================================================================== BUG: KASAN: use-after-free in leaf_paste_entries+0xe32/0x10c0 fs/reiserfs/lbalance.c:1351 Read of size 2 at addr ffff88805b950078 by task syz.0.1/4307 CPU: 1 PID: 4307 Comm: syz.0.1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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 leaf_paste_entries+0xe32/0x10c0 fs/reiserfs/lbalance.c:1351 leaf_copy_dir_entries+0x62b/0x8f0 fs/reiserfs/lbalance.c:119 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 vfs_truncate+0x262/0x2f0 fs/open.c:111 do_sys_truncate+0xdc/0x190 fs/open.c:134 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: 0033:0x7ff67e83d749 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:00007ff67caa4038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 00007ff67ea93fa0 RCX: 00007ff67e83d749 RDX: 0000000000000000 RSI: 00000000000000c9 RDI: 0000200000000080 RBP: 00007ff67e8c1f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff67ea94038 R14: 00007ff67ea93fa0 R15: 00007ffceaabae28 The buggy address belongs to the page: page:ffffea00016e5400 refcount:0 mapcount:0 mapping:0000000000000000 index:0x100 pfn:0x5b950 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000000100 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 0x8(__GFP_MOVABLE), pid 1, ts 10941399309, free_ts 11793898132 split_map_pages+0x277/0x4c0 mm/compaction.c:99 isolate_freepages_range+0x3dd/0x430 mm/compaction.c:749 alloc_contig_range+0x97e/0xcd0 mm/page_alloc.c:9280 __alloc_contig_pages mm/page_alloc.c:9304 [inline] alloc_contig_pages+0x390/0x490 mm/page_alloc.c:9384 debug_vm_pgtable_alloc_huge_page+0xbf/0x110 mm/debug_vm_pgtable.c:1090 init_args+0xb3a/0xdd0 mm/debug_vm_pgtable.c:1212 debug_vm_pgtable+0x42/0x370 mm/debug_vm_pgtable.c:1250 do_one_initcall+0x1ee/0x680 init/main.c:1316 do_initcall_level+0x137/0x1f0 init/main.c:1389 do_initcalls+0x4b/0x90 init/main.c:1405 kernel_init_freeable+0x3ce/0x560 init/main.c:1629 kernel_init+0x19/0x1b0 init/main.c:1520 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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 free_contig_range+0x96/0xf0 mm/page_alloc.c:9406 destroy_args+0x100/0xa20 mm/debug_vm_pgtable.c:1018 debug_vm_pgtable+0x318/0x370 mm/debug_vm_pgtable.c:1336 do_one_initcall+0x1ee/0x680 init/main.c:1316 do_initcall_level+0x137/0x1f0 init/main.c:1389 do_initcalls+0x4b/0x90 init/main.c:1405 kernel_init_freeable+0x3ce/0x560 init/main.c:1629 kernel_init+0x19/0x1b0 init/main.c:1520 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Memory state around the buggy address: ffff88805b94ff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88805b94ff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88805b950000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88805b950080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88805b950100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================