1 files changed, 72 insertions, 16 deletions

diff --git a/mm/shmem.c b/mm/shmem.c
index b7e195571862..7cc80833b74a 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1178,6 +1178,12 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode
 static const struct inode_operations shmem_symlink_inode_operations;
 static const struct inode_operations shmem_short_symlink_operations;
 
+#ifdef CONFIG_TMPFS_XATTR
+static int shmem_initxattrs(struct inode *, const struct xattr *, void *);
+#else
+#define shmem_initxattrs NULL
+#endif
+
 static int
 shmem_write_begin(struct file *file, struct address_space *mapping,
                         loff_t pos, unsigned len, unsigned flags,
@@ -1490,7 +1496,7 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
         if (inode) {
                 error = security_inode_init_security(inode, dir,
                                                      &dentry->d_name,
-                                                     NULL, NULL);
+                                                     shmem_initxattrs, NULL);
                 if (error) {
                         if (error != -EOPNOTSUPP) {
                                 iput(inode);
@@ -1630,7 +1636,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
                 return -ENOSPC;
 
         error = security_inode_init_security(inode, dir, &dentry->d_name,
-                                             NULL, NULL);
+                                             shmem_initxattrs, NULL);
         if (error) {
                 if (error != -EOPNOTSUPP) {
                         iput(inode);
@@ -1704,6 +1710,66 @@ static void shmem_put_link(struct dentry *dentry, struct nameidata *nd, void *co
  * filesystem level, though.
  */
 
+/*
+ * Allocate new xattr and copy in the value; but leave the name to callers.
+ */
+static struct shmem_xattr *shmem_xattr_alloc(const void *value, size_t size)
+{
+        struct shmem_xattr *new_xattr;
+        size_t len;
+
+        /* wrap around? */
+        len = sizeof(*new_xattr) + size;
+        if (len <= sizeof(*new_xattr))
+                return NULL;
+
+        new_xattr = kmalloc(len, GFP_KERNEL);
+        if (!new_xattr)
+                return NULL;
+
+        new_xattr->size = size;
+        memcpy(new_xattr->value, value, size);
+        return new_xattr;
+}
+
+/*
+ * Callback for security_inode_init_security() for acquiring xattrs.
+ */
+static int shmem_initxattrs(struct inode *inode,
+                            const struct xattr *xattr_array,
+                            void *fs_info)
+{
+        struct shmem_inode_info *info = SHMEM_I(inode);
+        const struct xattr *xattr;
+        struct shmem_xattr *new_xattr;
+        size_t len;
+
+        for (xattr = xattr_array; xattr->name != NULL; xattr++) {
+                new_xattr = shmem_xattr_alloc(xattr->value, xattr->value_len);
+                if (!new_xattr)
+                        return -ENOMEM;
+
+                len = strlen(xattr->name) + 1;
+                new_xattr->name = kmalloc(XATTR_SECURITY_PREFIX_LEN + len,
+                                          GFP_KERNEL);
+                if (!new_xattr->name) {
+                        kfree(new_xattr);
+                        return -ENOMEM;
+                }
+
+                memcpy(new_xattr->name, XATTR_SECURITY_PREFIX,
+                       XATTR_SECURITY_PREFIX_LEN);
+                memcpy(new_xattr->name + XATTR_SECURITY_PREFIX_LEN,
+                       xattr->name, len);
+
+                spin_lock(&info->lock);
+                list_add(&new_xattr->list, &info->xattr_list);
+                spin_unlock(&info->lock);
+        }
+
+        return 0;
+}
+
 static int shmem_xattr_get(struct dentry *dentry, const char *name,
                            void *buffer, size_t size)
 {
@@ -1731,24 +1797,17 @@ static int shmem_xattr_get(struct dentry *dentry, const char *name,
         return ret;
 }
 
-static int shmem_xattr_set(struct dentry *dentry, const char *name,
+static int shmem_xattr_set(struct inode *inode, const char *name,
                            const void *value, size_t size, int flags)
 {
-        struct inode *inode = dentry->d_inode;
         struct shmem_inode_info *info = SHMEM_I(inode);
         struct shmem_xattr *xattr;
         struct shmem_xattr *new_xattr = NULL;
-        size_t len;
         int err = 0;
 
         /* value == NULL means remove */
         if (value) {
-                /* wrap around? */
-                len = sizeof(*new_xattr) + size;
-                if (len <= sizeof(*new_xattr))
-                        return -ENOMEM;
-
-                new_xattr = kmalloc(len, GFP_KERNEL);
+                new_xattr = shmem_xattr_alloc(value, size);
                 if (!new_xattr)
                         return -ENOMEM;
 
@@ -1757,9 +1816,6 @@ static int shmem_xattr_set(struct dentry *dentry, const char *name,
                         kfree(new_xattr);
                         return -ENOMEM;
                 }
-
-                new_xattr->size = size;
-                memcpy(new_xattr->value, value, size);
         }
 
         spin_lock(&info->lock);
@@ -1858,7 +1914,7 @@ static int shmem_setxattr(struct dentry *dentry, const char *name,
         if (size == 0)
                 value = "";  /* empty EA, do not remove */
 
-        return shmem_xattr_set(dentry, name, value, size, flags);
+        return shmem_xattr_set(dentry->d_inode, name, value, size, flags);
 
 }
 
@@ -1878,7 +1934,7 @@ static int shmem_removexattr(struct dentry *dentry, const char *name)
         if (err)
                 return err;
 
-        return shmem_xattr_set(dentry, name, NULL, 0, XATTR_REPLACE);
+        return shmem_xattr_set(dentry->d_inode, name, NULL, 0, XATTR_REPLACE);
 }
 
 static bool xattr_is_trusted(const char *name)