1 files changed, 24 insertions, 8 deletions

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index da4df703c211..42823ab3718c 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -190,14 +190,28 @@ ext4_listxattr(struct dentry *dentry, char *buffer, size_t size)
 }
 
 static int
-ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end)
+ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end,
+                       void *value_start)
 {
-        while (!IS_LAST_ENTRY(entry)) {
-                struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(entry);
+        struct ext4_xattr_entry *e = entry;
+
+        while (!IS_LAST_ENTRY(e)) {
+                struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(e);
                 if ((void *)next >= end)
                         return -EIO;
-                entry = next;
+                e = next;
         }
+
+        while (!IS_LAST_ENTRY(entry)) {
+                if (entry->e_value_size != 0 &&
+                    (value_start + le16_to_cpu(entry->e_value_offs) <
+                     (void *)e + sizeof(__u32) ||
+                     value_start + le16_to_cpu(entry->e_value_offs) +
+                    le32_to_cpu(entry->e_value_size) > end))
+                        return -EIO;
+                entry = EXT4_XATTR_NEXT(entry);
+        }
+
         return 0;
 }
 
@@ -214,7 +228,8 @@ ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh)
                 return -EIO;
         if (!ext4_xattr_block_csum_verify(inode, bh->b_blocknr, BHDR(bh)))
                 return -EIO;
-        error = ext4_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size);
+        error = ext4_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size,
+                                       bh->b_data);
         if (!error)
                 set_buffer_verified(bh);
         return error;
@@ -331,7 +346,7 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
         header = IHDR(inode, raw_inode);
         entry = IFIRST(header);
         end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
-        error = ext4_xattr_check_names(entry, end);
+        error = ext4_xattr_check_names(entry, end, entry);
         if (error)
                 goto cleanup;
         error = ext4_xattr_find_entry(&entry, name_index, name,
@@ -463,7 +478,7 @@ ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
         raw_inode = ext4_raw_inode(&iloc);
         header = IHDR(inode, raw_inode);
         end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
-        error = ext4_xattr_check_names(IFIRST(header), end);
+        error = ext4_xattr_check_names(IFIRST(header), end, IFIRST(header));
         if (error)
                 goto cleanup;
         error = ext4_xattr_list_entries(dentry, IFIRST(header),
@@ -980,7 +995,8 @@ int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
         is->s.here = is->s.first;
         is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
         if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
-                error = ext4_xattr_check_names(IFIRST(header), is->s.end);
+                error = ext4_xattr_check_names(IFIRST(header), is->s.end,
+                                               IFIRST(header));
                 if (error)
                         return error;
                 /* Find the named attribute. */