ksmbd: fix out of bounds in smb3_decrypt_req()

smb3_decrypt_req() validate if pdu_length is smaller than
smb2_transform_hdr size.

Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-21589
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c
index ca27663..3eb5d4d 100644 (file)
--- a/fs/smb/server/smb2pdu.c
+++ b/fs/smb/server/smb2pdu.c
@@ -8614,7 +8614,8 @@ int smb3_decrypt_req(struct ksmbd_work *work)
        struct smb2_transform_hdr *tr_hdr = smb2_get_msg(buf);
        int rc = 0;
 
-       if (buf_data_size < sizeof(struct smb2_hdr)) {
+       if (pdu_length < sizeof(struct smb2_transform_hdr) ||
+           buf_data_size < sizeof(struct smb2_hdr)) {
                pr_err("Transform message is too small (%u)\n",
                       pdu_length);
                return -ECONNABORTED;