1 files changed, 40 insertions, 12 deletions

diff --git a/fs/exec.c b/fs/exec.c
index 929b58004b7e..052a961e41aa 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -45,6 +45,7 @@
 #include <linux/proc_fs.h>
 #include <linux/mount.h>
 #include <linux/security.h>
+#include <linux/ima.h>
 #include <linux/syscalls.h>
 #include <linux/tsacct_kern.h>
 #include <linux/cn_proc.h>
@@ -52,6 +53,7 @@
 #include <linux/tracehook.h>
 #include <linux/kmod.h>
 #include <linux/fsnotify.h>
+#include <linux/fs_struct.h>
 
 #include <asm/uaccess.h>
 #include <asm/mmu_context.h>
@@ -127,6 +129,9 @@ SYSCALL_DEFINE1(uselib, const char __user *, library)
                                  MAY_READ | MAY_EXEC | MAY_OPEN);
         if (error)
                 goto exit;
+        error = ima_path_check(&nd.path, MAY_READ | MAY_EXEC | MAY_OPEN);
+        if (error)
+                goto exit;
 
         file = nameidata_to_filp(&nd, O_RDONLY|O_LARGEFILE);
         error = PTR_ERR(file);
@@ -674,6 +679,9 @@ struct file *open_exec(const char *name)
         err = inode_permission(nd.path.dentry->d_inode, MAY_EXEC | MAY_OPEN);
         if (err)
                 goto out_path_put;
+        err = ima_path_check(&nd.path, MAY_EXEC | MAY_OPEN);
+        if (err)
+                goto out_path_put;
 
         file = nameidata_to_filp(&nd, O_RDONLY|O_LARGEFILE);
         if (IS_ERR(file))
@@ -1049,32 +1057,35 @@ EXPORT_SYMBOL(install_exec_creds);
  * - the caller must hold current->cred_exec_mutex to protect against
  *   PTRACE_ATTACH
  */
-void check_unsafe_exec(struct linux_binprm *bprm, struct files_struct *files)
+int check_unsafe_exec(struct linux_binprm *bprm)
 {
         struct task_struct *p = current, *t;
         unsigned long flags;
-        unsigned n_fs, n_files, n_sighand;
+        unsigned n_fs;
+        int res = 0;
 
         bprm->unsafe = tracehook_unsafe_exec(p);
 
         n_fs = 1;
-        n_files = 1;
-        n_sighand = 1;
+        write_lock(&p->fs->lock);
         lock_task_sighand(p, &flags);
         for (t = next_thread(p); t != p; t = next_thread(t)) {
                 if (t->fs == p->fs)
                         n_fs++;
-                if (t->files == files)
-                        n_files++;
-                n_sighand++;
         }
 
-        if (atomic_read(&p->fs->count) > n_fs ||
-            atomic_read(&p->files->count) > n_files ||
-            atomic_read(&p->sighand->count) > n_sighand)
+        if (p->fs->users > n_fs) {
                 bprm->unsafe |= LSM_UNSAFE_SHARE;
+        } else {
+                if (p->fs->in_exec)
+                        res = -EAGAIN;
+                p->fs->in_exec = 1;
+        }
 
         unlock_task_sighand(p, &flags);
+        write_unlock(&p->fs->lock);
+
+        return res;
 }
 
 /* 
@@ -1184,6 +1195,9 @@ int search_binary_handler(struct linux_binprm *bprm,struct pt_regs *regs)
         retval = security_bprm_check(bprm);
         if (retval)
                 return retval;
+        retval = ima_bprm_check(bprm);
+        if (retval)
+                return retval;
 
         /* kernel module loader fixup */
         /* so we don't try to load run modprobe in kernel space. */
@@ -1284,17 +1298,21 @@ int do_execve(char * filename,
         retval = mutex_lock_interruptible(&current->cred_exec_mutex);
         if (retval < 0)
                 goto out_free;
+        current->in_execve = 1;
 
         retval = -ENOMEM;
         bprm->cred = prepare_exec_creds();
         if (!bprm->cred)
                 goto out_unlock;
-        check_unsafe_exec(bprm, displaced);
+
+        retval = check_unsafe_exec(bprm);
+        if (retval)
+                goto out_unlock;
 
         file = open_exec(filename);
         retval = PTR_ERR(file);
         if (IS_ERR(file))
-                goto out_unlock;
+                goto out_unmark;
 
         sched_exec();
 
@@ -1337,6 +1355,10 @@ int do_execve(char * filename,
                 goto out;
 
         /* execve succeeded */
+        write_lock(&current->fs->lock);
+        current->fs->in_exec = 0;
+        write_unlock(&current->fs->lock);
+        current->in_execve = 0;
         mutex_unlock(&current->cred_exec_mutex);
         acct_update_integrals(current);
         free_bprm(bprm);
@@ -1354,7 +1376,13 @@ out_file:
                 fput(bprm->file);
         }
 
+out_unmark:
+        write_lock(&current->fs->lock);
+        current->fs->in_exec = 0;
+        write_unlock(&current->fs->lock);
+
 out_unlock:
+        current->in_execve = 0;
         mutex_unlock(&current->cred_exec_mutex);
 
 out_free: