split ->file_mmap() into ->mmap_addr()/->mmap_file()

... i.e. file-dependent and address-dependent checks.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

11 files changed, 64 insertions, 78 deletions

diff --git a/fs/exec.c b/fs/exec.c
index 52c9e2ff6e6b..a79786a8d2c8 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -280,10 +280,6 @@ static int __bprm_mm_init(struct linux_binprm *bprm)
         vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
         INIT_LIST_HEAD(&vma->anon_vma_chain);
 
-        err = security_file_mmap(NULL, 0, 0, 0, vma->vm_start, 1);
-        if (err)
-                goto err;
-
         err = insert_vm_struct(mm, vma);
         if (err)
                 goto err;
diff --git a/include/linux/security.h b/include/linux/security.h
index 4ad59c9fa731..f1bae0963ddc 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -87,9 +87,8 @@ extern int cap_inode_removexattr(struct dentry *dentry, const char *name);
 extern int cap_inode_need_killpriv(struct dentry *dentry);
 extern int cap_inode_killpriv(struct dentry *dentry);
 extern int cap_mmap_addr(unsigned long addr);
-extern int cap_file_mmap(struct file *file, unsigned long reqprot,
-                         unsigned long prot, unsigned long flags,
-                         unsigned long addr, unsigned long addr_only);
+extern int cap_mmap_file(struct file *file, unsigned long reqprot,
+                         unsigned long prot, unsigned long flags);
 extern int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags);
 extern int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3,
                           unsigned long arg4, unsigned long arg5);
@@ -587,15 +586,17 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
  *      simple integer value.  When @arg represents a user space pointer, it
  *      should never be used by the security module.
  *      Return 0 if permission is granted.
- * @file_mmap :
+ * @mmap_addr :
+ *      Check permissions for a mmap operation at @addr.
+ *      @addr contains virtual address that will be used for the operation.
+ *      Return 0 if permission is granted.
+ * @mmap_file :
  *      Check permissions for a mmap operation.  The @file may be NULL, e.g.
  *      if mapping anonymous memory.
  *      @file contains the file structure for file to map (may be NULL).
  *      @reqprot contains the protection requested by the application.
  *      @prot contains the protection that will be applied by the kernel.
  *      @flags contains the operational flags.
- *      @addr contains virtual address that will be used for the operation.
- *      @addr_only contains a boolean: 0 if file-backed VMA, otherwise 1.
  *      Return 0 if permission is granted.
  * @file_mprotect:
  *      Check permissions before changing memory access permissions.
@@ -1482,10 +1483,10 @@ struct security_operations {
         void (*file_free_security) (struct file *file);
         int (*file_ioctl) (struct file *file, unsigned int cmd,
                            unsigned long arg);
-        int (*file_mmap) (struct file *file,
+        int (*mmap_addr) (unsigned long addr);
+        int (*mmap_file) (struct file *file,
                           unsigned long reqprot, unsigned long prot,
-                          unsigned long flags, unsigned long addr,
-                          unsigned long addr_only);
+                          unsigned long flags);
         int (*file_mprotect) (struct vm_area_struct *vma,
                               unsigned long reqprot,
                               unsigned long prot);
@@ -1744,9 +1745,9 @@ int security_file_permission(struct file *file, int mask);
 int security_file_alloc(struct file *file);
 void security_file_free(struct file *file);
 int security_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
-int security_file_mmap(struct file *file, unsigned long reqprot,
-                        unsigned long prot, unsigned long flags,
-                        unsigned long addr, unsigned long addr_only);
+int security_mmap_file(struct file *file, unsigned long reqprot,
+                        unsigned long prot, unsigned long flags);
+int security_mmap_addr(unsigned long addr);
 int security_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
                            unsigned long prot);
 int security_file_lock(struct file *file, unsigned int cmd);
@@ -2182,11 +2183,14 @@ static inline int security_file_ioctl(struct file *file, unsigned int cmd,
         return 0;
 }
 
-static inline int security_file_mmap(struct file *file, unsigned long reqprot,
+static inline int security_mmap_file(struct file *file, unsigned long reqprot,
                                      unsigned long prot,
-                                     unsigned long flags,
-                                     unsigned long addr,
-                                     unsigned long addr_only)
+                                     unsigned long flags)
+{
+        return 0;
+}
+
+static inline int security_mmap_addr(unsigned long addr)
 {
         return cap_mmap_addr(addr);
 }
diff --git a/mm/mmap.c b/mm/mmap.c
index 83c56624f1f6..49283da9a2ae 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1101,7 +1101,11 @@ static unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
                 }
         }
 
-        error = security_file_mmap(file, reqprot, prot, flags, addr, 0);
+        error = security_mmap_addr(addr);
+        if (error)
+                return error;
+
+        error = security_mmap_file(file, reqprot, prot, flags);
         if (error)
                 return error;
 
@@ -1817,7 +1821,7 @@ int expand_downwards(struct vm_area_struct *vma,
                 return -ENOMEM;
 
         address &= PAGE_MASK;
-        error = security_file_mmap(NULL, 0, 0, 0, address, 1);
+        error = security_mmap_addr(address);
         if (error)
                 return error;
 
@@ -2205,7 +2209,7 @@ static unsigned long do_brk(unsigned long addr, unsigned long len)
         if (!len)
                 return addr;
 
-        error = security_file_mmap(NULL, 0, 0, 0, addr, 1);
+        error = security_mmap_addr(addr);
         if (error)
                 return error;
 
@@ -2561,7 +2565,7 @@ int install_special_mapping(struct mm_struct *mm,
         vma->vm_ops = &special_mapping_vmops;
         vma->vm_private_data = pages;
 
-        ret = security_file_mmap(NULL, 0, 0, 0, vma->vm_start, 1);
+        ret = security_mmap_addr(vma->vm_start);
         if (ret)
                 goto out;
 
diff --git a/mm/mremap.c b/mm/mremap.c
index 169c53b87749..ebf10892b63d 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -371,7 +371,7 @@ static unsigned long mremap_to(unsigned long addr,
         if ((addr <= new_addr) && (addr+old_len) > new_addr)
                 goto out;
 
-        ret = security_file_mmap(NULL, 0, 0, 0, new_addr, 1);
+        ret = security_mmap_addr(new_addr);
         if (ret)
                 goto out;
 
@@ -532,7 +532,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
                         goto out;
                 }