Add PR_{GET,SET}_NO_NEW_PRIVS to prevent execve from granting privs

[deliverable/linux.git] / fs / exec.c

diff --git a/fs/exec.c b/fs/exec.c
index b1fd2025e59a1e0ea0a2f475b812987dac176e9f..d038968b54b420a3844c6e07f6bf25bee34d7e5c 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1245,6 +1245,13 @@ static int check_unsafe_exec(struct linux_binprm *bprm)
                        bprm->unsafe |= LSM_UNSAFE_PTRACE;
        }
 
+       /*
+        * This isn't strictly necessary, but it makes it harder for LSMs to
+        * mess up.
+        */
+       if (current->no_new_privs)
+               bprm->unsafe |= LSM_UNSAFE_NO_NEW_PRIVS;
+
        n_fs = 1;
        spin_lock(&p->fs->lock);
        rcu_read_lock();
@@ -1288,7 +1295,8 @@ int prepare_binprm(struct linux_binprm *bprm)
        bprm->cred->euid = current_euid();
        bprm->cred->egid = current_egid();
 
-       if (!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)) {
+       if (!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) &&
+           !current->no_new_privs) {
                /* Set-uid? */
                if (mode & S_ISUID) {
                        bprm->per_clear |= PER_CLEAR_ON_SETID;