To differentiate between the kernel_read_file() callers, this patch
defines a new enumeration named kernel_read_file_id and includes the
caller identifier as an argument.
Subsequent patches define READING_KEXEC_IMAGE, READING_KEXEC_INITRAMFS,
READING_FIRMWARE, READING_MODULE, and READING_POLICY.
Changelog v3:
- Replace the IMA specific enumeration with a generic one.
Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx>
Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>
Acked-by: Luis R. Rodriguez <mcgrof@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
fs/exec.c | 4 ++--
include/linux/fs.h | 7 ++++++-
include/linux/lsm_hooks.h | 4 +++-
include/linux/security.h | 7 +++++--
security/security.c | 5 +++--
5 files changed, 19 insertions(+), 8 deletions(-)
diff --git a/fs/exec.c b/fs/exec.c
index 6b6668b..1138dc5 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -833,7 +833,7 @@ int kernel_read(struct file *file, loff_t offset,
EXPORT_SYMBOL(kernel_read);
int kernel_read_file(struct file *file, void **buf, loff_t *size,
- loff_t max_size)
+ loff_t max_size, enum kernel_read_file_id id)
{
loff_t i_size, pos;
ssize_t bytes = 0;
@@ -871,7 +871,7 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size,
goto out;
}
- ret = security_kernel_post_read_file(file, *buf, i_size);
+ ret = security_kernel_post_read_file(file, *buf, i_size, id);
if (!ret)
*size = pos;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 9a83d82..aa84bcb 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2576,8 +2576,13 @@ static inline void i_readcount_inc(struct inode *inode)
#endif
extern int do_pipe_flags(int *, int);
+enum kernel_read_file_id {
+ READING_MAX_ID
+};
+
extern int kernel_read(struct file *, loff_t, char *, unsigned long);
-extern int kernel_read_file(struct file *, void **, loff_t *, loff_t);
+extern int kernel_read_file(struct file *, void **, loff_t *, loff_t,
+ enum kernel_read_file_id);
extern ssize_t kernel_write(struct file *, const char *, size_t, loff_t);
extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *);
extern struct file * open_exec(const char *);
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index f82631c..2337f33 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -567,6 +567,7 @@
* by the kernel.
* @buf pointer to buffer containing the file contents.
* @size length of the file contents.
+ * @id kernel read file identifier
* Return 0 if permission is granted.
* @task_fix_setuid:
* Update the module's state after setting one or more of the user
@@ -1464,7 +1465,8 @@ union security_list_options {
int (*kernel_fw_from_file)(struct file *file, char *buf, size_t size);
int (*kernel_module_request)(char *kmod_name);
int (*kernel_module_from_file)(struct file *file);
- int (*kernel_post_read_file)(struct file *file, char *buf, loff_t size);
+ int (*kernel_post_read_file)(struct file *file, char *buf, loff_t size,
+ enum kernel_read_file_id id);
int (*task_fix_setuid)(struct cred *new, const struct cred *old,
int flags);
int (*task_setpgid)(struct task_struct *p, pid_t pgid);
diff --git a/include/linux/security.h b/include/linux/security.h
index f30f564..b68ce94 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -28,6 +28,7 @@
#include <linux/err.h>
#include <linux/string.h>
#include <linux/mm.h>
+#include <linux/fs.h>
struct linux_binprm;
struct cred;
@@ -301,7 +302,8 @@ int security_kernel_create_files_as(struct cred *new, struct inode *inode);
int security_kernel_fw_from_file(struct file *file, char *buf, size_t size);
int security_kernel_module_request(char *kmod_name);
int security_kernel_module_from_file(struct file *file);
-int security_kernel_post_read_file(struct file *file, char *buf, loff_t size);
+int security_kernel_post_read_file(struct file *file, char *buf, loff_t size,
+ enum kernel_read_file_id id);
int security_task_fix_setuid(struct cred *new, const struct cred *old,
int flags);
int security_task_setpgid(struct task_struct *p, pid_t pgid);
@@ -868,7 +870,8 @@ static inline int security_kernel_module_from_file(struct file *file)
}
static inline int security_kernel_post_read_file(struct file *file,
- char *buf, loff_t size)
+ char *buf, loff_t size,
+ enum kernel_read_file_id id)
{
return 0;
}
diff --git a/security/security.c b/security/security.c
index ae50730..796a261 100644
--- a/security/security.c
+++ b/security/security.c
@@ -910,9 +910,10 @@ int security_kernel_module_from_file(struct file *file)
return ima_module_check(file);
}
-int security_kernel_post_read_file(struct file *file, char *buf, loff_t size)
+int security_kernel_post_read_file(struct file *file, char *buf, loff_t size,
+ enum kernel_read_file_id id)
{
- return call_int_hook(kernel_post_read_file, 0, file, buf, size);
+ return call_int_hook(kernel_post_read_file, 0, file, buf, size, id);
}
int security_task_fix_setuid(struct cred *new, const struct cred *old,
--
2.1.0
--
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