Re: [libvirt] [PATCH] rpc: Correct the wrong payload size checking

<...> /* Size of message length field. Not counted in VIR_NET_MESSAGE_MAX * and VIR_NET_MESSAGE_INITIAL. */ const VIR_NET_MESSAGE_LEN_MAX = 4; </...> However, msg->bufferLength includes the length word. The wrong checking was introduced by commit e914dcfd. * src/rpc/virnetmessage.c: - Correct the checking in virNetMessageEncodePayloadRaw - Use a new variable to track the new payload length in virNetMessageEncodePayloadRaw --- src/rpc/virnetmessage.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/src/rpc/virnetmessage.c b/src/rpc/virnetmessage.c index 8f4e4bc..4c60424 100644 --- a/src/rpc/virnetmessage.c +++ b/src/rpc/virnetmessage.c @@ -346,15 +346,17 @@ int virNetMessageEncodePayload(virNetMessagePtr msg, /* Try to encode the payload. If the buffer is too small increase it. */ while (!(*filter)(&xdr, data)) { - if ((msg->bufferLength - VIR_NET_MESSAGE_LEN_MAX) * 4 > VIR_NET_MESSAGE_MAX) { + unsigned int newlen = (msg->bufferLength - VIR_NET_MESSAGE_LEN_MAX) * 4 + + VIR_NET_MESSAGE_LEN_MAX; + + if (newlen > VIR_NET_MESSAGE_MAX + VIR_NET_MESSAGE_LEN_MAX) {

virReportError(VIR_ERR_RPC, "%s", _("Unable to encode message payload")); goto error; } xdr_destroy(&xdr); - msg->bufferLength = (msg->bufferLength - VIR_NET_MESSAGE_LEN_MAX) * 4 + - VIR_NET_MESSAGE_LEN_MAX; + msg->bufferLength = newlen;

if (VIR_REALLOC_N(msg->buffer, msg->bufferLength) < 0) goto error; @@ -426,10 +428,15 @@ int virNetMessageEncodePayloadRaw(virNetMessagePtr msg, /* If the message buffer is too small for the payload increase it accordingly. */ if ((msg->bufferLength - msg->bufferOffset) < len) { - if ((msg->bufferOffset + len) > VIR_NET_MESSAGE_MAX) { + if ((msg->bufferOffset + len) > + VIR_NET_MESSAGE_MAX + VIR_NET_MESSAGE_LEN_MAX) {

virReportError(VIR_ERR_RPC, - _("Stream data too long to send (%zu bytes needed, %zu bytes available)"), - len, (VIR_NET_MESSAGE_MAX - msg->bufferOffset)); + _("Stream data too long to send " + "(%zu bytes needed, %zu bytes available)"), + len, + VIR_NET_MESSAGE_MAX + + VIR_NET_MESSAGE_LEN_MAX - + msg->bufferOffset); return -1;