VFS: Found a Xenix FS (block size = 1024) on device loop2
syz.2.1223: attempt to access beyond end of device
loop2: rw=0, sector=6491536, nr_sectors = 2 limit=128
Buffer I/O error on dev loop2, logical block 3245768, async page read
==================================================================
BUG: KASAN: use-after-free in sysv_new_inode+0x107e/0x1210 fs/sysv/ialloc.c:153
Read of size 2 at addr ffff88804a8491ce by task syz.2.1223/9478

CPU: 1 PID: 9478 Comm: syz.2.1223 Not tainted 6.1.117-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:284 [inline]
 print_report+0x15f/0x4f0 mm/kasan/report.c:395
 kasan_report+0x136/0x160 mm/kasan/report.c:495
 sysv_new_inode+0x107e/0x1210 fs/sysv/ialloc.c:153
 sysv_mknod+0x4a/0xe0 fs/sysv/namei.c:53
 vfs_create+0x306/0x490 fs/namei.c:3184
 do_mknodat+0x338/0x5a0 fs/namei.c:4035
 __do_sys_mknodat fs/namei.c:4063 [inline]
 __se_sys_mknodat fs/namei.c:4060 [inline]
 __x64_sys_mknodat+0xa5/0xc0 fs/namei.c:4060
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f276277e719
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:00007f27635a9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000103
RAX: ffffffffffffffda RBX: 00007f2762935f80 RCX: 00007f276277e719
RDX: 0000000000008000 RSI: 0000000020000180 RDI: ffffffffffffff9c
RBP: 00007f27627f175e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000001004 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f2762935f80 R15: 00007fff76d31f48
 </TASK>

The buggy address belongs to the physical page:
page:ffffea00012a1240 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x4a849
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea00012a1288 ffffea00012a1208 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 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 9421, tgid 9420 (syz.2.1207), ts 604350413691, free_ts 608405867480
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2517
 prep_new_page mm/page_alloc.c:2524 [inline]
 get_page_from_freelist+0x3731/0x38d0 mm/page_alloc.c:4313
 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5589
 __folio_alloc+0xf/0x30 mm/page_alloc.c:5621
 vma_alloc_folio+0x486/0x990 mm/mempolicy.c:2243
 shmem_alloc_folio mm/shmem.c:1591 [inline]
 shmem_alloc_and_acct_folio+0x5a8/0xd50 mm/shmem.c:1615
 shmem_get_folio_gfp+0x13f0/0x3470 mm/shmem.c:1943
 shmem_fault+0x235/0x9c0 mm/shmem.c:2158
 __do_fault+0x136/0x4f0 mm/memory.c:4278
 do_read_fault mm/memory.c:4629 [inline]
 do_fault mm/memory.c:4758 [inline]
 handle_pte_fault mm/memory.c:5029 [inline]
 __handle_mm_fault mm/memory.c:5171 [inline]
 handle_mm_fault+0x3410/0x5340 mm/memory.c:5292
 faultin_page mm/gup.c:1009 [inline]
 __get_user_pages+0x4f3/0x1190 mm/gup.c:1233
 populate_vma_page_range+0x217/0x2b0 mm/gup.c:1590
 __mm_populate+0x275/0x440 mm/gup.c:1704
 mm_populate include/linux/mm.h:2801 [inline]
 vm_mmap_pgoff+0x22b/0x2d0 mm/util.c:525
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1444 [inline]
 free_pcp_prepare mm/page_alloc.c:1494 [inline]
 free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3369
 free_unref_page_list+0x663/0x900 mm/page_alloc.c:3510
 release_pages+0x2836/0x2b40 mm/swap.c:1055
 __pagevec_release+0x80/0xf0 mm/swap.c:1075
 pagevec_release include/linux/pagevec.h:71 [inline]
 folio_batch_release include/linux/pagevec.h:135 [inline]
 shmem_undo_range+0x865/0x2390 mm/shmem.c:946
 shmem_truncate_range mm/shmem.c:1062 [inline]
 shmem_evict_inode+0x265/0xa60 mm/shmem.c:1173
 evict+0x529/0x930 fs/inode.c:701
 __dentry_kill+0x436/0x650 fs/dcache.c:611
 dentry_kill+0xbb/0x290
 dput+0xfb/0x1d0 fs/dcache.c:918
 __fput+0x62e/0x8d0 fs/file_table.c:328
 task_work_run+0x246/0x300 kernel/task_work.c:203
 exit_task_work include/linux/task_work.h:39 [inline]
 do_exit+0xa73/0x26a0 kernel/exit.c:871
 do_group_exit+0x202/0x2b0 kernel/exit.c:1021
 get_signal+0x16f7/0x17d0 kernel/signal.c:2871
 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871

Memory state around the buggy address:
 ffff88804a849080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804a849100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88804a849180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff88804a849200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88804a849280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================