BUG/MEDIUM: h3: fix use-after-free on mux Rx buffer wrapping

Handle wrapping buffer in h3_data_to_htx(). If data is wrapping, first
copy the contiguous data, then copy the data in front of the buffer.

Note that h3_headers_to_htx() is not able to handle wrapping data. For
the moment, a BUG_ON was added as a reminder. This cas never happened,
most probably because HEADERS is the first frame of the stream.
This commit is contained in:
Amaury Denoyelle 2022-04-27 14:41:53 +02:00
parent 0fa14a69e8
commit 30f23f53d2

View File

@ -112,6 +112,8 @@ static int h3_headers_to_htx(struct qcs *qcs, struct buffer *buf, uint64_t len,
struct ist authority = IST_NULL;
int hdr_idx;
/* TODO support buffer wrapping */
BUG_ON(b_contig_data(buf, 0) != b_data(buf));
if (qpack_decode_fs((const unsigned char *)b_head(buf), len, tmp, list) < 0)
return 1;
@ -198,23 +200,31 @@ static int h3_data_to_htx(struct qcs *qcs, struct buffer *buf, uint64_t len,
{
struct buffer *appbuf;
struct htx *htx = NULL;
size_t htx_sent;
size_t contig = 0, htx_sent = 0;
int htx_space;
char *head;
appbuf = qc_get_buf(qcs, &qcs->rx.app_buf);
BUG_ON(!appbuf);
htx = htx_from_buf(appbuf);
retry:
htx_space = htx_free_data_space(htx);
if (!htx_space || htx_space < len) {
ABORT_NOW(); /* TODO handle this case properly */
}
htx_sent = htx_add_data(htx, ist2(b_head(buf), len));
if (htx_sent < len) {
ABORT_NOW(); /* TODO handle this case properly */
contig = b_contig_data(buf, contig);
if (len > contig) {
htx_sent = htx_add_data(htx, ist2(b_head(buf), contig));
head = b_orig(buf);
len -= contig;
goto retry;
}
htx_sent += htx_add_data(htx, ist2(head, len));
BUG_ON(htx_sent < len);
if (fin)
htx->flags |= HTX_FL_EOM;
htx_to_buf(htx, appbuf);