From 0ae4f14e931a55c592cf083d78cc75c7e027550e Mon Sep 17 00:00:00 2001 From: "Huawei Technologies Co., Ltd" Date: Wed, 11 Nov 2020 18:36:36 +0530 Subject: [PATCH] hw/net/e1000e: advance desc_offset in case of null descriptor 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 c2cb5116) Fix CVE-2020-28916 Signed-off-by: Alex Chen --- ...vance-desc_offset-in-case-of-null-de.patch | 46 +++++++++++++++++++ 1 file changed, 46 insertions(+) create mode 100644 hw-net-e1000e-advance-desc_offset-in-case-of-null-de.patch diff --git a/hw-net-e1000e-advance-desc_offset-in-case-of-null-de.patch b/hw-net-e1000e-advance-desc_offset-in-case-of-null-de.patch new file mode 100644 index 0000000..3bffc1c --- /dev/null +++ b/hw-net-e1000e-advance-desc_offset-in-case-of-null-de.patch @@ -0,0 +1,46 @@ +From 2b157688d19da5ce4fca6b5f3c78d2e309ecec9a Mon Sep 17 00:00:00 2001 +From: Prasad J Pandit +Date: Wed, 11 Nov 2020 18:36:36 +0530 +Subject: [PATCH] hw/net/e1000e: advance desc_offset in case of null descriptor + +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 c2cb5116) +Fix CVE-2020-28916 +Signed-off-by: Alex Chen +--- + 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 2a221c2ef9..e45d47f584 100644 +--- a/hw/net/e1000e_core.c ++++ b/hw/net/e1000e_core.c +@@ -1595,13 +1595,13 @@ 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 +