From 035e69b063835a5fd23cacabd63690a3d84532a8 Mon Sep 17 00:00:00 2001 From: Mauro Matteo Cascella Date: Sat, 1 Aug 2020 18:42:38 +0200 Subject: [PATCH] hw/net/net_tx_pkt: fix assertion failure in net_tx_pkt_add_raw_fragment() An assertion failure issue was found in the code that processes network packets while adding data fragments into the packet context. It could be abused by a malicious guest to abort the QEMU process on the host. This patch replaces the affected assert() with a conditional statement, returning false if the current data fragment exceeds max_raw_frags. Reported-by: Alexander Bulekov Reported-by: Ziming Zhang Reviewed-by: Dmitry Fleytman Signed-off-by: Mauro Matteo Cascella Signed-off-by: Jason Wang Upstream-Status: Backport CVE: CVE-2020-16092 [https://git.qemu.org/?p=qemu.git;a=commit;h=035e69b063835a5fd23cacabd63690a3d84532a8] Signed-off-by: Li Wang --- hw/net/net_tx_pkt.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/hw/net/net_tx_pkt.c b/hw/net/net_tx_pkt.c index 162f802..54d4c3b 100644 --- a/hw/net/net_tx_pkt.c +++ b/hw/net/net_tx_pkt.c @@ -379,7 +379,10 @@ bool net_tx_pkt_add_raw_fragment(struct NetTxPkt *pkt, hwaddr pa, hwaddr mapped_len = 0; struct iovec *ventry; assert(pkt); - assert(pkt->max_raw_frags > pkt->raw_frags); + + if (pkt->raw_frags >= pkt->max_raw_frags) { + return false; + } if (!len) { return true; -- 2.17.1