https://bugs.gentoo.org/559656 https://lists.gnu.org/archive/html/qemu-devel/2015-09/msg01199.html From: Stefan Hajnoczi Subject: [PATCH] e1000: Avoid infinite loop in processing transmit descriptor Newsgroups: gmane.comp.emulators.qemu Date: 2015-09-04 16:21:06 GMT (2 days, 12 hours and 51 minutes ago) From: P J P While processing transmit descriptors, it could lead to an infinite loop if 'bytes' was to become zero; Add a check to avoid it. [The guest can force 'bytes' to 0 by setting the hdr_len and mss descriptor fields to 0. --Stefan] Signed-off-by: P J P Signed-off-by: Stefan Hajnoczi --- hw/net/e1000.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/net/e1000.c b/hw/net/e1000.c index 5c6bcd0..09c9e9d 100644 --- a/hw/net/e1000.c +++ b/hw/net/e1000.c @@ -740,7 +740,8 @@ process_tx_desc(E1000State *s, struct e1000_tx_desc *dp) memmove(tp->data, tp->header, tp->hdr_len); tp->size = tp->hdr_len; } - } while (split_size -= bytes); + split_size -= bytes; + } while (bytes && split_size); } else if (!tp->tse && tp->cptse) { // context descriptor TSE is not set, while data descriptor TSE is set DBGOUT(TXERR, "TCP segmentation error\n"); -- 2.4.3