Introduce helper function ext2_xattr_entry_valid()
for xattr entry validation and clean up the entry
check ralated code.
Signed-off-by: Chengguang Xu <cgxu519@xxxxxxxxxxx>
---
v1->v2:
- Pass end offset instead of inode to ext2_xattr_entry_valid()
- Change signed-off mail address.
fs/ext2/xattr.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)
diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c
index db27260d6a5b..d11c83529514 100644
--- a/fs/ext2/xattr.c
+++ b/fs/ext2/xattr.c
@@ -144,6 +144,20 @@ ext2_xattr_header_valid(struct ext2_xattr_header *header)
return true;
}
+static bool
+ext2_xattr_entry_valid(struct ext2_xattr_entry *entry, size_t size,
+ size_t end_offs)
+{
+ if (entry->e_value_block != 0)
+ return false;
+
+ if (size > end_offs ||
+ le16_to_cpu(entry->e_value_offs) + size > end_offs)
+ return false;
+
+ return true;
+}
+
/*
* ext2_xattr_get()
*
@@ -217,8 +231,7 @@ ext2_xattr_get(struct inode *inode, int name_index, const char *name,
if (entry->e_value_block != 0)
goto bad_block;
size = le32_to_cpu(entry->e_value_size);
- if (size > inode->i_sb->s_blocksize ||
- le16_to_cpu(entry->e_value_offs) + size > inode->i_sb->s_blocksize)
+ if (!ext2_xattr_entry_valid(entry, size, inode->i_sb->s_blocksize))
goto bad_block;
if (ext2_xattr_cache_insert(ea_block_cache, bh))
@@ -483,8 +496,8 @@ ext2_xattr_set(struct inode *inode, int name_index, const char *name,
if (!here->e_value_block && here->e_value_size) {
size_t size = le32_to_cpu(here->e_value_size);
- if (le16_to_cpu(here->e_value_offs) + size >
- sb->s_blocksize || size > sb->s_blocksize)
+ if (!ext2_xattr_entry_valid(here, size,
+ inode->i_sb->s_blocksize))
goto bad_block;
free += EXT2_XATTR_SIZE(size);
}
--
2.17.2
