ext4: avoid unneeded lookup when xattr name is invalid

In ext4_xattr_set_handle() we have checked the xattr name's length. So
we should also check it in ext4_xattr_get() to avoid unneeded lookup
caused by invalid name.

Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 4eec399ec807bc6733d1a90b8c3d0d205eb795c1..c6ae6fab99befc751015f7b2e4e8f0ed06653d1c 100644 (file)
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -369,6 +369,9 @@ ext4_xattr_get(struct inode *inode, int name_index, const char *name,
 {
        int error;
 
+       if (strlen(name) > 255)
+               return -ERANGE;
+
        down_read(&EXT4_I(inode)->xattr_sem);
        error = ext4_xattr_ibody_get(inode, name_index, name, buffer,
                                     buffer_size);