 0 PID: 5914 Comm: syz.0.1 Not tainted 6.14.0-rc7-syzkaller-00196-g88d324e69ea9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __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:408 [inline]
 print_report+0x16e/0x5b0 mm/kasan/report.c:521
 kasan_report+0x143/0x180 mm/kasan/report.c:634
 sysv_new_inode+0xfe4/0x1190 fs/sysv/ialloc.c:153
 sysv_mknod+0x4e/0xe0 fs/sysv/namei.c:53
 vfs_mknod+0x36d/0x3b0 fs/namei.c:4191
 do_mknodat+0x3ec/0x5b0
 __do_sys_mknod fs/namei.c:4274 [inline]
 __se_sys_mknod fs/namei.c:4272 [inline]
 __x64_sys_mknod+0x8c/0xa0 fs/namei.c:4272
 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: 0033:0x7f21a578d169
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:00007f21a6526038 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 00007f21a59a5fa0 RCX: 00007f21a578d169
RDX: 0000000000000000 RSI: 0000000000001ffa RDI: 0000200000000180
RBP: 00007f21a580e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f21a59a5fa0 R15: 00007ffe3bc4d258
 </TASK>

The buggy address belongs to the physical page:
page: refcount:3 mapcount:1 mapping:ffff88807887c040 index:0xc pfn:0x77ea4
memcg:ffff88801c2f4000
aops:ext4_da_aops ino:78c dentry name(?):"syz.MRWBV0"
flags: 0xfff00000004038(uptodate|dirty|lru|private|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000004038 ffffea0001e037c8 ffffea0001dfa948 ffff88807887c040
raw: 000000000000000c ffff88805b912658 0000000300000000 ffff88801c2f4000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Movable, gfp_mask 0x152c4a(GFP_NOFS|__GFP_HIGHMEM|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL|__GFP_MOVABLE), pid 5818, tgid 5818 (syz-executor), ts 85599473243, free_ts 85485571130
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551
 prep_new_page mm/page_alloc.c:1559 [inline]
 get_page_from_freelist+0x3651/0x37a0 mm/page_alloc.c:3477
 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4740
 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270
 alloc_frozen_pages_noprof mm/mempolicy.c:2341 [inline]
 alloc_pages_noprof+0x121/0x190 mm/mempolicy.c:2361
 folio_alloc_noprof+0x1e/0x30 mm/mempolicy.c:2371
 filemap_alloc_folio_noprof+0xe1/0x540 mm/filemap.c:1018
 ractl_alloc_folio mm/readahead.c:186 [inline]
 page_cache_ra_unbounded+0x36b/0x820 mm/readahead.c:270
 do_sync_mmap_readahead+0x499/0x970
 filemap_fault+0x8a9/0x1490 mm/filemap.c:3402
 __do_fault+0x135/0x390 mm/memory.c:4989
 do_shared_fault mm/memory.c:5473 [inline]
 do_fault mm/memory.c:5547 [inline]
 do_pte_missing mm/memory.c:4059 [inline]
 handle_pte_fault mm/memory.c:5888 [inline]
 __handle_mm_fault+0x2041/0x6ef0 mm/memory.c:6031
 handle_mm_fault+0x2c1/0x7e0 mm/memory.c:6200
 do_user_addr_fault arch/x86/mm/fault.c:1337 [inline]
 handle_page_fault arch/x86/mm/fault.c:1480 [inline]
 exc_page_fault+0x459/0x8b0 arch/x86/mm/fault.c:1538
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
page last free pid 5913 tgid 5913 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_folios+0xe2f/0x18a0 mm/page_alloc.c:2707
 folios_put_refs+0x76c/0x860 mm/swap.c:994
 free_pages_and_swap_cache+0x5c3/0x690 mm/swap_state.c:334
 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
 tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:389 [inline]
 tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:396
 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:488
 exit_mmap+0x52a/0xd40 mm/mmap.c:1297
 __mmput+0x115/0x410 kernel/fork.c:1356
 exit_mm+0x220/0x310 kernel/exit.c:570
 do_exit+0x9ad/0x2940 kernel/exit.c:925
 do_group_exit+0x207/0x2c0 kernel/exit.c:1087
 __do_sys_exit_group kernel/exit.c:1098 [inline]
 __se_sys_exit_group kernel/exit.c:1096 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096
 x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232
 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

Memory state around the buggy address:
 ffff888077ea4080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888077ea4100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888077ea4180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                                 ^
 ffff888077ea4200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888077ea4280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================