Re: [PATCH 06/13] fs/kernel_read_file: Remove redundant size argument

From: Scott Branden
Date: Tue Jul 21 2020 - 17:43:27 EST


Hi Kees,

On 2020-07-17 10:43 a.m., Kees Cook wrote:
In preparation for refactoring kernel_read_file*(), remove the redundant
"size" argument which is not needed: it can be included in the return
code, with callers adjusted. (VFS reads already cannot be larger than
INT_MAX.)

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
drivers/base/firmware_loader/main.c | 8 ++++----
fs/kernel_read_file.c | 20 +++++++++-----------
include/linux/kernel_read_file.h | 8 ++++----
kernel/kexec_file.c | 13 ++++++-------
kernel/module.c | 7 +++----
security/integrity/digsig.c | 5 +++--
security/integrity/ima/ima_fs.c | 5 +++--
7 files changed, 32 insertions(+), 34 deletions(-)

diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index d4a413ea48ce..ea419c7d3d34 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -462,7 +462,7 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
size_t in_size,
const void *in_buffer))
{
- loff_t size;
+ size_t size;
int i, len;
int rc = -ENOENT;
char *path;
@@ -494,10 +494,9 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
fw_priv->size = 0;
/* load firmware files from the mount namespace of init */
- rc = kernel_read_file_from_path_initns(path, &buffer,
- &size, msize,
+ rc = kernel_read_file_from_path_initns(path, &buffer, msize,
READING_FIRMWARE);
- if (rc) {
+ if (rc < 0) {
if (rc != -ENOENT)
dev_warn(device, "loading %s failed with error %d\n",
path, rc);
@@ -506,6 +505,7 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
path);
continue;
}
+ size = rc;
Change fails to return 0. Need rc = 0; here.
dev_dbg(device, "Loading firmware from %s\n", path);
if (decompress) {
dev_dbg(device, "f/w decompressing %s\n",