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authorChengguang Xu <cgxu519@zoho.com.cn>2019-05-14 06:40:42 +0800
committerJan Kara <jack@suse.cz>2019-05-20 10:50:48 +0200
commitf4c3fb8c433f1818da46b720754a5d4a8525fdf0 (patch)
tree74dda3d85cfd5d1cf864a784c3cacc20c7c94f01 /fs/ext2
parent02475de9bb23ed5381f0fb04a84a3c4fad90582d (diff)
ext2: introduce helper for xattr entry validation
Introduce helper function ext2_xattr_entry_valid() for xattr entry validation and clean up the entry check related code. Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Chengguang Xu <cgxu519@zoho.com.cn> Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/ext2')
-rw-r--r--fs/ext2/xattr.c32
1 files changed, 21 insertions, 11 deletions
diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c
index db27260d6a5b..fb2e008d4406 100644
--- a/fs/ext2/xattr.c
+++ b/fs/ext2/xattr.c
@@ -144,6 +144,22 @@ ext2_xattr_header_valid(struct ext2_xattr_header *header)
return true;
}
+static bool
+ext2_xattr_entry_valid(struct ext2_xattr_entry *entry, size_t end_offs)
+{
+ size_t size;
+
+ if (entry->e_value_block != 0)
+ return false;
+
+ size = le32_to_cpu(entry->e_value_size);
+ if (size > end_offs ||
+ le16_to_cpu(entry->e_value_offs) + size > end_offs)
+ return false;
+
+ return true;
+}
+
/*
* ext2_xattr_get()
*
@@ -213,14 +229,10 @@ bad_block:
error = -ENODATA;
goto cleanup;
found:
- /* check the buffer size */
- 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, inode->i_sb->s_blocksize))
goto bad_block;
+ size = le32_to_cpu(entry->e_value_size);
if (ext2_xattr_cache_insert(ea_block_cache, bh))
ea_idebug(inode, "cache insert failed");
if (buffer) {
@@ -481,12 +493,10 @@ bad_block:
if (flags & XATTR_CREATE)
goto cleanup;
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, sb->s_blocksize))
goto bad_block;
- free += EXT2_XATTR_SIZE(size);
+ free += EXT2_XATTR_SIZE(
+ le32_to_cpu(here->e_value_size));
}
free += EXT2_XATTR_LEN(name_len);
}