[PATCH v15 03/11] proc: Use lsmids instead of lsm names for attrs
Casey Schaufler
casey at schaufler-ca.com
Tue Sep 12 20:56:48 UTC 2023
Use the LSM ID number instead of the LSM name to identify which
security module's attibute data should be shown in /proc/self/attr.
The security_[gs]etprocattr() functions have been changed to expect
the LSM ID. The change from a string comparison to an integer comparison
in these functions will provide a minor performance improvement.
Signed-off-by: Casey Schaufler <casey at schaufler-ca.com>
Reviewed-by: Kees Cook <keescook at chromium.org>
Reviewed-by: Serge Hallyn <serge at hallyn.com>
Reviewed-by: Mickael Salaun <mic at digikod.net>
Reviewed-by: John Johansen <john.johansen at canonical.com>
Cc: linux-fsdevel at vger.kernel.org
---
fs/proc/base.c | 29 +++++++++++++++--------------
fs/proc/internal.h | 2 +-
include/linux/security.h | 11 +++++------
security/security.c | 15 +++++++--------
4 files changed, 28 insertions(+), 29 deletions(-)
diff --git a/fs/proc/base.c b/fs/proc/base.c
index ffd54617c354..97ce30528f75 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -97,6 +97,7 @@
#include <linux/resctrl.h>
#include <linux/cn_proc.h>
#include <linux/ksm.h>
+#include <uapi/linux/lsm.h>
#include <trace/events/oom.h>
#include "internal.h"
#include "fd.h"
@@ -146,10 +147,10 @@ struct pid_entry {
NOD(NAME, (S_IFREG|(MODE)), \
NULL, &proc_single_file_operations, \
{ .proc_show = show } )
-#define ATTR(LSM, NAME, MODE) \
+#define ATTR(LSMID, NAME, MODE) \
NOD(NAME, (S_IFREG|(MODE)), \
NULL, &proc_pid_attr_operations, \
- { .lsm = LSM })
+ { .lsmid = LSMID })
/*
* Count the number of hardlinks for the pid_entry table, excluding the .
@@ -2730,7 +2731,7 @@ static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
if (!task)
return -ESRCH;
- length = security_getprocattr(task, PROC_I(inode)->op.lsm,
+ length = security_getprocattr(task, PROC_I(inode)->op.lsmid,
file->f_path.dentry->d_name.name,
&p);
put_task_struct(task);
@@ -2788,7 +2789,7 @@ static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
if (rv < 0)
goto out_free;
- rv = security_setprocattr(PROC_I(inode)->op.lsm,
+ rv = security_setprocattr(PROC_I(inode)->op.lsmid,
file->f_path.dentry->d_name.name, page,
count);
mutex_unlock(¤t->signal->cred_guard_mutex);
@@ -2837,27 +2838,27 @@ static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
#ifdef CONFIG_SECURITY_SMACK
static const struct pid_entry smack_attr_dir_stuff[] = {
- ATTR("smack", "current", 0666),
+ ATTR(LSM_ID_SMACK, "current", 0666),
};
LSM_DIR_OPS(smack);
#endif
#ifdef CONFIG_SECURITY_APPARMOR
static const struct pid_entry apparmor_attr_dir_stuff[] = {
- ATTR("apparmor", "current", 0666),
- ATTR("apparmor", "prev", 0444),
- ATTR("apparmor", "exec", 0666),
+ ATTR(LSM_ID_APPARMOR, "current", 0666),
+ ATTR(LSM_ID_APPARMOR, "prev", 0444),
+ ATTR(LSM_ID_APPARMOR, "exec", 0666),
};
LSM_DIR_OPS(apparmor);
#endif
static const struct pid_entry attr_dir_stuff[] = {
- ATTR(NULL, "current", 0666),
- ATTR(NULL, "prev", 0444),
- ATTR(NULL, "exec", 0666),
- ATTR(NULL, "fscreate", 0666),
- ATTR(NULL, "keycreate", 0666),
- ATTR(NULL, "sockcreate", 0666),
+ ATTR(LSM_ID_UNDEF, "current", 0666),
+ ATTR(LSM_ID_UNDEF, "prev", 0444),
+ ATTR(LSM_ID_UNDEF, "exec", 0666),
+ ATTR(LSM_ID_UNDEF, "fscreate", 0666),
+ ATTR(LSM_ID_UNDEF, "keycreate", 0666),
+ ATTR(LSM_ID_UNDEF, "sockcreate", 0666),
#ifdef CONFIG_SECURITY_SMACK
DIR("smack", 0555,
proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index 9dda7e54b2d0..a889d9ef9584 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -92,7 +92,7 @@ union proc_op {
int (*proc_show)(struct seq_file *m,
struct pid_namespace *ns, struct pid *pid,
struct task_struct *task);
- const char *lsm;
+ int lsmid;
};
struct proc_inode {
diff --git a/include/linux/security.h b/include/linux/security.h
index c1a6af37a538..3f79bc191a7c 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -472,10 +472,9 @@ int security_sem_semctl(struct kern_ipc_perm *sma, int cmd);
int security_sem_semop(struct kern_ipc_perm *sma, struct sembuf *sops,
unsigned nsops, int alter);
void security_d_instantiate(struct dentry *dentry, struct inode *inode);
-int security_getprocattr(struct task_struct *p, const char *lsm, const char *name,
+int security_getprocattr(struct task_struct *p, int lsmid, const char *name,
char **value);
-int security_setprocattr(const char *lsm, const char *name, void *value,
- size_t size);
+int security_setprocattr(int lsmid, const char *name, void *value, size_t size);
int security_netlink_send(struct sock *sk, struct sk_buff *skb);
int security_ismaclabel(const char *name);
int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
@@ -1339,14 +1338,14 @@ static inline void security_d_instantiate(struct dentry *dentry,
struct inode *inode)
{ }
-static inline int security_getprocattr(struct task_struct *p, const char *lsm,
+static inline int security_getprocattr(struct task_struct *p, int lsmid,
const char *name, char **value)
{
return -EINVAL;
}
-static inline int security_setprocattr(const char *lsm, char *name,
- void *value, size_t size)
+static inline int security_setprocattr(int lsmid, char *name, void *value,
+ size_t size)
{
return -EINVAL;
}
diff --git a/security/security.c b/security/security.c
index f71715a6f5dd..a3489c04b783 100644
--- a/security/security.c
+++ b/security/security.c
@@ -3840,7 +3840,7 @@ EXPORT_SYMBOL(security_d_instantiate);
/**
* security_getprocattr() - Read an attribute for a task
* @p: the task
- * @lsm: LSM name
+ * @lsmid: LSM identification
* @name: attribute name
* @value: attribute value
*
@@ -3848,13 +3848,13 @@ EXPORT_SYMBOL(security_d_instantiate);
*
* Return: Returns the length of @value on success, a negative value otherwise.
*/
-int security_getprocattr(struct task_struct *p, const char *lsm,
- const char *name, char **value)
+int security_getprocattr(struct task_struct *p, int lsmid, const char *name,
+ char **value)
{
struct security_hook_list *hp;
hlist_for_each_entry(hp, &security_hook_heads.getprocattr, list) {
- if (lsm != NULL && strcmp(lsm, hp->lsmid->name))
+ if (lsmid != 0 && lsmid != hp->lsmid->id)
continue;
return hp->hook.getprocattr(p, name, value);
}
@@ -3863,7 +3863,7 @@ int security_getprocattr(struct task_struct *p, const char *lsm,
/**
* security_setprocattr() - Set an attribute for a task
- * @lsm: LSM name
+ * @lsmid: LSM identification
* @name: attribute name
* @value: attribute value
* @size: attribute value size
@@ -3873,13 +3873,12 @@ int security_getprocattr(struct task_struct *p, const char *lsm,
*
* Return: Returns bytes written on success, a negative value otherwise.
*/
-int security_setprocattr(const char *lsm, const char *name, void *value,
- size_t size)
+int security_setprocattr(int lsmid, const char *name, void *value, size_t size)
{
struct security_hook_list *hp;
hlist_for_each_entry(hp, &security_hook_heads.setprocattr, list) {
- if (lsm != NULL && strcmp(lsm, hp->lsmid->name))
+ if (lsmid != 0 && lsmid != hp->lsmid->id)
continue;
return hp->hook.setprocattr(name, value, size);
}
--
2.41.0
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