ksmbd: fix out of bounds in smb3_decrypt_req()

[ Upstream commit dc318846f3dd54574a36ae97fc8d8b75dd7cdb1e ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c
index 6d0896c76b098ef42f65e08e3658093154dff0ed..dab4c7d710914ed116077f393d958633cd36782e 100644 (file)
--- a/fs/smb/server/smb2pdu.c
+++ b/fs/smb/server/smb2pdu.c
@@ -8623,7 +8623,8 @@ 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;