From 885352881f11f1f3113d8eb877786bcb6d720544 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 2 Oct 2020 10:38:19 -0700 Subject: fs/kernel_read_file: Add file_size output argument In preparation for adding partial read support, add an optional output argument to kernel_read_file*() that reports the file size so callers can reason more easily about their reading progress. Signed-off-by: Kees Cook Reviewed-by: Mimi Zohar Reviewed-by: Luis Chamberlain Reviewed-by: James Morris Acked-by: Scott Branden Link: https://lore.kernel.org/r/20201002173828.2099543-8-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman --- drivers/base/firmware_loader/main.c | 1 + fs/kernel_read_file.c | 19 +++++++++++++------ include/linux/kernel_read_file.h | 4 ++++ kernel/kexec_file.c | 4 ++-- kernel/module.c | 2 +- security/integrity/digsig.c | 2 +- security/integrity/ima/ima_fs.c | 2 +- 7 files changed, 23 insertions(+), 11 deletions(-) diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c index 6df1bdcfeb9d..d9a180148c4b 100644 --- a/drivers/base/firmware_loader/main.c +++ b/drivers/base/firmware_loader/main.c @@ -500,6 +500,7 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv, /* load firmware files from the mount namespace of init */ rc = kernel_read_file_from_path_initns(path, &buffer, msize, + NULL, READING_FIRMWARE); if (rc < 0) { if (rc != -ENOENT) diff --git a/fs/kernel_read_file.c b/fs/kernel_read_file.c index e21a76001fff..2e29c38eb4df 100644 --- a/fs/kernel_read_file.c +++ b/fs/kernel_read_file.c @@ -14,6 +14,8 @@ * @buf_size will be ignored) * @buf_size size of buf, if already allocated. If @buf not * allocated, this is the largest size to allocate. + * @file_size if non-NULL, the full size of @file will be + * written here. * @id the kernel_read_file_id identifying the type of * file contents being read (for LSMs to examine) * @@ -22,7 +24,8 @@ * */ int kernel_read_file(struct file *file, void **buf, - size_t buf_size, enum kernel_read_file_id id) + size_t buf_size, size_t *file_size, + enum kernel_read_file_id id) { loff_t i_size, pos; ssize_t bytes = 0; @@ -49,6 +52,8 @@ int kernel_read_file(struct file *file, void **buf, ret = -EFBIG; goto out; } + if (file_size) + *file_size = i_size; if (!*buf) *buf = allocated = vmalloc(i_size); @@ -91,7 +96,8 @@ out: EXPORT_SYMBOL_GPL(kernel_read_file); int kernel_read_file_from_path(const char *path, void **buf, - size_t buf_size, enum kernel_read_file_id id) + size_t buf_size, size_t *file_size, + enum kernel_read_file_id id) { struct file *file; int ret; @@ -103,14 +109,14 @@ int kernel_read_file_from_path(const char *path, void **buf, if (IS_ERR(file)) return PTR_ERR(file); - ret = kernel_read_file(file, buf, buf_size, id); + ret = kernel_read_file(file, buf, buf_size, file_size, id); fput(file); return ret; } EXPORT_SYMBOL_GPL(kernel_read_file_from_path); int kernel_read_file_from_path_initns(const char *path, void **buf, - size_t buf_size, + size_t buf_size, size_t *file_size, enum kernel_read_file_id id) { struct file *file; @@ -129,13 +135,14 @@ int kernel_read_file_from_path_initns(const char *path, void **buf, if (IS_ERR(file)) return PTR_ERR(file); - ret = kernel_read_file(file, buf, buf_size, id); + ret = kernel_read_file(file, buf, buf_size, file_size, id); fput(file); return ret; } EXPORT_SYMBOL_GPL(kernel_read_file_from_path_initns); int kernel_read_file_from_fd(int fd, void **buf, size_t buf_size, + size_t *file_size, enum kernel_read_file_id id) { struct fd f = fdget(fd); @@ -144,7 +151,7 @@ int kernel_read_file_from_fd(int fd, void **buf, size_t buf_size, if (!f.file) goto out; - ret = kernel_read_file(f.file, buf, buf_size, id); + ret = kernel_read_file(f.file, buf, buf_size, file_size, id); out: fdput(f); return ret; diff --git a/include/linux/kernel_read_file.h b/include/linux/kernel_read_file.h index 910039e7593e..023293eaf948 100644 --- a/include/linux/kernel_read_file.h +++ b/include/linux/kernel_read_file.h @@ -37,15 +37,19 @@ static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id) int kernel_read_file(struct file *file, void **buf, size_t buf_size, + size_t *file_size, enum kernel_read_file_id id); int kernel_read_file_from_path(const char *path, void **buf, size_t buf_size, + size_t *file_size, enum kernel_read_file_id id); int kernel_read_file_from_path_initns(const char *path, void **buf, size_t buf_size, + size_t *file_size, enum kernel_read_file_id id); int kernel_read_file_from_fd(int fd, void **buf, size_t buf_size, + size_t *file_size, enum kernel_read_file_id id); #endif /* _LINUX_KERNEL_READ_FILE_H */ diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index b20cfde8a01d..ee51c1028658 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -222,7 +222,7 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd, void *ldata; ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf, - INT_MAX, READING_KEXEC_IMAGE); + INT_MAX, NULL, READING_KEXEC_IMAGE); if (ret < 0) return ret; image->kernel_buf_len = ret; @@ -242,7 +242,7 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd, /* It is possible that there no initramfs is being loaded */ if (!(flags & KEXEC_FILE_NO_INITRAMFS)) { ret = kernel_read_file_from_fd(initrd_fd, &image->initrd_buf, - INT_MAX, + INT_MAX, NULL, READING_KEXEC_INITRAMFS); if (ret < 0) goto out; diff --git a/kernel/module.c b/kernel/module.c index 9faa6322f17b..0f11eaed047e 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -4048,7 +4048,7 @@ SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags) |MODULE_INIT_IGNORE_VERMAGIC)) return -EINVAL; - err = kernel_read_file_from_fd(fd, &hdr, INT_MAX, + err = kernel_read_file_from_fd(fd, &hdr, INT_MAX, NULL, READING_MODULE); if (err < 0) return err; diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c index 04f779c4f5ed..8a523dfd7fd7 100644 --- a/security/integrity/digsig.c +++ b/security/integrity/digsig.c @@ -175,7 +175,7 @@ int __init integrity_load_x509(const unsigned int id, const char *path) int rc; key_perm_t perm; - rc = kernel_read_file_from_path(path, &data, INT_MAX, + rc = kernel_read_file_from_path(path, &data, INT_MAX, NULL, READING_X509_CERTIFICATE); if (rc < 0) { pr_err("Unable to open file: %s (%d)", path, rc); diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c index 692b83e82edf..5fc56ccb6678 100644 --- a/security/integrity/ima/ima_fs.c +++ b/security/integrity/ima/ima_fs.c @@ -284,7 +284,7 @@ static ssize_t ima_read_policy(char *path) datap = path; strsep(&datap, "\n"); - rc = kernel_read_file_from_path(path, &data, INT_MAX, READING_POLICY); + rc = kernel_read_file_from_path(path, &data, INT_MAX, NULL, READING_POLICY); if (rc < 0) { pr_err("Unable to open file: %s (%d)", path, rc); return rc; -- cgit v1.2.3