lsm: constify 'bprm' parameter in security_bprm_committing_creds()

The 'bprm_committing_creds' hook has implementations registered in
SELinux and Apparmor. Looking at the function implementations we observe
that the 'bprm' parameter is not changing.

Mark the 'bprm' parameter of LSM hook security_bprm_committing_creds()
as 'const' since it will not be changing in the LSM hook.

Signed-off-by: Khadija Kamran <kamrankhadijadj@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

Author: KhadijaKamran

include/linux/lsm_hook_defs.h

@@ -52,7 +52,7 @@ LSM_HOOK(int, 0, vm_enough_memory, struct mm_struct *mm, long pages)
 LSM_HOOK(int, 0, bprm_creds_for_exec, struct linux_binprm *bprm)
 LSM_HOOK(int, 0, bprm_creds_from_file, struct linux_binprm *bprm, const struct file *file)
 LSM_HOOK(int, 0, bprm_check_security, struct linux_binprm *bprm)
-LSM_HOOK(void, LSM_RET_VOID, bprm_committing_creds, struct linux_binprm *bprm)
+LSM_HOOK(void, LSM_RET_VOID, bprm_committing_creds, const struct linux_binprm *bprm)
 LSM_HOOK(void, LSM_RET_VOID, bprm_committed_creds, struct linux_binprm *bprm)
 LSM_HOOK(int, 0, fs_context_submount, struct fs_context *fc, struct super_block *reference)
 LSM_HOOK(int, 0, fs_context_dup, struct fs_context *fc,

include/linux/security.h

@@ -292,7 +292,7 @@ int security_vm_enough_memory_mm(struct mm_struct *mm, long pages);
 int security_bprm_creds_for_exec(struct linux_binprm *bprm);
 int security_bprm_creds_from_file(struct linux_binprm *bprm, const struct file *file);
 int security_bprm_check(struct linux_binprm *bprm);
-void security_bprm_committing_creds(struct linux_binprm *bprm);
+void security_bprm_committing_creds(const struct linux_binprm *bprm);
 void security_bprm_committed_creds(struct linux_binprm *bprm);
 int security_fs_context_submount(struct fs_context *fc, struct super_block *reference);
 int security_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc);
@@ -623,7 +623,7 @@ static inline int security_bprm_check(struct linux_binprm *bprm)
 	return 0;
 }
 
-static inline void security_bprm_committing_creds(struct linux_binprm *bprm)
+static inline void security_bprm_committing_creds(const struct linux_binprm *bprm)
 {
 }
 

security/apparmor/lsm.c

@@ -734,7 +734,7 @@ static int apparmor_setprocattr(const char *name, void *value,
  * apparmor_bprm_committing_creds - do task cleanup on committing new creds
  * @bprm: binprm for the exec  (NOT NULL)
  */
-static void apparmor_bprm_committing_creds(struct linux_binprm *bprm)
+static void apparmor_bprm_committing_creds(const struct linux_binprm *bprm)
 {
 	struct aa_label *label = aa_current_raw_label();
 	struct aa_label *new_label = cred_label(bprm->cred);

security/security.c

@@ -1118,7 +1118,7 @@ int security_bprm_check(struct linux_binprm *bprm)
  * open file descriptors to which access will no longer be granted when the
  * attributes are changed.  This is called immediately before commit_creds().
  */
-void security_bprm_committing_creds(struct linux_binprm *bprm)
+void security_bprm_committing_creds(const struct linux_binprm *bprm)
 {
 	call_void_hook(bprm_committing_creds, bprm);
 }

security/selinux/hooks.c

@@ -2455,7 +2455,7 @@ static inline void flush_unauthorized_files(const struct cred *cred,
 /*
  * Prepare a process for imminent new credential changes due to exec
  */
-static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
+static void selinux_bprm_committing_creds(const struct linux_binprm *bprm)
 {
 	struct task_security_struct *new_tsec;
 	struct rlimit *rlim, *initrlim;