================================================================== BUG: KASAN: use-after-free in reiserfs_release_objectid+0x521/0x780 fs/reiserfs/objectid.c:165 Read of size 8188 at addr ffff888066f75050 by task syz.7.259/5648 CPU: 0 PID: 5648 Comm: syz.7.259 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 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 memmove+0x25/0x60 mm/kasan/shadow.c:54 reiserfs_release_objectid+0x521/0x780 fs/reiserfs/objectid.c:165 remove_save_link+0x2b6/0x3c0 fs/reiserfs/super.c:542 reiserfs_evict_inode+0x393/0x490 fs/reiserfs/inode.c:91 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 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x61e/0x20a0 kernel/exit.c:883 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 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 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7febd55104e5 Code: Unable to access opcode bytes at RIP 0x7febd55104bb. RSP: 002b:00007fff6e892ca0 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: 0000000000000000 RBX: 00007febd5724fa0 RCX: 00007febd55104e5 RDX: 00007fff6e892ce0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007febd5726da0 R08: 0000000000000000 R09: 00093be200bf78ce R10: 0000000000000000 R11: 0000000000000293 R12: 000000000002b407 R13: 00007febd5725090 R14: ffffffffffffffff R15: 00007fff6e892e20 The buggy address belongs to the page: page:ffffea00019bdd40 refcount:2 mapcount:0 mapping:ffff8881408d2bf0 index:0x10 pfn:0x66f75 memcg:ffff88807af9c000 aops:def_blk_aops ino:700007 flags: 0xfff00000022036(referenced|uptodate|lru|active|private|mappedtodisk|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000022036 ffffea0001cc7d48 ffffea00016f4248 ffff8881408d2bf0 raw: 0000000000000010 ffff888052839488 00000002ffffffff ffff88807af9c000 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 5649, ts 171893995298, free_ts 171840307247 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:5487 __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 __bread_gfp+0x28/0x380 fs/buffer.c:1381 sb_bread include/linux/buffer_head.h:337 [inline] read_super_block+0x91/0x7a0 fs/reiserfs/super.c:1606 reiserfs_fill_super+0x787/0x23e0 fs/reiserfs/super.c:1968 mount_bdev+0x287/0x3c0 fs/super.c:1400 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/0xa40 fs/namespace.c:3025 do_mount fs/namespace.c:3368 [inline] __do_sys_mount fs/namespace.c:3576 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3553 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 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 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:240 [inline] tlb_flush_mmu mm/mmu_gather.c:247 [inline] tlb_finish_mmu+0x164/0x2e0 mm/mmu_gather.c:338 unmap_region+0x315/0x360 mm/mmap.c:2669 __do_munmap+0x9d3/0xdc0 mm/mmap.c:2899 __vm_munmap+0x137/0x230 mm/mmap.c:2952 __do_sys_munmap mm/mmap.c:2978 [inline] __se_sys_munmap mm/mmap.c:2974 [inline] __x64_sys_munmap+0x67/0x70 mm/mmap.c:2974 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: ffff888066f75f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888066f75f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888066f76000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888066f76080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888066f76100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================