From 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 12:05:51 +0200 Subject: Adding upstream version 5.10.209. Signed-off-by: Daniel Baumann --- fs/verity/measure.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 fs/verity/measure.c (limited to 'fs/verity/measure.c') diff --git a/fs/verity/measure.c b/fs/verity/measure.c new file mode 100644 index 000000000..df409a568 --- /dev/null +++ b/fs/verity/measure.c @@ -0,0 +1,59 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * fs/verity/measure.c: ioctl to get a verity file's measurement + * + * Copyright 2019 Google LLC + */ + +#include "fsverity_private.h" + +#include + +/** + * fsverity_ioctl_measure() - get a verity file's measurement + * @filp: file to get measurement of + * @_uarg: user pointer to fsverity_digest + * + * Retrieve the file measurement that the kernel is enforcing for reads from a + * verity file. See the "FS_IOC_MEASURE_VERITY" section of + * Documentation/filesystems/fsverity.rst for the documentation. + * + * Return: 0 on success, -errno on failure + */ +int fsverity_ioctl_measure(struct file *filp, void __user *_uarg) +{ + const struct inode *inode = file_inode(filp); + struct fsverity_digest __user *uarg = _uarg; + const struct fsverity_info *vi; + const struct fsverity_hash_alg *hash_alg; + struct fsverity_digest arg; + + vi = fsverity_get_info(inode); + if (!vi) + return -ENODATA; /* not a verity file */ + hash_alg = vi->tree_params.hash_alg; + + /* + * The user specifies the digest_size their buffer has space for; we can + * return the digest if it fits in the available space. We write back + * the actual size, which may be shorter than the user-specified size. + */ + + if (get_user(arg.digest_size, &uarg->digest_size)) + return -EFAULT; + if (arg.digest_size < hash_alg->digest_size) + return -EOVERFLOW; + + memset(&arg, 0, sizeof(arg)); + arg.digest_algorithm = hash_alg - fsverity_hash_algs; + arg.digest_size = hash_alg->digest_size; + + if (copy_to_user(uarg, &arg, sizeof(arg))) + return -EFAULT; + + if (copy_to_user(uarg->digest, vi->measurement, hash_alg->digest_size)) + return -EFAULT; + + return 0; +} +EXPORT_SYMBOL_GPL(fsverity_ioctl_measure); -- cgit v1.2.3