From d48034cc2b331313995c1d19060decc0e5ca1356 Mon Sep 17 00:00:00 2001 From: Jon Maloy Date: Thu, 14 Jan 2021 01:35:41 -0500 Subject: [PATCH 17/17] hw/net/e1000e: advance desc_offset in case of null descriptor MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Jon Maloy Message-id: <20210114013541.956735-2-jmaloy@redhat.com> Patchwork-id: 100638 O-Subject: [RHEL-8.4.0 qemu-kvm PATCH 1/1] hw/net/e1000e: advance desc_offset in case of null descriptor Bugzilla: 1903070 RH-Acked-by: Paolo Bonzini RH-Acked-by: Philippe Mathieu-Daudé RH-Acked-by: Thomas Huth From: Prasad J Pandit While receiving packets via e1000e_write_packet_to_guest() routine, 'desc_offset' is advanced only when RX descriptor is processed. And RX descriptor is not processed if it has NULL buffer address. This may lead to an infinite loop condition. Increament 'desc_offset' to process next descriptor in the ring to avoid infinite loop. Reported-by: Cheol-woo Myung <330cjfdn@gmail.com> Signed-off-by: Prasad J Pandit Signed-off-by: Jason Wang (cherry picked from c2cb511634012344e3d0fe49a037a33b12d8a98a) Signed-off-by: Jon Maloy Signed-off-by: Danilo C. L. de Paula --- hw/net/e1000e_core.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/hw/net/e1000e_core.c b/hw/net/e1000e_core.c index 9b76f82db5b..166054f2e3f 100644 --- a/hw/net/e1000e_core.c +++ b/hw/net/e1000e_core.c @@ -1596,13 +1596,13 @@ e1000e_write_packet_to_guest(E1000ECore *core, struct NetRxPkt *pkt, (const char *) &fcs_pad, e1000x_fcs_len(core->mac)); } } - desc_offset += desc_size; - if (desc_offset >= total_size) { - is_last = true; - } } else { /* as per intel docs; skip descriptors with null buf addr */ trace_e1000e_rx_null_descriptor(); } + desc_offset += desc_size; + if (desc_offset >= total_size) { + is_last = true; + } e1000e_write_rx_descr(core, desc, is_last ? core->rx_pkt : NULL, rss_info, do_ps ? ps_hdr_len : 0, &bastate.written); -- 2.27.0