REISERFS (device loop0): checking transaction log (loop0)
REISERFS (device loop0): Using r5 hash to sort names
REISERFS (device loop0): using 3.5.x disk format
REISERFS (device loop0): Created .reiserfs_priv - reserved for xattr storage.
==================================================================
BUG: KASAN: out-of-bounds in leaf_paste_in_buffer+0x1e7/0xaf0 fs/reiserfs/lbalance.c:1017
Read of size 18446744073709551309 at addr ffff8880668fb000 by task syz-executor.0/4516

CPU: 0 PID: 4516 Comm: syz-executor.0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 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+0x235/0x290 mm/kasan/generic.c:189
 memmove+0x25/0x60 mm/kasan/shadow.c:54
 leaf_paste_in_buffer+0x1e7/0xaf0 fs/reiserfs/lbalance.c:1017
 balance_leaf_new_nodes_paste_whole fs/reiserfs/do_balan.c:1171 [inline]
 balance_leaf_new_nodes_paste fs/reiserfs/do_balan.c:1215 [inline]
 balance_leaf_new_nodes fs/reiserfs/do_balan.c:1246 [inline]
 balance_leaf+0x748f/0x10ec0 fs/reiserfs/do_balan.c:1450
 do_balance+0x318/0x930 fs/reiserfs/do_balan.c:1888
 reiserfs_paste_into_item+0x744/0x7f0 fs/reiserfs/stree.c:2159
 reiserfs_get_block+0x1c3d/0x4360 fs/reiserfs/inode.c:1077
 __block_write_begin_int+0x565/0x15d0 fs/buffer.c:2012
 reiserfs_write_begin+0x353/0x820 fs/reiserfs/inode.c:2790
 generic_cont_expand_simple+0xf0/0x1a0 fs/buffer.c:2362
 reiserfs_setattr+0x3f5/0x10d0 fs/reiserfs/inode.c:3319
 notify_change+0xbc6/0xee0 fs/attr.c:505
 do_truncate+0x1ac/0x240 fs/open.c:65
 do_sys_ftruncate+0x31b/0x3d0 fs/open.c:193
 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: 0033:0x7f35c5916079
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 d0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f35c4ca70b8 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 00007f35c5a54f80 RCX: 00007f35c5916079
RDX: 0000000000000000 RSI: 0000000002007fff RDI: 0000000000000005
RBP: 00007f35c5977498 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f35c5a54f80 R15: 00007ffd9de65728
 </TASK>

The buggy address belongs to the page:
page:ffffea00019a3ec0 refcount:3 mapcount:0 mapping:ffff88806e8c9e38 index:0x0 pfn:0x668fb
memcg:ffff888076158000
aops:reiserfs_address_space_operations ino:2 dentry name:"file2"
flags: 0xfff00000002011(locked|lru|private|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002011 ffff888074949020 ffff888074949020 ffff88806e8c9e38
raw: 0000000000000000 ffff888070c78488 00000003ffffffff ffff888076158000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Movable, gfp_mask 0x1101cca(GFP_HIGHUSER_MOVABLE|__GFP_WRITE), pid 4529, ts 64819214744, free_ts 64724351357
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 __page_cache_alloc+0xce/0x440 mm/filemap.c:1022
 pagecache_get_page+0x9b8/0xf20 mm/filemap.c:1940
 grab_cache_page_write_begin+0x5c/0xa0 mm/filemap.c:3739
 reiserfs_write_begin+0x156/0x820 fs/reiserfs/inode.c:2774
 generic_cont_expand_simple+0xf0/0x1a0 fs/buffer.c:2362
 reiserfs_setattr+0x3f5/0x10d0 fs/reiserfs/inode.c:3319
 notify_change+0xbc6/0xee0 fs/attr.c:505
 do_truncate+0x1ac/0x240 fs/open.c:65
 do_sys_ftruncate+0x31b/0x3d0 fs/open.c:193
 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_list+0x119/0x830 mm/page_alloc.c:3433
 release_pages+0x185f/0x1bd0 mm/swap.c:963
 tlb_batch_pages_flush mm/mmu_gather.c:50 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:241 [inline]
 tlb_flush_mmu mm/mmu_gather.c:248 [inline]
 tlb_finish_mmu+0x1b4/0x370 mm/mmu_gather.c:371
 exit_mmap+0x3d0/0x640 mm/mmap.c:3218
 __mmput+0x115/0x390 kernel/fork.c:1133
 exit_mm+0x632/0x7b0 kernel/exit.c:557
 do_exit+0x5b8/0x2110 kernel/exit.c:877
 do_group_exit+0x12c/0x2f0 kernel/exit.c:1004
 __do_sys_exit_group kernel/exit.c:1015 [inline]
 __se_sys_exit_group kernel/exit.c:1013 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1013
 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

Memory state around the buggy address:
 ffff8880668faf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880668faf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880668fb000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                   ^
 ffff8880668fb080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880668fb100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================