lkml.org 
[lkml]   [2020]   [Oct]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v5 09/16] firmware_loader: Use security_post_load_data()
Date
Now that security_post_load_data() is wired up, use it instead
of the NULL file argument style of security_post_read_file(),
and update the security_kernel_load_data() call to indicate that a
security_kernel_post_load_data() call is expected.

Wire up the IMA check to match earlier logic. Perhaps a generalized
change to ima_post_load_data() might look something like this:

return process_buffer_measurement(buf, size,
kernel_load_data_id_str(load_id),
read_idmap[load_id] ?: FILE_CHECK,
0, NULL);

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
---
drivers/base/firmware_loader/fallback.c | 8 ++++----
.../base/firmware_loader/fallback_platform.c | 8 +++++++-
security/integrity/ima/ima_main.c | 20 +++++++++----------
3 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index bff4717cc6b5..251d92fc8bae 100644
--- a/drivers/base/firmware_loader/fallback.c
+++ b/drivers/base/firmware_loader/fallback.c
@@ -272,9 +272,9 @@ static ssize_t firmware_loading_store(struct device *dev,
dev_err(dev, "%s: map pages failed\n",
__func__);
else
- rc = security_kernel_post_read_file(NULL,
- fw_priv->data, fw_priv->size,
- READING_FIRMWARE);
+ rc = security_kernel_post_load_data(fw_priv->data,
+ fw_priv->size,
+ LOADING_FIRMWARE, "blob");

/*
* Same logic as fw_load_abort, only the DONE bit
@@ -613,7 +613,7 @@ static bool fw_run_sysfs_fallback(u32 opt_flags)
return false;

/* Also permit LSMs and IMA to fail firmware sysfs fallback */
- ret = security_kernel_load_data(LOADING_FIRMWARE, false);
+ ret = security_kernel_load_data(LOADING_FIRMWARE, true);
if (ret < 0)
return false;

diff --git a/drivers/base/firmware_loader/fallback_platform.c b/drivers/base/firmware_loader/fallback_platform.c
index a12c79d47efc..8bdf88043079 100644
--- a/drivers/base/firmware_loader/fallback_platform.c
+++ b/drivers/base/firmware_loader/fallback_platform.c
@@ -17,7 +17,7 @@ int firmware_fallback_platform(struct fw_priv *fw_priv, u32 opt_flags)
if (!(opt_flags & FW_OPT_FALLBACK_PLATFORM))
return -ENOENT;

- rc = security_kernel_load_data(LOADING_FIRMWARE, false);
+ rc = security_kernel_load_data(LOADING_FIRMWARE, true);
if (rc)
return rc;

@@ -27,6 +27,12 @@ int firmware_fallback_platform(struct fw_priv *fw_priv, u32 opt_flags)

if (fw_priv->data && size > fw_priv->allocated_size)
return -ENOMEM;
+
+ rc = security_kernel_post_load_data((u8 *)data, size, LOADING_FIRMWARE,
+ "platform");
+ if (rc)
+ return rc;
+
if (!fw_priv->data)
fw_priv->data = vmalloc(size);
if (!fw_priv->data)
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 9dd9c5f4d736..6f2b8352573a 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -648,15 +648,6 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
enum ima_hooks func;
u32 secid;

- if (!file && read_id == READING_FIRMWARE) {
- if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
- (ima_appraise & IMA_APPRAISE_ENFORCE)) {
- pr_err("Prevent firmware loading_store.\n");
- return -EACCES; /* INTEGRITY_UNKNOWN */
- }
- return 0;
- }
-
/* permit signed certs */
if (!file && read_id == READING_X509_CERTIFICATE)
return 0;
@@ -706,7 +697,7 @@ int ima_load_data(enum kernel_load_data_id id, bool contents)
}
break;
case LOADING_FIRMWARE:
- if (ima_enforce && (ima_appraise & IMA_APPRAISE_FIRMWARE)) {
+ if (ima_enforce && (ima_appraise & IMA_APPRAISE_FIRMWARE) && !contents) {
pr_err("Prevent firmware sysfs fallback loading.\n");
return -EACCES; /* INTEGRITY_UNKNOWN */
}
@@ -742,6 +733,15 @@ int ima_post_load_data(char *buf, loff_t size,
enum kernel_load_data_id load_id,
char *description)
{
+ if (load_id == LOADING_FIRMWARE) {
+ if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
+ (ima_appraise & IMA_APPRAISE_ENFORCE)) {
+ pr_err("Prevent firmware loading_store.\n");
+ return -EACCES; /* INTEGRITY_UNKNOWN */
+ }
+ return 0;
+ }
+
return 0;
}

--
2.25.1
\
 
 \ /
  Last update: 2020-10-02 19:39    [W:0.226 / U:2.932 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site