REISERFS (device loop0): using ordered data mode reiserfs: using flush barriers REISERFS (device loop0): journal params: device loop0, size 512, journal first block 18, max trans len 256, max batch 225, max commit age 30, max trans age 30 REISERFS (device loop0): checking transaction log (loop0) REISERFS (device loop0): Using r5 hash to sort names ================================================================== BUG: KASAN: use-after-free in set_de_name_and_namelen+0x664/0x6a0 fs/reiserfs/namei.c:81 Read of size 1 at addr ffff88805803e3cb by task syz.0.1585/17487 CPU: 1 PID: 17487 Comm: syz.0.1585 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xac/0x220 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 set_de_name_and_namelen+0x664/0x6a0 fs/reiserfs/namei.c:81 linear_search_in_dir_item fs/reiserfs/namei.c:262 [inline] reiserfs_find_entry+0x5e0/0x1310 fs/reiserfs/namei.c:331 reiserfs_lookup+0x1b9/0x520 fs/reiserfs/namei.c:368 __lookup_slow+0x281/0x3b0 fs/namei.c:1702 lookup_one_len+0x192/0x2c0 fs/namei.c:2752 reiserfs_lookup_privroot+0x89/0x180 fs/reiserfs/xattr.c:977 reiserfs_fill_super+0x16f3/0x2340 fs/reiserfs/super.c:2192 mount_bdev+0x22b/0x2d0 fs/super.c:1643 legacy_get_tree+0xea/0x180 fs/fs_context.c:662 vfs_get_tree+0x8c/0x280 fs/super.c:1764 do_new_mount+0x24b/0xa40 fs/namespace.c:3386 do_mount fs/namespace.c:3726 [inline] __do_sys_mount fs/namespace.c:3935 [inline] __se_sys_mount+0x2da/0x3c0 fs/namespace.c:3912 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8cac590eea Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f8cad476e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f8cad476ef0 RCX: 00007f8cac590eea RDX: 0000200000000000 RSI: 0000200000000140 RDI: 00007f8cad476eb0 RBP: 0000200000000000 R08: 00007f8cad476ef0 R09: 000000000120c083 R10: 000000000120c083 R11: 0000000000000246 R12: 0000200000000140 R13: 00007f8cad476eb0 R14: 000000000000111e R15: 0000200000000480 The buggy address belongs to the physical page: page:ffffea0001600f80 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x5803e flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000000 ffffea0001600fc8 ffff8880b8f41f20 0000000000000000 raw: 0000000000000001 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 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 17384, tgid 17382 (syz.7.1560), ts 817616168311, free_ts 818419076698 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457 __folio_alloc+0x10/0x20 mm/page_alloc.c:4489 vma_alloc_folio+0x47a/0x8f0 mm/mempolicy.c:2242 shmem_alloc_folio+0x179/0x230 mm/shmem.c:1679 shmem_alloc_and_acct_folio+0x189/0x630 mm/shmem.c:1704 shmem_get_folio_gfp+0xcde/0x2ac0 mm/shmem.c:2041 shmem_fault+0x1b6/0x7f0 mm/shmem.c:2248 __do_fault+0x13b/0x4e0 mm/memory.c:4244 do_read_fault mm/memory.c:4638 [inline] do_fault mm/memory.c:4775 [inline] do_pte_missing mm/memory.c:3689 [inline] handle_pte_fault mm/memory.c:5047 [inline] __handle_mm_fault mm/memory.c:5188 [inline] handle_mm_fault+0x3886/0x4920 mm/memory.c:5353 faultin_page mm/gup.c:868 [inline] __get_user_pages+0x5ea/0x1470 mm/gup.c:1167 populate_vma_page_range+0x2b6/0x370 mm/gup.c:1593 __mm_populate+0x24c/0x380 mm/gup.c:1696 mm_populate include/linux/mm.h:3383 [inline] vm_mmap_pgoff+0x2e7/0x400 mm/util.c:561 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1154 [inline] free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336 free_unref_page_list+0xbe/0x860 mm/page_alloc.c:2475 release_pages+0x1fa0/0x2220 mm/swap.c:1022 __folio_batch_release+0x71/0xe0 mm/swap.c:1042 folio_batch_release include/linux/pagevec.h:83 [inline] shmem_undo_range+0x5d0/0x1a40 mm/shmem.c:1026 shmem_truncate_range mm/shmem.c:1135 [inline] shmem_evict_inode+0x273/0xa70 mm/shmem.c:1264 evict+0x486/0x870 fs/inode.c:705 __dentry_kill+0x431/0x650 fs/dcache.c:611 dentry_kill+0xb8/0x290 fs/dcache.c:-1 dput+0xfe/0x1e0 fs/dcache.c:918 __fput+0x5e5/0x970 fs/file_table.c:392 task_work_run+0x1ce/0x250 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x90b/0x23c0 kernel/exit.c:883 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310 Memory state around the buggy address: ffff88805803e280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88805803e300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88805803e380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88805803e400: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88805803e480: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================