CRED: Inaugurate COW credentials

[linux-2.6-omap-h63xx.git] / fs / exec.c

diff --git a/fs/exec.c b/fs/exec.c
index a5330e1a2216931aeb2f9901dc24def62e228435..9bd3559ddece2a764d6704cdde5b3270a1c6593a 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1007,13 +1007,12 @@ int flush_old_exec(struct linux_binprm * bprm)
         */
        current->mm->task_size = TASK_SIZE;
 
-       if (bprm->e_uid != current_euid() || bprm->e_gid != current_egid()) {
-               suid_keys(current);
+       if (bprm->e_uid != current_euid() ||
+           bprm->e_gid != current_egid()) {
                set_dumpable(current->mm, suid_dumpable);
                current->pdeath_signal = 0;
        } else if (file_permission(bprm->file, MAY_READ) ||
                        (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP)) {
-               suid_keys(current);
                set_dumpable(current->mm, suid_dumpable);
        }
 
@@ -1096,10 +1095,8 @@ void compute_creds(struct linux_binprm *bprm)
 {
        int unsafe;
 
-       if (bprm->e_uid != current_uid()) {
-               suid_keys(current);
+       if (bprm->e_uid != current_uid())
                current->pdeath_signal = 0;
-       }
        exec_keys(current);
 
        task_lock(current);
@@ -1709,8 +1706,9 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
        struct linux_binfmt * binfmt;
        struct inode * inode;
        struct file * file;
+       const struct cred *old_cred;
+       struct cred *cred;
        int retval = 0;
-       int fsuid = current_fsuid();
        int flag = 0;
        int ispipe = 0;
        unsigned long core_limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
@@ -1723,12 +1721,20 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
        binfmt = current->binfmt;
        if (!binfmt || !binfmt->core_dump)
                goto fail;
+
+       cred = prepare_creds();
+       if (!cred) {
+               retval = -ENOMEM;
+               goto fail;
+       }
+
        down_write(&mm->mmap_sem);
        /*
         * If another thread got here first, or we are not dumpable, bail out.
         */
        if (mm->core_state || !get_dumpable(mm)) {
                up_write(&mm->mmap_sem);
+               put_cred(cred);
                goto fail;
        }
 
@@ -1739,12 +1745,16 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
         */
        if (get_dumpable(mm) == 2) {    /* Setuid core dump mode */
                flag = O_EXCL;          /* Stop rewrite attacks */
-               current->cred->fsuid = 0;       /* Dump root private */
+               cred->fsuid = 0;        /* Dump root private */
        }
 
        retval = coredump_wait(exit_code, &core_state);
-       if (retval < 0)
+       if (retval < 0) {
+               put_cred(cred);
                goto fail;
+       }
+
+       old_cred = override_creds(cred);
 
        /*
         * Clear any false indication of pending signals that might
@@ -1835,7 +1845,8 @@ fail_unlock:
        if (helper_argv)
                argv_free(helper_argv);
 
-       current->cred->fsuid = fsuid;
+       revert_creds(old_cred);
+       put_cred(cred);
        coredump_finish(mm);
 fail:
        return retval;