VFS: Found a Xenix FS (block size = 1024) on device loop0
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BUG: KASAN: out-of-bounds in sysv_new_inode+0x1062/0x11f0 fs/sysv/ialloc.c:153
Read of size 2 at addr ffff88805d4331ce by task syz.0.15/4305

CPU: 0 PID: 4305 Comm: syz.0.15 Not tainted 5.15.175-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+0x1e3/0x2d0 lib/dump_stack.c:106
 print_address_description+0x63/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x16b/0x1c0 mm/kasan/report.c:451
 sysv_new_inode+0x1062/0x11f0 fs/sysv/ialloc.c:153
 sysv_mknod+0x4a/0xe0 fs/sysv/namei.c:53
 vfs_mknod+0x444/0x4d0 fs/namei.c:3944
 do_mknodat+0x392/0x690
 __do_sys_mknodat fs/namei.c:4022 [inline]
 __se_sys_mknodat fs/namei.c:4019 [inline]
 __x64_sys_mknodat+0xa5/0xc0 fs/namei.c:4019
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f587cc01d29
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:00007f587aa72038 EFLAGS: 00000246 ORIG_RAX: 0000000000000103
RAX: ffffffffffffffda RBX: 00007f587cdf1fa0 RCX: 00007f587cc01d29
RDX: 0000000000006004 RSI: 0000000020000000 RDI: ffffffffffffff9c
RBP: 00007f587cc7db08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000701 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f587cdf1fa0 R15: 00007fffec9bb958
 </TASK>

The buggy address belongs to the page:
page:ffffea0001750cc0 refcount:1 mapcount:0 mapping:ffff888028c21c30 index:0x6fa pfn:0x5d433
memcg:ffff88807a78c000
aops:shmem_aops ino:404 dentry name:"memfd:syzkaller"
flags: 0xfff0000008001e(referenced|uptodate|dirty|lru|swapbacked|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff0000008001e ffffea0001750c88 ffffea0001750588 ffff888028c21c30
raw: 00000000000006fa 0000000000000000 00000001ffffffff ffff88807a78c000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Movable, gfp_mask 0x1100cca(GFP_HIGHUSER_MOVABLE), pid 4297, ts 65520835465, free_ts 65019168924
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x3b78/0x3d40 mm/page_alloc.c:4192
 __alloc_pages+0x272/0x700 mm/page_alloc.c:5465
 alloc_pages_vma+0x39a/0x800 mm/mempolicy.c:2146
 shmem_alloc_page mm/shmem.c:1586 [inline]
 shmem_alloc_and_acct_page+0x4d1/0xd10 mm/shmem.c:1611
 shmem_getpage_gfp+0x17b1/0x3190 mm/shmem.c:1906
 shmem_getpage mm/shmem.c:151 [inline]
 shmem_write_begin+0xce/0x1a0 mm/shmem.c:2474
 generic_perform_write+0x2bf/0x5b0 mm/filemap.c:3785
 __generic_file_write_iter+0x243/0x4f0 mm/filemap.c:3912
 generic_file_write_iter+0xa7/0x1b0 mm/filemap.c:3944
 call_write_iter include/linux/fs.h:2174 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0xacd/0xe50 fs/read_write.c:594
 ksys_write+0x1a2/0x2c0 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 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+0xc34/0xcf0 mm/page_alloc.c:3317
 free_unref_page_list+0x1f7/0x8e0 mm/page_alloc.c:3433
 release_pages+0x1bb9/0x1f40 mm/swap.c:963
 __pagevec_release+0x80/0xf0 mm/swap.c:983
 pagevec_release include/linux/pagevec.h:81 [inline]
 shmem_undo_range+0x67a/0x1b50 mm/shmem.c:964
 shmem_truncate_range mm/shmem.c:1063 [inline]
 shmem_evict_inode+0x21b/0xa00 mm/shmem.c:1145
 evict+0x529/0x930 fs/inode.c:622
 __dentry_kill+0x436/0x650 fs/dcache.c:586
 dentry_kill+0xbb/0x290
 dput+0xd8/0x1a0 fs/dcache.c:893
 __fput+0x636/0x8e0 fs/file_table.c:288
 task_work_run+0x129/0x1a0 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0x6a3/0x2480 kernel/exit.c:874
 do_group_exit+0x144/0x310 kernel/exit.c:996
 __do_sys_exit_group kernel/exit.c:1007 [inline]
 __se_sys_exit_group kernel/exit.c:1005 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1005
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80

Memory state around the buggy address:
 ffff88805d433080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805d433100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805d433180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                              ^
 ffff88805d433200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805d433280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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