Hello, syzbot found the following issue on: HEAD commit: 610a9b8f49fb Linux 6.7-rc8 git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=11a0f711e80000 kernel config: https://syzkaller.appspot.com/x/.config?x=e51fe20c3e51ba7f dashboard link: https://syzkaller.appspot.com/bug?extid=08d8956768c96a2c52cf compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=141f845ee80000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1413cf11e80000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/28ecdd56de1e/disk-610a9b8f.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/3c5afc17c174/vmlinux-610a9b8f.xz kernel image: https://storage.googleapis.com/syzbot-assets/96ff79b2992d/bzImage-610a9b8f.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/689e00cd89ff/mount_0.gz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+08d8956768c96a2c52cf@xxxxxxxxxxxxxxxxxxxxxxxxx ntfs3: loop0: Failed to initialize $Extend/$ObjId. ===================================================== BUG: KMSAN: uninit-value in longest_match_std+0x5d9/0xe00 fs/ntfs3/lznt.c:60 longest_match_std+0x5d9/0xe00 fs/ntfs3/lznt.c:60 compress_chunk fs/ntfs3/lznt.c:170 [inline] compress_lznt+0x41b/0xef0 fs/ntfs3/lznt.c:336 ni_write_frame+0xf89/0x1c80 fs/ntfs3/frecord.c:2839 ntfs_compress_write+0x2521/0x3b70 fs/ntfs3/file.c:995 ntfs_file_write_iter+0x89b/0xd30 fs/ntfs3/file.c:1081 call_write_iter include/linux/fs.h:2020 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x8ef/0x1490 fs/read_write.c:584 ksys_write+0x20f/0x4c0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x93/0xd0 fs/read_write.c:646 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b Uninit was created at: __alloc_pages+0x9a4/0xe00 mm/page_alloc.c:4591 alloc_pages_mpol+0x62b/0x9d0 mm/mempolicy.c:2133 alloc_pages mm/mempolicy.c:2204 [inline] folio_alloc+0x1da/0x380 mm/mempolicy.c:2211 filemap_alloc_folio+0xa5/0x430 mm/filemap.c:974 __filemap_get_folio+0xa5a/0x1760 mm/filemap.c:1918 pagecache_get_page+0x4a/0x1a0 mm/folio-compat.c:99 find_or_create_page include/linux/pagemap.h:740 [inline] ntfs_get_frame_pages+0xdc/0x9f0 fs/ntfs3/file.c:794 ntfs_compress_write+0x1b0b/0x3b70 fs/ntfs3/file.c:944 ntfs_file_write_iter+0x89b/0xd30 fs/ntfs3/file.c:1081 call_write_iter include/linux/fs.h:2020 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x8ef/0x1490 fs/read_write.c:584 ksys_write+0x20f/0x4c0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x93/0xd0 fs/read_write.c:646 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b CPU: 0 PID: 4999 Comm: syz-executor227 Not tainted 6.7.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 ===================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup