lsm: constify the 'target' parameter in security_capget()

Three LSMs register the implementations for the "capget" hook: AppArmor,
SELinux, and the normal capability code. Looking at the function
implementations we may observe that the first parameter "target" is not
changing.

Mark the first argument "target" of LSM hook security_capget() as
"const" since it will not be changing in the LSM hook.

cap_capget() LSM hook declaration exceeds the 80 characters per line
limit. Split the function declaration to multiple lines to decrease the
line length.

Signed-off-by: Khadija Kamran <kamrankhadijadj@gmail.com>
Acked-by: John Johansen <john.johansen@canonical.com>
[PM: align the cap_capget() declaration, spelling fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>

diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index 920d8f16fa9976ba489763bff2505ac23de42128..540caa7035738db4ac08a07159237c74a73d457e 100644 (file)
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -36,7 +36,7 @@ LSM_HOOK(int, 0, binder_transfer_file, const struct cred *from,
 LSM_HOOK(int, 0, ptrace_access_check, struct task_struct *child,
         unsigned int mode)
 LSM_HOOK(int, 0, ptrace_traceme, struct task_struct *parent)
-LSM_HOOK(int, 0, capget, struct task_struct *target, kernel_cap_t *effective,
+LSM_HOOK(int, 0, capget, const struct task_struct *target, kernel_cap_t *effective,
         kernel_cap_t *inheritable, kernel_cap_t *permitted)
 LSM_HOOK(int, 0, capset, struct cred *new, const struct cred *old,
         const kernel_cap_t *effective, const kernel_cap_t *inheritable,

diff --git a/include/linux/security.h b/include/linux/security.h
index 32828502f09eae3383e854e0ed62541dd28c9303..7665f56d920a8b654ad2dd4a5756941e647fabdd 100644 (file)
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -145,7 +145,8 @@ extern int cap_capable(const struct cred *cred, struct user_namespace *ns,
 extern int cap_settime(const struct timespec64 *ts, const struct timezone *tz);
 extern int cap_ptrace_access_check(struct task_struct *child, unsigned int mode);
 extern int cap_ptrace_traceme(struct task_struct *parent);
-extern int cap_capget(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted);
+extern int cap_capget(const struct task_struct *target, kernel_cap_t *effective,
+                     kernel_cap_t *inheritable, kernel_cap_t *permitted);
 extern int cap_capset(struct cred *new, const struct cred *old,
                      const kernel_cap_t *effective,
                      const kernel_cap_t *inheritable,
@@ -271,7 +272,7 @@ int security_binder_transfer_file(const struct cred *from,
                                  const struct cred *to, struct file *file);
 int security_ptrace_access_check(struct task_struct *child, unsigned int mode);
 int security_ptrace_traceme(struct task_struct *parent);
-int security_capget(struct task_struct *target,
+int security_capget(const struct task_struct *target,
                    kernel_cap_t *effective,
                    kernel_cap_t *inheritable,
                    kernel_cap_t *permitted);
@@ -553,7 +554,7 @@ static inline int security_ptrace_traceme(struct task_struct *parent)
        return cap_ptrace_traceme(parent);
 }
 
-static inline int security_capget(struct task_struct *target,
+static inline int security_capget(const struct task_struct *target,
                                   kernel_cap_t *effective,
                                   kernel_cap_t *inheritable,
                                   kernel_cap_t *permitted)

diff --git a/kernel/capability.c b/kernel/capability.c
index 1a2795102ae46c4e60d3871f7d60bcd0cc9bee4f..dac4df77e376ec01268528f1464c52064861f89a 100644 (file)
--- a/kernel/capability.c
+++ b/kernel/capability.c
@@ -112,7 +112,7 @@ static inline int cap_get_target_pid(pid_t pid, kernel_cap_t *pEp,
        int ret;
 
        if (pid && (pid != task_pid_vnr(current))) {
-               struct task_struct *target;
+               const struct task_struct *target;
 
                rcu_read_lock();
 

diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index c9463bd0307df2c9cc99fffd7f2d0676cbfb99a9..108eccc5ada5847ee9687c1886f416f9ccdff72f 100644 (file)
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -144,7 +144,7 @@ static int apparmor_ptrace_traceme(struct task_struct *parent)
 }
 
 /* Derived from security/commoncap.c:cap_capget */
-static int apparmor_capget(struct task_struct *target, kernel_cap_t *effective,
+static int apparmor_capget(const struct task_struct *target, kernel_cap_t *effective,
                           kernel_cap_t *inheritable, kernel_cap_t *permitted)
 {
        struct aa_label *label;

diff --git a/security/commoncap.c b/security/commoncap.c
index ab5742ab4362b6a71c806ae615e929618e650160..bc05211041979c120831742d25f2e6133435166c 100644 (file)
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -197,7 +197,7 @@ out:
  * This function retrieves the capabilities of the nominated task and returns
  * them to the caller.
  */
-int cap_capget(struct task_struct *target, kernel_cap_t *effective,
+int cap_capget(const struct task_struct *target, kernel_cap_t *effective,
               kernel_cap_t *inheritable, kernel_cap_t *permitted)
 {
        const struct cred *cred;

diff --git a/security/security.c b/security/security.c
index 9177fd0968bd9081d4cbd813379eb5f9f3890535..6962ea38a98f8eb40350d20f2fe04aff8a8d7490 100644 (file)
--- a/security/security.c
+++ b/security/security.c
@@ -894,7 +894,7 @@ int security_ptrace_traceme(struct task_struct *parent)
  *
  * Return: Returns 0 if the capability sets were successfully obtained.
  */
-int security_capget(struct task_struct *target,
+int security_capget(const struct task_struct *target,
                    kernel_cap_t *effective,
                    kernel_cap_t *inheritable,
                    kernel_cap_t *permitted)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index a0787f07d7452c0d7610d4588f70572452a32915..c816dc5de627854d6aa63432c91662656b19a90b 100644 (file)
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2082,7 +2082,7 @@ static int selinux_ptrace_traceme(struct task_struct *parent)
                            SECCLASS_PROCESS, PROCESS__PTRACE, NULL);
 }
 
-static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
+static int selinux_capget(const struct task_struct *target, kernel_cap_t *effective,
                          kernel_cap_t *inheritable, kernel_cap_t *permitted)
 {
        return avc_has_perm(current_sid(), task_sid_obj(target),