================================================================== BUG: KASAN: use-after-free in leaf_paste_in_buffer+0x571/0xc00 fs/reiserfs/lbalance.c:1043 Read of size 48 at addr ffff8880708feff0 by task syz.1.1521/13813 CPU: 0 PID: 13813 Comm: syz.1.1521 Not tainted 6.1.131-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0x15f/0x4f0 mm/kasan/report.c:427 kasan_report+0x136/0x160 mm/kasan/report.c:531 kasan_check_range+0x27f/0x290 mm/kasan/generic.c:189 memcpy+0x25/0x60 mm/kasan/shadow.c:65 leaf_paste_in_buffer+0x571/0xc00 fs/reiserfs/lbalance.c:1043 leaf_copy_dir_entries+0x719/0xc50 fs/reiserfs/lbalance.c:108 leaf_copy_boundary_item+0xbbe/0x21b0 fs/reiserfs/lbalance.c:168 leaf_copy_items fs/reiserfs/lbalance.c:551 [inline] leaf_move_items+0xc9c/0x1340 fs/reiserfs/lbalance.c:726 leaf_shift_left+0xba/0x430 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+0x228e/0x12510 fs/reiserfs/do_balan.c:1393 do_balance+0x309/0x8f0 fs/reiserfs/do_balan.c:1888 reiserfs_delete_solid_item+0xb7f/0x12d0 fs/reiserfs/stree.c:1462 remove_save_link+0x30c/0x540 fs/reiserfs/super.c:540 reiserfs_truncate_file+0x5d5/0x810 fs/reiserfs/inode.c:2322 reiserfs_setattr+0xc57/0x11c0 fs/reiserfs/inode.c:3395 notify_change+0xce3/0xfc0 fs/attr.c:499 do_truncate+0x21c/0x300 fs/open.c:65 vfs_truncate+0x2dd/0x3a0 fs/open.c:111 do_sys_truncate+0xda/0x190 fs/open.c:134 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7ff1db18d169 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:00007ff1dc0ac038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 00007ff1db3a5fa0 RCX: 00007ff1db18d169 RDX: 0000000000000000 RSI: 00000000003a6000 RDI: 0000400000000080 RBP: 00007ff1db20e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff1db3a5fa0 R15: 00007ffeb2926c18 The buggy address belongs to the physical page: page:ffffea0001c23f80 refcount:2 mapcount:0 mapping:ffff88801809d4f8 index:0x233 pfn:0x708fe memcg:ffff888053e40000 aops:def_blk_aops ino:700001 flags: 0xfff50000002052(referenced|lru|workingset|private|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff50000002052 ffffea0001c1b748 ffff888053e421f8 ffff88801809d4f8 raw: 0000000000000233 ffff888051d79bc8 00000002ffffffff ffff888053e40000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Movable, gfp_mask 0x148c48(GFP_NOFS|__GFP_NOFAIL|__GFP_COMP|__GFP_HARDWALL|__GFP_MOVABLE), pid 13813, tgid 13812 (syz.1.1521), ts 1307297862046, free_ts 1306655652364 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x3731/0x38d0 mm/page_alloc.c:4328 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5606 folio_alloc+0x1a/0x50 mm/mempolicy.c:2292 filemap_alloc_folio+0xda/0x4f0 mm/filemap.c:999 __filemap_get_folio+0x749/0xe80 mm/filemap.c:1993 pagecache_get_page+0x28/0x250 mm/folio-compat.c:110 find_or_create_page include/linux/pagemap.h:646 [inline] grow_dev_page fs/buffer.c:946 [inline] grow_buffers fs/buffer.c:1011 [inline] __getblk_slow fs/buffer.c:1038 [inline] __getblk_gfp+0x211/0xa20 fs/buffer.c:1333 sb_getblk include/linux/buffer_head.h:356 [inline] get_empty_nodes+0x8c1/0xd70 fs/reiserfs/fix_node.c:890 fix_nodes+0x2615/0x8c70 fs/reiserfs/fix_node.c:2662 reiserfs_paste_into_item+0x65d/0x880 fs/reiserfs/stree.c:2130 reiserfs_get_block+0x2259/0x5150 fs/reiserfs/inode.c:1069 __block_write_begin_int+0x544/0x1a30 fs/buffer.c:1991 reiserfs_write_begin+0x249/0x510 fs/reiserfs/inode.c:2775 generic_cont_expand_simple+0x187/0x2a0 fs/buffer.c:2347 reiserfs_setattr+0x606/0x11c0 fs/reiserfs/inode.c:3305 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x12a6/0x15b0 mm/page_alloc.c:3384 free_unref_page_list+0x663/0x900 mm/page_alloc.c:3525 release_pages+0x24c4/0x27a0 mm/swap.c:1035 __pagevec_release+0x80/0xf0 mm/swap.c:1055 pagevec_release include/linux/pagevec.h:71 [inline] folio_batch_release include/linux/pagevec.h:135 [inline] shmem_undo_range+0x865/0x2390 mm/shmem.c:946 shmem_truncate_range mm/shmem.c:1062 [inline] shmem_evict_inode+0x265/0xa60 mm/shmem.c:1171 evict+0x529/0x930 fs/inode.c:705 __dentry_kill+0x436/0x650 fs/dcache.c:611 dentry_kill+0xbb/0x290 dput+0xfb/0x1d0 fs/dcache.c:918 __fput+0x62e/0x8d0 fs/file_table.c:328 task_work_run+0x246/0x300 kernel/task_work.c:203 exit_task_work include/linux/task_work.h:39 [inline] do_exit+0xa6e/0x26a0 kernel/exit.c:871 do_group_exit+0x202/0x2b0 kernel/exit.c:1021 get_signal+0x16cb/0x17a0 kernel/signal.c:2871 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 Memory state around the buggy address: ffff8880708fef00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880708fef80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880708ff000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff8880708ff080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff8880708ff100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================