[PATCH] ksmbd: validate compound response buffer

Namjae Jeon
2021-10-12T01:20:20Z

Add the check to validate compound response buffer.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
---
fs/ksmbd/smb2pdu.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 7b4689f2df49..89c187aa8db2 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -449,6 +449,12 @@ bool is_chained_smb2_message(struct ksmbd_work *work)
return false;
}

+ if ((u64)get_rfc1002_len(work->response_buf) + MAX_CIFS_SMALL_BUFFER_SIZE >
+ work->response_sz) {
+ pr_err("next response offset exceeds response buffer size\n");
+ return false;
+ }
+
ksmbd_debug(SMB, "got SMB2 chained command\n");
init_chained_smb2_rsp(work);
return true;
--
2.25.1