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>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 4eec399ec807..c6ae6fab99be 100644
--- 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);