================================================================== BUG: KASAN: use-after-free in leaf_paste_in_buffer+0x615/0xab0 fs/reiserfs/lbalance.c:-1 Read of size 48 at addr ffff88805c5b8ff0 by task syz.1.367/6958 CPU: 0 PID: 6958 Comm: syz.1.367 Not tainted 5.15.185-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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_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_cut_from_item+0x1391/0x1ef0 fs/reiserfs/stree.c:1838 reiserfs_do_truncate+0xa90/0x13e0 fs/reiserfs/stree.c:1973 reiserfs_truncate_file+0x632/0xdc0 fs/reiserfs/inode.c:2318 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 handle_truncate fs/namei.c:3265 [inline] do_open fs/namei.c:3612 [inline] path_openat+0x28af/0x2f30 fs/namei.c:3742 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769 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 RIP: 0033:0x7f7febc29929 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:00007f7fe9a0b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f7febe51080 RCX: 00007f7febc29929 RDX: 000000000000275a RSI: 0000200000000040 RDI: ffffffffffffff9c RBP: 00007f7febcabb39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f7febe51080 R15: 00007ffda44144c8 The buggy address belongs to the page: page:ffffea0001716e00 refcount:2 mapcount:0 mapping:ffff888016d15af0 index:0x214 pfn:0x5c5b8 memcg:ffff88807787c000 aops:def_blk_aops ino:700001 flags: 0xfff00000002032(referenced|lru|active|private|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000002032 ffffea00017b48c8 ffffea000167d448 ffff888016d15af0 raw: 0000000000000214 ffff8880742f9658 00000002ffffffff ffff88807787c000 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 6958, ts 239410431381, free_ts 236016317864 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:5474 __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_paste_into_item+0x5c8/0x7e0 fs/reiserfs/stree.c:2130 reiserfs_get_block+0x1bde/0x4100 fs/reiserfs/inode.c:1077 __block_write_begin_int+0x54e/0x15a0 fs/buffer.c:2012 reiserfs_write_begin+0x34b/0x810 fs/reiserfs/inode.c:2790 generic_cont_expand_simple+0xe9/0x190 fs/buffer.c:2362 reiserfs_setattr+0x42f/0x1010 fs/reiserfs/inode.c:3319 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 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] shmem_undo_range+0x593/0x1840 mm/shmem.c:964 shmem_truncate_range mm/shmem.c:1063 [inline] shmem_evict_inode+0x20d/0xa00 mm/shmem.c:1145 evict+0x485/0x870 fs/inode.c:647 __dentry_kill+0x431/0x650 fs/dcache.c:586 dentry_kill+0xb8/0x290 fs/dcache.c:-1 dput+0xd8/0x1a0 fs/dcache.c:893 __fput+0x5ee/0x930 fs/file_table.c:319 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 Memory state around the buggy address: ffff88805c5b8f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88805c5b8f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88805c5b9000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88805c5b9080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88805c5b9100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================