From 83ddb3dbba2ee0f1767442ae6ee665058aeb1093 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Date: Tue, 9 Apr 2024 19:54:05 +0200 Subject: [PATCH] hw/net/net_tx_pkt: Fix overrun in update_sctp_checksum() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If a fragmented packet size is too short, do not try to calculate its checksum. Reproduced using: $ cat << EOF | qemu-system-i386 -display none -nodefaults \ -machine q35,accel=qtest -m 32M \ -device igb,netdev=net0 \ -netdev user,id=net0 \ -qtest stdio outl 0xcf8 0x80000810 outl 0xcfc 0xe0000000 outl 0xcf8 0x80000804 outw 0xcfc 0x06 write 0xe0000403 0x1 0x02 writel 0xe0003808 0xffffffff write 0xe000381a 0x1 0x5b write 0xe000381b 0x1 0x00 EOF Assertion failed: (offset == 0), function iov_from_buf_full, file util/iov.c, line 39. #1 0x5575e81e952a in iov_from_buf_full qemu/util/iov.c:39:5 #2 0x5575e6500768 in net_tx_pkt_update_sctp_checksum qemu/hw/net/net_tx_pkt.c:144:9 #3 0x5575e659f3e1 in igb_setup_tx_offloads qemu/hw/net/igb_core.c:478:11 #4 0x5575e659f3e1 in igb_tx_pkt_send qemu/hw/net/igb_core.c:552:10 #5 0x5575e659f3e1 in igb_process_tx_desc qemu/hw/net/igb_core.c:671:17 #6 0x5575e659f3e1 in igb_start_xmit qemu/hw/net/igb_core.c:903:9 #7 0x5575e659f3e1 in igb_set_tdt qemu/hw/net/igb_core.c:2812:5 #8 0x5575e657d6a4 in igb_core_write qemu/hw/net/igb_core.c:4248:9 Fixes: CVE-2024-3567 Cc: qemu-stable@nongnu.org Reported-by: Zheyu Ma Fixes: f199b13bc1 ("igb: Implement Tx SCTP CSO") Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2273 Signed-off-by: Philippe Mathieu-Daudé Reviewed-by: Akihiko Odaki Acked-by: Jason Wang Message-Id: <20240410070459.49112-1-philmd@linaro.org> --- hw/net/net_tx_pkt.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/hw/net/net_tx_pkt.c b/hw/net/net_tx_pkt.c index 2134a18c4c9..b7b1de816dc 100644 --- a/hw/net/net_tx_pkt.c +++ b/hw/net/net_tx_pkt.c @@ -141,6 +141,10 @@ bool net_tx_pkt_update_sctp_checksum(struct NetTxPkt *pkt) uint32_t csum = 0; struct iovec *pl_start_frag = pkt->vec + NET_TX_PKT_PL_START_FRAG; + if (iov_size(pl_start_frag, pkt->payload_frags) < 8 + sizeof(csum)) { + return false; + } + if (iov_from_buf(pl_start_frag, pkt->payload_frags, 8, &csum, sizeof(csum)) < sizeof(csum)) { return false; }