[syzbot] [ntfs?] KMSAN: uninit-value in post_read_mst_fixup (2)

From: syzbot
Date: Tue Dec 26 2023 - 10:59:36 EST


Hello,

syzbot found the following issue on:

HEAD commit: 55cb5f43689d Merge tag 'trace-v6.7-rc6' of git://git.kerne..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=107247e1e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=4a65fa9f077ead01
dashboard link: https://syzkaller.appspot.com/bug?extid=82248056430fd49210e9
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ab88d88fa1d1/disk-55cb5f43.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/587fd1186192/vmlinux-55cb5f43.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c7bbb5741191/bzImage-55cb5f43.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+82248056430fd49210e9@xxxxxxxxxxxxxxxxxxxxxxxxx

syz-executor.1: attempt to access beyond end of device
loop1: rw=0, sector=2040, nr_sectors = 8 limit=190
ntfs: (device loop1): ntfs_end_buffer_async_read(): Buffer I/O error, logical block 0xff.
=====================================================
BUG: KMSAN: uninit-value in post_read_mst_fixup+0xab8/0xb70 fs/ntfs/mst.c:39
post_read_mst_fixup+0xab8/0xb70 fs/ntfs/mst.c:39
ntfs_end_buffer_async_read+0xbb8/0x1a70 fs/ntfs/aops.c:133
end_bio_bh_io_sync+0x130/0x1d0 fs/buffer.c:2775
bio_endio+0xb17/0xb70 block/bio.c:1603
submit_bio_noacct+0x230/0x2840 block/blk-core.c:816
submit_bio+0x171/0x1c0 block/blk-core.c:842
submit_bh_wbc+0x7de/0x850 fs/buffer.c:2821
submit_bh+0x26/0x30 fs/buffer.c:2826
ntfs_read_block fs/ntfs/aops.c:339 [inline]
ntfs_read_folio+0x364b/0x3930 fs/ntfs/aops.c:430
filemap_read_folio+0xce/0x370 mm/filemap.c:2323
do_read_cache_folio+0x3b4/0x11e0 mm/filemap.c:3691
do_read_cache_page mm/filemap.c:3757 [inline]
read_cache_page+0x63/0x1c0 mm/filemap.c:3766
read_mapping_page include/linux/pagemap.h:871 [inline]
ntfs_map_page fs/ntfs/aops.h:75 [inline]
check_mft_mirror fs/ntfs/super.c:1117 [inline]
load_system_files+0x985/0x97b0 fs/ntfs/super.c:1780
ntfs_fill_super+0x307e/0x45d0 fs/ntfs/super.c:2900
mount_bdev+0x3d7/0x560 fs/super.c:1650
ntfs_mount+0x4d/0x60 fs/ntfs/super.c:3057
legacy_get_tree+0x110/0x290 fs/fs_context.c:662
vfs_get_tree+0xa5/0x520 fs/super.c:1771
do_new_mount+0x68d/0x1550 fs/namespace.c:3337
path_mount+0x73d/0x1f20 fs/namespace.c:3664
do_mount fs/namespace.c:3677 [inline]
__do_sys_mount fs/namespace.c:3886 [inline]
__se_sys_mount+0x725/0x810 fs/namespace.c:3863
__x64_sys_mount+0xe4/0x140 fs/namespace.c:3863
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
do_read_cache_folio+0x163/0x11e0 mm/filemap.c:3655
do_read_cache_page mm/filemap.c:3757 [inline]
read_cache_page+0x63/0x1c0 mm/filemap.c:3766
read_mapping_page include/linux/pagemap.h:871 [inline]
ntfs_map_page fs/ntfs/aops.h:75 [inline]
check_mft_mirror fs/ntfs/super.c:1117 [inline]
load_system_files+0x985/0x97b0 fs/ntfs/super.c:1780
ntfs_fill_super+0x307e/0x45d0 fs/ntfs/super.c:2900
mount_bdev+0x3d7/0x560 fs/super.c:1650
ntfs_mount+0x4d/0x60 fs/ntfs/super.c:3057
legacy_get_tree+0x110/0x290 fs/fs_context.c:662
vfs_get_tree+0xa5/0x520 fs/super.c:1771
do_new_mount+0x68d/0x1550 fs/namespace.c:3337
path_mount+0x73d/0x1f20 fs/namespace.c:3664
do_mount fs/namespace.c:3677 [inline]
__do_sys_mount fs/namespace.c:3886 [inline]
__se_sys_mount+0x725/0x810 fs/namespace.c:3863
__x64_sys_mount+0xe4/0x140 fs/namespace.c:3863
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: 6133 Comm: syz-executor.1 Not tainted 6.7.0-rc6-syzkaller-00022-g55cb5f43689d #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 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