56 lines
1.3 KiB
C
56 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Ioctl to read verity metadata
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*
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* Copyright 2021 Google LLC
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*/
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#include "fsverity_private.h"
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#include <linux/uaccess.h>
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/**
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* fsverity_ioctl_read_metadata() - read verity metadata from a file
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* @filp: file to read the metadata from
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* @uarg: user pointer to fsverity_read_metadata_arg
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*
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* Return: length read on success, 0 on EOF, -errno on failure
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*/
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int fsverity_ioctl_read_metadata(struct file *filp, const void __user *uarg)
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{
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struct inode *inode = file_inode(filp);
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const struct fsverity_info *vi;
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struct fsverity_read_metadata_arg arg;
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int length;
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void __user *buf;
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vi = fsverity_get_info(inode);
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if (!vi)
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return -ENODATA; /* not a verity file */
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/*
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* Note that we don't have to explicitly check that the file is open for
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* reading, since verity files can only be opened for reading.
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*/
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if (copy_from_user(&arg, uarg, sizeof(arg)))
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return -EFAULT;
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if (arg.__reserved)
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return -EINVAL;
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/* offset + length must not overflow. */
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if (arg.offset + arg.length < arg.offset)
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return -EINVAL;
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/* Ensure that the return value will fit in INT_MAX. */
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length = min_t(u64, arg.length, INT_MAX);
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buf = u64_to_user_ptr(arg.buf_ptr);
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switch (arg.metadata_type) {
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default:
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return -EINVAL;
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}
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}
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EXPORT_SYMBOL_GPL(fsverity_ioctl_read_metadata);
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