REISERFS (device loop2): Using tea hash to sort names
REISERFS (device loop2): Created .reiserfs_priv - reserved for xattr storage.
==================================================================
BUG: KASAN: use-after-free in leaf_paste_in_buffer+0x615/0xab0 fs/reiserfs/lbalance.c:-1
Read of size 48 at addr ffff888058897ff0 by task syz.2.285/5736

CPU: 0 PID: 5736 Comm: syz.2.285 Not tainted 5.15.182-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x27b/0x290 mm/kasan/generic.c:189
 memcpy+0x25/0x60 mm/kasan/shadow.c:65
 leaf_paste_in_buffer+0x615/0xab0 fs/reiserfs/lbalance.c:-1
 leaf_copy_dir_entries+0x56c/0x8f0 fs/reiserfs/lbalance.c:108
 leaf_copy_boundary_item+0xb8c/0x2190 fs/reiserfs/lbalance.c:168
 leaf_copy_items fs/reiserfs/lbalance.c:551 [inline]
 leaf_move_items+0x84a/0xde0 fs/reiserfs/lbalance.c:726
 leaf_shift_left+0xb9/0x450 fs/reiserfs/lbalance.c:750
 balance_leaf_when_delete_left fs/reiserfs/do_balan.c:194 [inline]
 balance_leaf_when_delete fs/reiserfs/do_balan.c:272 [inline]
 balance_leaf+0x1dbd/0x10e60 fs/reiserfs/do_balan.c:1393
 do_balance+0x2fa/0x930 fs/reiserfs/do_balan.c:1888
 reiserfs_delete_solid_item+0x8b1/0xec0 fs/reiserfs/stree.c:1462
 remove_save_link+0x256/0x3c0 fs/reiserfs/super.c:540
 reiserfs_truncate_file+0x781/0xdc0 fs/reiserfs/inode.c:2330
 reiserfs_setattr+0xaa7/0x1010 fs/reiserfs/inode.c:3409
 notify_change+0xbcd/0xee0 fs/attr.c:505
 do_truncate+0x197/0x220 fs/open.c:65
 handle_truncate fs/namei.c:3265 [inline]
 do_open fs/namei.c:3612 [inline]
 path_openat+0x28af/0x2f30 fs/namei.c:3742
 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769
 do_sys_openat2+0x142/0x4a0 fs/open.c:1253
 do_sys_open fs/open.c:1269 [inline]
 __do_sys_creat fs/open.c:1345 [inline]
 __se_sys_creat fs/open.c:1339 [inline]
 __x64_sys_creat+0x8c/0xb0 fs/open.c:1339
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fd2d3491969
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:00007fd2d12f9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007fd2d36b8fa0 RCX: 00007fd2d3491969
RDX: 0000000000000000 RSI: ecf86c37d53049cc RDI: 0000200000000280
RBP: 00007fd2d3513ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd2d36b8fa0 R15: 00007ffcca5afa78
 </TASK>

The buggy address belongs to the page:
page:ffffea00016225c0 refcount:3 mapcount:0 mapping:ffff888016c97270 index:0x216 pfn:0x58897
memcg:ffff88807b18c000
aops:def_blk_aops ino:700002
flags: 0xfff00000002022(referenced|active|private|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002022 0000000000000000 dead000000000122 ffff888016c97270
raw: 0000000000000216 ffff8880747bf488 00000003ffffffff ffff88807b18c000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Movable, gfp_mask 0x108c48(GFP_NOFS|__GFP_NOFAIL|__GFP_HARDWALL|__GFP_MOVABLE), pid 5736, ts 184352579100, free_ts 184336891439
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5466
 __page_cache_alloc+0xd2/0x3f0 mm/filemap.c:1022
 pagecache_get_page+0x986/0xef0 mm/filemap.c:1940
 find_or_create_page include/linux/pagemap.h:420 [inline]
 grow_dev_page fs/buffer.c:949 [inline]
 grow_buffers fs/buffer.c:1014 [inline]
 __getblk_slow fs/buffer.c:1041 [inline]
 __getblk_gfp+0x249/0xb70 fs/buffer.c:1336
 sb_getblk include/linux/buffer_head.h:361 [inline]
 get_empty_nodes+0x511/0x8c0 fs/reiserfs/fix_node.c:890
 fix_nodes+0x1e69/0x82d0 fs/reiserfs/fix_node.c:2662
 reiserfs_insert_item+0x973/0xbb0 fs/reiserfs/stree.c:2240
 reiserfs_new_inode+0xf84/0x1860 fs/reiserfs/inode.c:2062
 reiserfs_create+0x3ba/0x680 fs/reiserfs/namei.c:668
 lookup_open fs/namei.c:3462 [inline]
 open_last_lookups fs/namei.c:3532 [inline]
 path_openat+0x11e1/0x2f30 fs/namei.c:3739
 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769
 do_sys_openat2+0x142/0x4a0 fs/open.c:1253
 do_sys_open fs/open.c:1269 [inline]
 __do_sys_openat fs/open.c:1285 [inline]
 __se_sys_openat fs/open.c:1280 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1280
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 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+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x94/0x280 mm/page_alloc.c:3396
 io_buffer_unmap+0xce/0x260 io_uring/io_uring.c:8914
 __io_sqe_buffers_unregister+0x8e/0x2b0 io_uring/io_uring.c:8933
 io_ring_ctx_free io_uring/io_uring.c:9384 [inline]
 io_ring_exit_work+0x7fc/0x1180 io_uring/io_uring.c:9577
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Memory state around the buggy address:
 ffff888058897f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888058897f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888058898000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888058898080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888058898100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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