================================================================== BUG: KASAN: use-after-free in leaf_paste_in_buffer+0x615/0xab0 fs/reiserfs/lbalance.c:-1 Read of size 192 at addr ffff888061b88fa0 by task syz-executor.1/4820 CPU: 0 PID: 4820 Comm: syz-executor.1 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: 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 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+0x85f/0xe00 fs/reiserfs/lbalance.c:726 leaf_shift_left+0xb9/0x450 fs/reiserfs/lbalance.c:750 balance_leaf_paste_left_whole fs/reiserfs/do_balan.c:560 [inline] balance_leaf_paste_left fs/reiserfs/do_balan.c:594 [inline] balance_leaf_left fs/reiserfs/do_balan.c:613 [inline] balance_leaf+0x2f9d/0x10ec0 fs/reiserfs/do_balan.c:1409 do_balance+0x318/0x930 fs/reiserfs/do_balan.c:1888 reiserfs_paste_into_item+0x6dd/0x810 fs/reiserfs/stree.c:2159 reiserfs_get_block+0x1c3a/0x42a0 fs/reiserfs/inode.c:1077 __block_write_begin_int+0x565/0x15d0 fs/buffer.c:2012 reiserfs_write_begin+0x34b/0x810 fs/reiserfs/inode.c:2790 generic_perform_write+0x2b6/0x550 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+0x745/0xd60 fs/read_write.c:594 ksys_write+0x152/0x260 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: 0033:0x7f2291a19079 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:00007f2290daa0b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f2291b57f80 RCX: 00007f2291a19079 RDX: 000000000208e24b RSI: 00000000200001c0 RDI: 0000000000000005 RBP: 00007f2291a7a498 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f2291b57f80 R15: 00007ffda8a77ba8 The buggy address belongs to the page: page:ffffea000186e200 refcount:2 mapcount:0 mapping:ffff88801dae9470 index:0x27a pfn:0x61b88 memcg:ffff888065dd0000 aops:def_blk_aops ino:700001 flags: 0xfff00000002032(referenced|lru|active|private|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000002032 ffffea00018ab488 ffffea00018540c8 ffff88801dae9470 raw: 000000000000027a ffff8880724a7bc8 00000002ffffffff ffff888065dd0000 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 4820, ts 104918233008, free_ts 104781969657 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1bbd/0x1ca0 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+0x9b6/0xf10 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+0x247/0xb60 fs/buffer.c:1336 sb_getblk include/linux/buffer_head.h:361 [inline] get_empty_nodes+0x56a/0x920 fs/reiserfs/fix_node.c:890 fix_nodes+0x1ebc/0x8340 fs/reiserfs/fix_node.c:2662 reiserfs_paste_into_item+0x60b/0x810 fs/reiserfs/stree.c:2130 reiserfs_get_block+0x1c3a/0x42a0 fs/reiserfs/inode.c:1077 __block_write_begin_int+0x565/0x15d0 fs/buffer.c:2012 reiserfs_write_begin+0x34b/0x810 fs/reiserfs/inode.c:2790 generic_perform_write+0x2b6/0x550 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+0x745/0xd60 fs/read_write.c:594 ksys_write+0x152/0x260 fs/read_write.c:647 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+0x119/0x820 mm/page_alloc.c:3433 release_pages+0x186c/0x1be0 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+0x115/0x3b0 kernel/fork.c:1127 exit_mm+0x588/0x6e0 kernel/exit.c:550 do_exit+0x5a9/0x20c0 kernel/exit.c:870 do_group_exit+0x12e/0x300 kernel/exit.c:997 __do_sys_exit_group kernel/exit.c:1008 [inline] __se_sys_exit_group kernel/exit.c:1006 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006 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: ffff888061b88f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888061b88f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888061b89000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff888061b89080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888061b89100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 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