1 files changed, 60 insertions, 50 deletions

diff --git a/fs/namei.c b/fs/namei.c
index f3c5b278895a..d11f404667e9 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -169,19 +169,10 @@ void putname(const char *name)
 EXPORT_SYMBOL(putname);
 #endif
 
-
-/**
- * generic_permission  -  check for access rights on a Posix-like filesystem
- * @inode:      inode to check access rights for
- * @mask:       right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
- * @check_acl:  optional callback to check for Posix ACLs
- *
- * Used to check for read/write/execute permissions on a file.
- * We use "fsuid" for this, letting us set arbitrary permissions
- * for filesystem access without changing the "normal" uids which
- * are used for other things..
+/*
+ * This does basic POSIX ACL permission checking
  */
-int generic_permission(struct inode *inode, int mask,
+static int acl_permission_check(struct inode *inode, int mask,
                 int (*check_acl)(struct inode *inode, int mask))
 {
         umode_t                 mode = inode->i_mode;
@@ -193,9 +184,7 @@ int generic_permission(struct inode *inode, int mask,
         else {
                 if (IS_POSIXACL(inode) && (mode & S_IRWXG) && check_acl) {
                         int error = check_acl(inode, mask);
-                        if (error == -EACCES)
-                                goto check_capabilities;
-                        else if (error != -EAGAIN)
+                        if (error != -EAGAIN)
                                 return error;
                 }
 
@@ -208,8 +197,32 @@ int generic_permission(struct inode *inode, int mask,
          */
         if ((mask & ~mode) == 0)
                 return 0;
+        return -EACCES;
+}
+
+/**
+ * generic_permission  -  check for access rights on a Posix-like filesystem
+ * @inode:      inode to check access rights for
+ * @mask:       right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC)
+ * @check_acl:  optional callback to check for Posix ACLs
+ *
+ * Used to check for read/write/execute permissions on a file.
+ * We use "fsuid" for this, letting us set arbitrary permissions
+ * for filesystem access without changing the "normal" uids which
+ * are used for other things..
+ */
+int generic_permission(struct inode *inode, int mask,
+                int (*check_acl)(struct inode *inode, int mask))
+{
+        int ret;
+
+        /*
+         * Do the basic POSIX ACL permission checks.
+         */
+        ret = acl_permission_check(inode, mask, check_acl);
+        if (ret != -EACCES)
+                return ret;
 
- check_capabilities:
         /*
          * Read/write DACs are always overridable.
          * Executable DACs are overridable if at least one exec bit is set.
@@ -262,7 +275,7 @@ int inode_permission(struct inode *inode, int mask)
         if (inode->i_op->permission)
                 retval = inode->i_op->permission(inode, mask);
         else
-                retval = generic_permission(inode, mask, NULL);
+                retval = generic_permission(inode, mask, inode->i_op->check_acl);
 
         if (retval)
                 return retval;
@@ -432,29 +445,22 @@ static struct dentry * cached_lookup(struct dentry * parent, struct qstr * name,
  */
 static int exec_permission_lite(struct inode *inode)
 {
-        umode_t mode = inode->i_mode;
+        int ret;
 
-        if (inode->i_op->permission)
-                return -EAGAIN;
-
-        if (current_fsuid() == inode->i_uid)
-                mode >>= 6;
-        else if (in_group_p(inode->i_gid))
-                mode >>= 3;
-
-        if (mode & MAY_EXEC)
-                goto ok;
-
-        if ((inode->i_mode & S_IXUGO) && capable(CAP_DAC_OVERRIDE))
-                goto ok;
-
-        if (S_ISDIR(inode->i_mode) && capable(CAP_DAC_OVERRIDE))
+        if (inode->i_op->permission) {
+                ret = inode->i_op->permission(inode, MAY_EXEC);
+                if (!ret)
+                        goto ok;
+                return ret;
+        }
+        ret = acl_permission_check(inode, MAY_EXEC, inode->i_op->check_acl);
+        if (!ret)
                 goto ok;
 
-        if (S_ISDIR(inode->i_mode) && capable(CAP_DAC_READ_SEARCH))
+        if (capable(CAP_DAC_OVERRIDE) || capable(CAP_DAC_READ_SEARCH))
                 goto ok;
 
-        return -EACCES;
+        return ret;
 ok:
         return security_inode_permission(inode, MAY_EXEC);
 }
@@ -853,12 +859,6 @@ static int __link_path_walk(const char *name, struct nameidata *nd)
 
                 nd->flags |= LOOKUP_CONTINUE;
                 err = exec_permission_lite(inode);
-                if (err == -EAGAIN)
-                        err = inode_permission(nd->path.dentry->d_inode,
-                                               MAY_EXEC);
-                if (!err)
-                        err = ima_path_check(&nd->path, MAY_EXEC,
-                                             IMA_COUNT_UPDATE);
                 if (err)
                         break;
 
@@ -1533,37 +1533,42 @@ int may_open(struct path *path, int acc_mode, int flag)
         if (error)
                 return error;
 
-        error = ima_path_check(path,
-                               acc_mode & (MAY_READ | MAY_WRITE | MAY_EXEC),
+        error = ima_path_check(path, acc_mode ?
+                               acc_mode & (MAY_READ | MAY_WRITE | MAY_EXEC) :
+                               ACC_MODE(flag) & (MAY_READ | MAY_WRITE),
                                IMA_COUNT_UPDATE);
+
         if (error)
                 return error;
         /*
          * An append-only file must be opened in append mode for writing.
          */
         if (IS_APPEND(inode)) {
+                error = -EPERM;
                 if  ((flag & FMODE_WRITE) && !(flag & O_APPEND))
-                        return -EPERM;
+                        goto err_out;
                 if (flag & O_TRUNC)
-                        return -EPERM;
+                        goto err_out;
         }
 
         /* O_NOATIME can only be set by the owner or superuser */
         if (flag & O_NOATIME)
-                if (!is_owner_or_cap(inode))
-                        return -EPERM;
+                if (!is_owner_or_cap(inode)) {
+                        error = -EPERM;
+                        goto err_out;
+                }
 
         /*
          * Ensure there are no outstanding leases on the file.
          */
         error = break_lease(inode, flag);
         if (error)
-                return error;
+                goto err_out;
 
         if (flag & O_TRUNC) {
                 error = get_write_access(inode);
                 if (error)
-                        return error;
+                        goto err_out;
 
                 /*
                  * Refuse to truncate files with mandatory locks held on them.
@@ -1581,12 +1586,17 @@ int may_open(struct path *path, int acc_mode, int flag)
                 }
                 put_write_access(inode);
                 if (error)
-                        return error;
+                        goto err_out;
         } else
                 if (flag & FMODE_WRITE)
                         vfs_dq_init(inode);
 
         return 0;
+err_out:
+        ima_counts_put(path, acc_mode ?
+                       acc_mode & (MAY_READ | MAY_WRITE | MAY_EXEC) :
+                       ACC_MODE(flag) & (MAY_READ | MAY_WRITE));
+        return error;
 }
 
 /*