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BUG: KASAN: use-after-free in sysv_new_inode+0x107e/0x1210 fs/sysv/ialloc.c:153
Read of size 2 at addr ffff888047a991ce by task syz.0.58/3821

CPU: 0 PID: 3821 Comm: syz.0.58 Not tainted 6.1.97-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
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
 lookup_open fs/namei.c:3484 [inline]
 open_last_lookups fs/namei.c:3552 [inline]
 path_openat+0x12f1/0x2e60 fs/namei.c:3782
 do_filp_open+0x230/0x480 fs/namei.c:3812
 do_sys_openat2+0x13b/0x500 fs/open.c:1318
 do_sys_open fs/open.c:1334 [inline]
 __do_sys_openat fs/open.c:1350 [inline]
 __se_sys_openat fs/open.c:1345 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1345
 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: 0033:0x7fd3ae375bd9
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:00007fd3af0d6048 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fd3ae504110 RCX: 00007fd3ae375bd9
RDX: 00000000000026e1 RSI: 00000000200000c0 RDI: ffffffffffffff9c
RBP: 00007fd3ae3e4e60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fd3ae504110 R15: 00007ffe0b249568
 </TASK>

The buggy address belongs to the physical page:
page:ffffea00011ea640 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x47a99
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 dead000000000100 dead000000000122 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 3703, tgid 3700 (syz.2.25), ts 193598958947, free_ts 206949356641
 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+0x322e/0x33b0 mm/page_alloc.c:4283
 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5551
 folio_alloc+0x1a/0x50 mm/mempolicy.c:2292
 filemap_alloc_folio+0xda/0x4f0 mm/filemap.c:971
 do_read_cache_folio+0x2a7/0x810 mm/filemap.c:3562
 do_read_cache_page+0x32/0x220 mm/filemap.c:3640
 read_mapping_page include/linux/pagemap.h:791 [inline]
 dir_get_page fs/sysv/dir.c:58 [inline]
 sysv_find_entry+0x1b3/0x420 fs/sysv/dir.c:146
 sysv_inode_by_name+0x94/0x1f0 fs/sysv/dir.c:360
 sysv_lookup+0x63/0xe0 fs/sysv/namei.c:38
 lookup_open fs/namei.c:3462 [inline]
 open_last_lookups fs/namei.c:3552 [inline]
 path_openat+0x10fb/0x2e60 fs/namei.c:3782
 do_filp_open+0x230/0x480 fs/namei.c:3812
 do_sys_openat2+0x13b/0x500 fs/open.c:1318
 do_sys_open fs/open.c:1334 [inline]
 __do_sys_openat fs/open.c:1350 [inline]
 __se_sys_openat fs/open.c:1345 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1345
 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:3362
 free_unref_page_list+0x663/0x900 mm/page_alloc.c:3503
 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]
 truncate_inode_pages_range+0x48a/0x1340 mm/truncate.c:372
 sysv_evict_inode+0x27/0x110 fs/sysv/inode.c:292
 evict+0x2a4/0x620 fs/inode.c:666
 __dentry_kill+0x436/0x650 fs/dcache.c:607
 dentry_kill+0xbb/0x290
 dput+0xfb/0x1d0 fs/dcache.c:914
 shrink_dcache_for_umount+0x79/0x120 fs/dcache.c:1700
 generic_shutdown_super+0x63/0x340 fs/super.c:473
 kill_block_super+0x7a/0xe0 fs/super.c:1459
 deactivate_locked_super+0xa0/0x110 fs/super.c:332
 cleanup_mnt+0x490/0x520 fs/namespace.c:1186
 task_work_run+0x246/0x300 kernel/task_work.c:179

Memory state around the buggy address:
 ffff888047a99080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888047a99100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888047a99180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff888047a99200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888047a99280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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