sctp: correct bounds check in sctp_setsockopt_auth_key
The bonds check to prevent buffer overlflow was not exactly
right. It still allowed overflow of up to 8 bytes which is
sizeof(struct sctp_authkey).
Since optlen is already checked against the size of that struct,
we are guaranteed not to cause interger overflow either.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index afa952e..9b9b2c3 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -3144,7 +3144,7 @@
goto out;
}
- if (authkey->sca_keylength > optlen) {
+ if (authkey->sca_keylength > optlen - sizeof(struct sctp_authkey)) {
ret = -EINVAL;
goto out;
}