From e5ff72a8005dd1d9c0f63f8a9cc4298df5bb7551 Mon Sep 17 00:00:00 2001 From: Changqing Li Date: Mon, 15 Oct 2018 16:39:46 +0800 Subject: [PATCH] pcnet: fix possible buffer overflow In pcnet_receive(), we try to assign size_ to size which converts from size_t to integer. This will cause troubles when size_ is greater INT_MAX, this will lead a negative value in size and it can then pass the check of size < MIN_BUF_SIZE which may lead out of bound access for both buf and buf1. Fixing by converting the type of size to size_t. CC: address@hidden Reported-by: Daniel Shapira Reviewed-by: Michael S. Tsirkin Signed-off-by: Jason Wang Upstream-Status: Backport [https://lists.gnu.org/archive/html/qemu-devel/2018-09/msg03268.html] CVE: CVE-2018-17963 Signed-off-by: Changqing Li --- hw/net/pcnet.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/hw/net/pcnet.c b/hw/net/pcnet.c index 0c44554..d9ba04b 100644 --- a/hw/net/pcnet.c +++ b/hw/net/pcnet.c @@ -988,14 +988,14 @@ ssize_t pcnet_receive(NetClientState *nc, const uint8_t *buf, size_t size_) uint8_t buf1[60]; int remaining; int crc_err = 0; - int size = size_; + size_t size = size_; if (CSR_DRX(s) || CSR_STOP(s) || CSR_SPND(s) || !size || (CSR_LOOP(s) && !s->looptest)) { return -1; } #ifdef PCNET_DEBUG - printf("pcnet_receive size=%d\n", size); + printf("pcnet_receive size=%zu\n", size); #endif /* if too small buffer, then expand it */ -- 2.7.4