erofs: (device loop3): erofs_find_target_block: corrupted dir block 8200 @ nid 36
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BUG: KASAN: slab-out-of-bounds in memcpy_to_page include/linux/highmem.h:427 [inline]
BUG: KASAN: slab-out-of-bounds in z_erofs_transform_plain+0x38c/0x460 fs/erofs/decompressor.c:346
Read of size 4095 at addr ffff88805f18f400 by task syz.3.146/6455

CPU: 1 PID: 6455 Comm: syz.3.146 Not tainted 6.6.95-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xac/0x230 mm/kasan/report.c:475
 kasan_report+0x117/0x150 mm/kasan/report.c:588
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x288/0x290 mm/kasan/generic.c:187
 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105
 memcpy_to_page include/linux/highmem.h:427 [inline]
 z_erofs_transform_plain+0x38c/0x460 fs/erofs/decompressor.c:346
 z_erofs_decompress_pcluster fs/erofs/zdata.c:1290 [inline]
 z_erofs_decompress_queue+0x16fb/0x2650 fs/erofs/zdata.c:1371
 z_erofs_runqueue+0x18a3/0x19d0 fs/erofs/zdata.c:1759
 z_erofs_readahead+0xa7c/0xd50 fs/erofs/zdata.c:1888
 read_pages+0x177/0x840 mm/readahead.c:160
 page_cache_ra_unbounded+0x692/0x770 mm/readahead.c:269
 do_page_cache_ra mm/readahead.c:299 [inline]
 force_page_cache_ra+0x2c1/0x320 mm/readahead.c:330
 force_page_cache_readahead mm/internal.h:175 [inline]
 generic_fadvise+0x44f/0x730 mm/fadvise.c:106
 vfs_fadvise mm/fadvise.c:185 [inline]
 ksys_fadvise64_64 mm/fadvise.c:199 [inline]
 __do_sys_fadvise64 mm/fadvise.c:214 [inline]
 __se_sys_fadvise64 mm/fadvise.c:212 [inline]
 __x64_sys_fadvise64+0x140/0x180 mm/fadvise.c:212
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f72f558e929
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:00007f72f643e038 EFLAGS: 00000246 ORIG_RAX: 00000000000000dd
RAX: ffffffffffffffda RBX: 00007f72f57b5fa0 RCX: 00007f72f558e929
RDX: 0000000000000007 RSI: 000000000000aa1f RDI: 0000000000000004
RBP: 00007f72f5610b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f72f57b5fa0 R15: 00007fff7b5672c8
 </TASK>

The buggy address belongs to the physical page:
page:ffffea00017c63c0 refcount:3 mapcount:0 mapping:ffff88805eb787c8 index:0x1 pfn:0x5f18f
memcg:ffff88801df22000
aops:z_erofs_cache_aops ino:0
flags: 0xfff00000008008(uptodate|private|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000008008 0000000000000000 dead000000000122 ffff88805eb787c8
raw: 0000000000000001 ffff88805b108000 00000003ffffffff ffff88801df22000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x192840(GFP_NOWAIT|__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 6455, tgid 6454 (syz.3.146), ts 106680293804, free_ts 106119141544
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
 prep_new_page mm/page_alloc.c:1561 [inline]
 get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
 z_erofs_bind_cache fs/erofs/zdata.c:599 [inline]
 z_erofs_pcluster_begin fs/erofs/zdata.c:883 [inline]
 z_erofs_do_read_page+0x20c0/0x3680 fs/erofs/zdata.c:1018
 z_erofs_read_folio+0x213/0x540 fs/erofs/zdata.c:1839
 filemap_read_folio+0x167/0x760 mm/filemap.c:2420
 do_read_cache_folio+0x470/0x7e0 mm/filemap.c:3789
 erofs_bread+0x16f/0x630 fs/erofs/data.c:48
 erofs_find_target_block fs/erofs/namei.c:103 [inline]
 erofs_namei+0x28c/0xf00 fs/erofs/namei.c:177
 erofs_lookup+0x135/0x310 fs/erofs/namei.c:206
 lookup_open fs/namei.c:3466 [inline]
 open_last_lookups fs/namei.c:3556 [inline]
 path_openat+0x10b8/0x3190 fs/namei.c:3786
 do_filp_open+0x1c5/0x3d0 fs/namei.c:3816
 do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
 do_sys_open fs/open.c:1434 [inline]
 __do_sys_openat fs/open.c:1450 [inline]
 __se_sys_openat fs/open.c:1445 [inline]
 __x64_sys_openat+0x139/0x160 fs/open.c:1445
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 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:1154 [inline]
 free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
 vfree+0x1a6/0x320 mm/vmalloc.c:2860
 delayed_vfree_work+0x55/0x80 mm/vmalloc.c:2780
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293

Memory state around the buggy address:
 ffff88805f18ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805f190000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805f190080: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc 00
                                        ^
 ffff88805f190100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805f190180: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc 00 00
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