================================================================== BUG: KASAN: use-after-free in leaf_paste_in_buffer+0x615/0xab0 fs/reiserfs/lbalance.c:-1 Read of size 48 at addr ffff8880619d5ff0 by task syz-executor.2/5638 CPU: 0 PID: 5638 Comm: syz-executor.2 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: 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_left fs/reiserfs/do_balan.c:616 [inline] balance_leaf+0x13db/0x10e60 fs/reiserfs/do_balan.c:1409 do_balance+0x2fa/0x930 fs/reiserfs/do_balan.c:1888 reiserfs_insert_item+0xa4f/0xbb0 fs/reiserfs/stree.c:2261 reiserfs_get_block+0x1a32/0x4100 fs/reiserfs/inode.c:876 __block_write_begin_int+0x54e/0x15a0 fs/buffer.c:2012 reiserfs_write_begin+0x34b/0x810 fs/reiserfs/inode.c:2790 generic_perform_write+0x2aa/0x530 mm/filemap.c:3785 __generic_file_write_iter+0x25f/0x4e0 mm/filemap.c:3912 generic_file_write_iter+0xa6/0x1b0 mm/filemap.c:3944 call_write_iter include/linux/fs.h:2173 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x712/0xd00 fs/read_write.c:594 ksys_write+0x14d/0x250 fs/read_write.c:647 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: 0033:0x7f23a09e7ae9 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:00007f239fd690c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f23a0b06f80 RCX: 00007f23a09e7ae9 RDX: 000000000000000f RSI: 0000000020000100 RDI: 0000000000000005 RBP: 00007f23a0a3347a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f23a0b06f80 R15: 00007ffd8b6b1eb8 The buggy address belongs to the page: page:ffffea0001867540 refcount:2 mapcount:0 mapping:ffff88801c6c66b0 index:0x214 pfn:0x619d5 memcg:ffff88807a2d8000 aops:def_blk_aops ino:700002 flags: 0xfff00000002032(referenced|lru|active|private|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000002032 ffffea00003a8948 ffff888078a85030 ffff88801c6c66b0 raw: 0000000000000214 ffff888074bce9f8 00000002ffffffff ffff88807a2d8000 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 5638, ts 148027213609, free_ts 148001830630 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:5487 __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:3470 [inline] open_last_lookups fs/namei.c:3540 [inline] path_openat+0x11e1/0x2f30 fs/namei.c:3747 do_filp_open+0x1b3/0x3e0 fs/namei.c:3777 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_list+0x122/0x7e0 mm/page_alloc.c:3433 release_pages+0x184b/0x1bb0 mm/swap.c:963 __pagevec_release+0x6d/0xe0 mm/swap.c:983 pagevec_release include/linux/pagevec.h:81 [inline] truncate_inode_pages_range+0x2f3/0xef0 mm/truncate.c:329 truncate_inode_pages mm/truncate.c:425 [inline] truncate_pagecache mm/truncate.c:735 [inline] truncate_setsize+0xb9/0xe0 mm/truncate.c:760 reiserfs_setattr+0xa9a/0x1010 fs/reiserfs/inode.c:3408 notify_change+0xbcd/0xee0 fs/attr.c:505 do_truncate+0x197/0x220 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 Memory state around the buggy address: ffff8880619d5f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880619d5f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880619d6000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8880619d6080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880619d6100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================