To prevent inodes with invalid file types from tripping through the vfs and causing malfunctions or assertion failures, add a missing sanity check when reading an inode from a block device. If the file type is not valid, treat it as a filesystem error. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx> Reported-by: syzbot+895c23f6917da440ed0d@xxxxxxxxxxxxxxxxxxxxxxxxx Link: https://syzkaller.appspot.com/bug?extid=895c23f6917da440ed0d Cc: stable@xxxxxxxxxxxxxxx Fixes: 05fe58fdc10d ("nilfs2: inode operations") --- Hi Andrew, please apply this as a bug fix. This fixes a missing check in nilfs2 that could allow invalid file types to be imported from corrupted filesystem images, as reported by syzbot following a recently added VFS assertion. Thanks, Ryusuke Konishi fs/nilfs2/inode.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c index 6613b8fcceb0..5cf7328d5360 100644 --- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -472,11 +472,18 @@ static int __nilfs_read_inode(struct super_block *sb, inode->i_op = &nilfs_symlink_inode_operations; inode_nohighmem(inode); inode->i_mapping->a_ops = &nilfs_aops; - } else { + } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || + S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { inode->i_op = &nilfs_special_inode_operations; init_special_inode( inode, inode->i_mode, huge_decode_dev(le64_to_cpu(raw_inode->i_device_code))); + } else { + nilfs_error(sb, + "invalid file type bits in mode 0%o for inode %lu", + inode->i_mode, ino); + err = -EIO; + goto failed_unmap; } nilfs_ifile_unmap_inode(raw_inode); brelse(bh); -- 2.43.0
