| From affdf476543405045c281a7c67d1eaedbcea8135 Mon Sep 17 00:00:00 2001 |
| From: Jason Wang <jasowang@redhat.com> |
| Date: Wed, 24 Feb 2021 13:45:28 +0800 |
| Subject: [PATCH] e1000: fail early for evil descriptor |
| |
| During procss_tx_desc(), driver can try to chain data descriptor with |
| legacy descriptor, when will lead underflow for the following |
| calculation in process_tx_desc() for bytes: |
| |
| if (tp->size + bytes > msh) |
| bytes = msh - tp->size; |
| |
| This will lead a infinite loop. So check and fail early if tp->size if |
| greater or equal to msh. |
| |
| Reported-by: Alexander Bulekov <alxndr@bu.edu> |
| Reported-by: Cheolwoo Myung <cwmyung@snu.ac.kr> |
| Reported-by: Ruhr-University Bochum <bugs-syssec@rub.de> |
| Cc: Prasad J Pandit <ppandit@redhat.com> |
| Cc: qemu-stable@nongnu.org |
| Signed-off-by: Jason Wang <jasowang@redhat.com> |
| |
| Upstream-Status: Backport [3de46e6fc489c52c9431a8a832ad8170a7569bd8] |
| CVE: CVE-2021-20257 |
| |
| Signed-off-by: Sakib Sajal <sakib.sajal@windriver.com> |
| --- |
| hw/net/e1000.c | 4 ++++ |
| 1 file changed, 4 insertions(+) |
| |
| diff --git a/hw/net/e1000.c b/hw/net/e1000.c |
| index cf22c4f07..c3564c7ce 100644 |
| --- a/hw/net/e1000.c |
| +++ b/hw/net/e1000.c |
| @@ -670,6 +670,9 @@ process_tx_desc(E1000State *s, struct e1000_tx_desc *dp) |
| msh = tp->tso_props.hdr_len + tp->tso_props.mss; |
| do { |
| bytes = split_size; |
| + if (tp->size >= msh) { |
| + goto eop; |
| + } |
| if (tp->size + bytes > msh) |
| bytes = msh - tp->size; |
| |
| @@ -695,6 +698,7 @@ process_tx_desc(E1000State *s, struct e1000_tx_desc *dp) |
| tp->size += split_size; |
| } |
| |
| +eop: |
| if (!(txd_lower & E1000_TXD_CMD_EOP)) |
| return; |
| if (!(tp->cptse && tp->size < tp->tso_props.hdr_len)) { |
| -- |
| 2.29.2 |
| |