From ec2c8f6ee9d86f4127098083ca5fe3342b61bbbd Mon Sep 17 00:00:00 2001 From: Jouni Malinen Date: Tue, 7 Apr 2015 11:32:11 +0300 Subject: P2P: Validate SSID element length before copying it This fixes a possible memcpy overflow for P2P dev->oper_ssid in p2p_add_device(). The length provided by the peer device (0..255 bytes) was used without proper bounds checking and that could have resulted in arbitrary data of up to 223 bytes being written beyond the end of the dev->oper_ssid[] array (of which about 150 bytes would be beyond the heap allocation) when processing a corrupted management frame for P2P peer discovery purposes. This could result in corrupted state in heap, unexpected program behavior due to corrupted P2P peer device information, denial of service due to process crash, exposure of memory contents during GO Negotiation, and potentially arbitrary code execution. Thanks to Google security team for reporting this issue and smart hardware research group of Alibaba security team for discovering it. Change-Id: I9f350f20cdd010f2c096514b245b4a901ad74e46 Signed-off-by: Jouni Malinen --- src/p2p/p2p.c | 1 + 1 file changed, 1 insertion(+) diff --git a/src/p2p/p2p.c b/src/p2p/p2p.c index a3eaa8c..1238af8 100644 --- a/src/p2p/p2p.c +++ b/src/p2p/p2p.c @@ -674,6 +674,7 @@ int p2p_add_device(struct p2p_data *p2p, const u8 *addr, int freq, int level, if (os_memcmp(addr, p2p_dev_addr, ETH_ALEN) != 0) os_memcpy(dev->interface_addr, addr, ETH_ALEN); if (msg.ssid && + msg.ssid[1] <= sizeof(dev->oper_ssid) && (msg.ssid[1] != P2P_WILDCARD_SSID_LEN || os_memcmp(msg.ssid + 2, P2P_WILDCARD_SSID, P2P_WILDCARD_SSID_LEN) != 0)) { -- cgit v1.1