[PATCH AUTOSEL 5.15 06/31] ksmbd: fix out of bounds in smb3_decrypt_req()

[Sasha Levin]

From: Namjae Jeon <linkinjeon@xxxxxxxxxx>

[ Upstream commit dc318846f3dd54574a36ae97fc8d8b75dd7cdb1e ]

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

Reported-by: zdi-disclosures@xxxxxxxxxxxxxx # ZDI-CAN-21589
Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/ksmbd/smb2pdu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 9f9d07caa57e9..a4673831fc10d 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -8642,7 +8642,8 @@ int smb3_decrypt_req(struct ksmbd_work *work)
 	struct smb2_transform_hdr *tr_hdr = (struct smb2_transform_hdr *)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;
-- 
2.40.1