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BUG: KASAN: use-after-free in sysv_new_inode+0xed4/0x1190 fs/sysv/ialloc.c:153
Read of size 2 at addr ffff888059e5d1ce by task syz-executor.1/9483

CPU: 1 PID: 9483 Comm: syz-executor.1 Not tainted 6.10.0-rc2-syzkaller-00097-g2df0193e62cf #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 sysv_new_inode+0xed4/0x1190 fs/sysv/ialloc.c:153
 sysv_mknod fs/sysv/namei.c:53 [inline]
 sysv_create+0x20/0xf0 fs/sysv/namei.c:67
 lookup_open.isra.0+0x10a1/0x13c0 fs/namei.c:3505
 open_last_lookups fs/namei.c:3574 [inline]
 path_openat+0x92f/0x29f0 fs/namei.c:3804
 do_filp_open+0x1dc/0x430 fs/namei.c:3834
 do_sys_openat2+0x17a/0x1e0 fs/open.c:1405
 do_sys_open fs/open.c:1420 [inline]
 __do_sys_creat fs/open.c:1496 [inline]
 __se_sys_creat fs/open.c:1490 [inline]
 __x64_sys_creat+0xcd/0x120 fs/open.c:1490
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff83c27cf69
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff83d0560c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007ff83c3b4050 RCX: 00007ff83c27cf69
RDX: 0000000000000000 RSI: ecf86c37d53049dc RDI: 0000000020000280
RBP: 00007ff83c2da6fe R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007ff83c3b4050 R15: 00007fff9e518f98
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xe71 pfn:0x59e5d
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea00010caac8 ffffea0001841c48 0000000000000000
raw: 0000000000000e71 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 0x100cca(GFP_HIGHUSER_MOVABLE), pid 19115, tgid 19114 (syz-executor.3), ts 1682729394681, free_ts 1684799474799
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1468
 prep_new_page mm/page_alloc.c:1476 [inline]
 get_page_from_freelist+0x136a/0x2df0 mm/page_alloc.c:3402
 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4660
 alloc_pages_mpol_noprof+0x275/0x610 mm/mempolicy.c:2265
 shmem_alloc_folio+0x114/0x150 mm/shmem.c:1628
 shmem_alloc_and_add_folio+0x14f/0x790 mm/shmem.c:1668
 shmem_get_folio_gfp+0x687/0x13d0 mm/shmem.c:2055
 shmem_get_folio mm/shmem.c:2160 [inline]
 shmem_write_begin+0x15a/0x360 mm/shmem.c:2743
 generic_perform_write+0x272/0x620 mm/filemap.c:4015
 shmem_file_write_iter+0x114/0x140 mm/shmem.c:2919
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0x6b6/0x1140 fs/read_write.c:590
 ksys_write+0x12f/0x260 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 19114 tgid 19114 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1088 [inline]
 free_unref_folios+0x991/0x1310 mm/page_alloc.c:2614
 folios_put_refs+0x487/0x6d0 mm/swap.c:1024
 folio_batch_release include/linux/pagevec.h:101 [inline]
 shmem_undo_range+0x5a1/0x1160 mm/shmem.c:1005
 shmem_truncate_range mm/shmem.c:1114 [inline]
 shmem_evict_inode+0x3a3/0xbb0 mm/shmem.c:1242
 evict+0x2ed/0x6c0 fs/inode.c:667
 iput_final fs/inode.c:1741 [inline]
 iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
 iput+0x5c/0x80 fs/inode.c:1757
 dentry_unlink_inode+0x295/0x480 fs/dcache.c:400
 __dentry_kill+0x1d0/0x600 fs/dcache.c:603
 dput.part.0+0x4b1/0x9b0 fs/dcache.c:845
 dput+0x1f/0x30 fs/dcache.c:835
 __fput+0x54e/0xbb0 fs/file_table.c:430
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa9b/0x2ba0 kernel/exit.c:874
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1023
 get_signal+0x2616/0x2710 kernel/signal.c:2909

Memory state around the buggy address:
 ffff888059e5d080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888059e5d100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888059e5d180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff888059e5d200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888059e5d280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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